[RBW] Re: Tire Width and Performance from SCHWALBE
The way I wrapped my head around it is that 3 ( at least ) different phenomena are involved; tire internal friction, tire contact patch ( external friction ), and vibration damping of the entire assembly ( Tires, Bike, Human). At very low pressure tire internal friction is high and tire contact patch is large but vibration is absorbed at the tire ( and not transmitted up into the assembly). Within moderate pressure there are sweet spots where the balance optimizes for low rolling resistance and low levels of vibration passing up into the assembly ( fast and comfortable ) . At high moderate no one is happy ( tire is still flexing, contact patch is still relatively large, and a lot of the vibration is passing up to be damped by the human in the assembly). At very high pressure internal friction is very low ( no flex in the tire ), external friction is very low ( contact patch has become tiny ), and vibration is transmitted almost directly into the assembly. The balance is out of whack but favors low rolling resistance. What Jan has found is that with good tire design and half an eye on the pressures we can enjoy a large sweet spot where a low work load, a comfortable chair AND high productivity reside. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
Of course you are quite right that this is of no importance when we go ride our bikes, but when experimental data seems to contradict our understanding of how something works I like to find at least a possible explanation. Don't you? I'm no engineer and my graduate degree has nothing to do with science. But will hazard to say it occurs to me that rubber and air can only yield so hard a surface before the tire explodes. Declining changes in figures from 140 to 200 could reflect that what you find at 140 is about all you are going to get with the component at hand. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
We just tested the tires and recorded the results – I only can offer hypotheses why the tires behave that way. A likely explanation is that the decrease in hysteretic losses becomes smaller once you exceed a certain pressure, but the suspension losses still increase with higher pressures. (You don't get much less flex in the tire, but you still increase the vibrations as you go to higher pressures.) When you look at the original data in Bicycle Quarterly Vol. 11, No. 3, you'll see that different tire models (we tested three different tires in 0.5 bar increments) behave a bit differently, as you'd expect. As a rider, I don't really care why my tires roll as fast at 50 psi as they do at 100 psi, I am just glad I can get tires that are wide and comfortable, and roll fast. Jan Heine Editor Bicycle Quarterly http://www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ On Monday, January 6, 2014 4:44:13 PM UTC-8, ted wrote: Jan, Agreed on the practical practice side, but I am still curious about the med hi to hi pressure phenomena. If I understand correctly, you say that from nominal to very high pressure, losses in the tire itself decrease. But from nominal to moderately high pressures, suspension losses increase more and overwhelm the reduction in losses in the tire so that the total resistance increases. However from moderately high to very high pressure total resistance decreases. Do you have a theory / explanation for that? What component of the total resistance goes down with increasing pressure in that medium to very high pressure regime? Though it's not significant as a practical matter, somehow the engineer in me still wants to know. On Sunday, January 5, 2014 6:50:27 PM UTC-8, Jan Heine wrote: On Sunday, January 5, 2014 5:45:23 PM UTC-8, ted wrote: If I read that right, you are saying that your data shows a local maxima at medium-high pressure with lower losses at tire pressures both above and below that point. Is that really what you mean to be saying? Yes, that is what we found. (There is a second maximum at very low pressures, like below 40 psi for a 25 mm tire). As you point out, the differences, while statistically significant (we had so much data that it was easy to filter out the noise), don't really matter in real life. Just ride really is a good way to think about tire pressure. It's nice to know that obsessing about tire pressure doesn't gain you anything. I now inflate my Grand Bois Hetres to about 45 psi, and then ride them for a few months, until they start washing out under hard cornering, at which point I inflate them again. It's nice not to worry about tire pressure more than a few times a year. I do reduce the pressure if we are heading over long, rough gravel sections, but then I hardly ever re-inflate them even if we are riding for hundreds of miles on pavement thereafter. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance from SCHWALBE
What about rider/ bike weight? On Saturday, January 4, 2014 7:46:07 AM UTC-5, Charlie wrote: http://www.schwalbetires.com/tech_info/rolling_resistance#why Another view on tire performance. Guess they do not use the same hill that Mr. Heine uses, or the same type of testing. Charlie Petry Snow riding today in Jennersville PA -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
I don't see how this relates to my question. I think it is a possible (or even probable) explanation for resistance increasing as pressure increases from nominal to moderately high values. My question is what could explain resistance then decreasing as pressure continues to increase from moderately high to very high levels? I think the hypothesis you present is inconsistent with that aspect of your experiments results. As the tire gets harder wouldn't the suspension losses continue to increase? Aren't the reductions in losses in the tire itself likely to continue to become smaller and smaller, or even reverse? What can possibly explain resistance decreasing as tire pressure increases from 140 to 200 psi if resistance had already gone through a local minimum below 140 psi? Of course you are quite right that this is of no importance when we go ride our bikes, but when experimental data seems to contradict our understanding of how something works I like to find at least a possible explanation. Don't you? On Tuesday, January 7, 2014 11:18:30 AM UTC-8, Jan Heine wrote: We just tested the tires and recorded the results – I only can offer hypotheses why the tires behave that way. A likely explanation is that the decrease in hysteretic losses becomes smaller once you exceed a certain pressure, but the suspension losses still increase with higher pressures. (You don't get much less flex in the tire, but you still increase the vibrations as you go to higher pressures.) When you look at the original data in Bicycle Quarterly Vol. 11, No. 3, you'll see that different tire models (we tested three different tires in 0.5 bar increments) behave a bit differently, as you'd expect. As a rider, I don't really care why my tires roll as fast at 50 psi as they do at 100 psi, I am just glad I can get tires that are wide and comfortable, and roll fast. Jan Heine Editor Bicycle Quarterly http://www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ On Monday, January 6, 2014 4:44:13 PM UTC-8, ted wrote: Jan, Agreed on the practical practice side, but I am still curious about the med hi to hi pressure phenomena. If I understand correctly, you say that from nominal to very high pressure, losses in the tire itself decrease. But from nominal to moderately high pressures, suspension losses increase more and overwhelm the reduction in losses in the tire so that the total resistance increases. However from moderately high to very high pressure total resistance decreases. Do you have a theory / explanation for that? What component of the total resistance goes down with increasing pressure in that medium to very high pressure regime? Though it's not significant as a practical matter, somehow the engineer in me still wants to know. On Sunday, January 5, 2014 6:50:27 PM UTC-8, Jan Heine wrote: On Sunday, January 5, 2014 5:45:23 PM UTC-8, ted wrote: If I read that right, you are saying that your data shows a local maxima at medium-high pressure with lower losses at tire pressures both above and below that point. Is that really what you mean to be saying? Yes, that is what we found. (There is a second maximum at very low pressures, like below 40 psi for a 25 mm tire). As you point out, the differences, while statistically significant (we had so much data that it was easy to filter out the noise), don't really matter in real life. Just ride really is a good way to think about tire pressure. It's nice to know that obsessing about tire pressure doesn't gain you anything. I now inflate my Grand Bois Hetres to about 45 psi, and then ride them for a few months, until they start washing out under hard cornering, at which point I inflate them again. It's nice not to worry about tire pressure more than a few times a year. I do reduce the pressure if we are heading over long, rough gravel sections, but then I hardly ever re-inflate them even if we are riding for hundreds of miles on pavement thereafter. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
I look forward to your results, Ted. On Jan 7, 2014 9:42 PM, ted ted.ke...@comcast.net wrote: I don't see how this relates to my question. I think it is a possible (or even probable) explanation for resistance increasing as pressure increases from nominal to moderately high values. My question is what could explain resistance then decreasing as pressure continues to increase from moderately high to very high levels? I think the hypothesis you present is inconsistent with that aspect of your experiments results. As the tire gets harder wouldn't the suspension losses continue to increase? Aren't the reductions in losses in the tire itself likely to continue to become smaller and smaller, or even reverse? What can possibly explain resistance decreasing as tire pressure increases from 140 to 200 psi if resistance had already gone through a local minimum below 140 psi? Of course you are quite right that this is of no importance when we go ride our bikes, but when experimental data seems to contradict our understanding of how something works I like to find at least a possible explanation. Don't you? On Tuesday, January 7, 2014 11:18:30 AM UTC-8, Jan Heine wrote: We just tested the tires and recorded the results – I only can offer hypotheses why the tires behave that way. A likely explanation is that the decrease in hysteretic losses becomes smaller once you exceed a certain pressure, but the suspension losses still increase with higher pressures. (You don't get much less flex in the tire, but you still increase the vibrations as you go to higher pressures.) When you look at the original data in Bicycle Quarterly Vol. 11, No. 3, you'll see that different tire models (we tested three different tires in 0.5 bar increments) behave a bit differently, as you'd expect. As a rider, I don't really care why my tires roll as fast at 50 psi as they do at 100 psi, I am just glad I can get tires that are wide and comfortable, and roll fast. Jan Heine Editor Bicycle Quarterly http://www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ On Monday, January 6, 2014 4:44:13 PM UTC-8, ted wrote: Jan, Agreed on the practical practice side, but I am still curious about the med hi to hi pressure phenomena. If I understand correctly, you say that from nominal to very high pressure, losses in the tire itself decrease. But from nominal to moderately high pressures, suspension losses increase more and overwhelm the reduction in losses in the tire so that the total resistance increases. However from moderately high to very high pressure total resistance decreases. Do you have a theory / explanation for that? What component of the total resistance goes down with increasing pressure in that medium to very high pressure regime? Though it's not significant as a practical matter, somehow the engineer in me still wants to know. On Sunday, January 5, 2014 6:50:27 PM UTC-8, Jan Heine wrote: On Sunday, January 5, 2014 5:45:23 PM UTC-8, ted wrote: If I read that right, you are saying that your data shows a local maxima at medium-high pressure with lower losses at tire pressures both above and below that point. Is that really what you mean to be saying? Yes, that is what we found. (There is a second maximum at very low pressures, like below 40 psi for a 25 mm tire). As you point out, the differences, while statistically significant (we had so much data that it was easy to filter out the noise), don't really matter in real life. Just ride really is a good way to think about tire pressure. It's nice to know that obsessing about tire pressure doesn't gain you anything. I now inflate my Grand Bois Hetres to about 45 psi, and then ride them for a few months, until they start washing out under hard cornering, at which point I inflate them again. It's nice not to worry about tire pressure more than a few times a year. I do reduce the pressure if we are heading over long, rough gravel sections, but then I hardly ever re-inflate them even if we are riding for hundreds of miles on pavement thereafter. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
Just don't hold your breath. On Tuesday, January 7, 2014 9:48:36 PM UTC-8, Christopher Chen wrote: I look forward to your results, Ted. On Jan 7, 2014 9:42 PM, ted ted@comcast.net javascript: wrote: I don't see how this relates to my question. I think it is a possible (or even probable) explanation for resistance increasing as pressure increases from nominal to moderately high values. My question is what could explain resistance then decreasing as pressure continues to increase from moderately high to very high levels? I think the hypothesis you present is inconsistent with that aspect of your experiments results. As the tire gets harder wouldn't the suspension losses continue to increase? Aren't the reductions in losses in the tire itself likely to continue to become smaller and smaller, or even reverse? What can possibly explain resistance decreasing as tire pressure increases from 140 to 200 psi if resistance had already gone through a local minimum below 140 psi? Of course you are quite right that this is of no importance when we go ride our bikes, but when experimental data seems to contradict our understanding of how something works I like to find at least a possible explanation. Don't you? On Tuesday, January 7, 2014 11:18:30 AM UTC-8, Jan Heine wrote: We just tested the tires and recorded the results – I only can offer hypotheses why the tires behave that way. A likely explanation is that the decrease in hysteretic losses becomes smaller once you exceed a certain pressure, but the suspension losses still increase with higher pressures. (You don't get much less flex in the tire, but you still increase the vibrations as you go to higher pressures.) When you look at the original data in Bicycle Quarterly Vol. 11, No. 3, you'll see that different tire models (we tested three different tires in 0.5 bar increments) behave a bit differently, as you'd expect. As a rider, I don't really care why my tires roll as fast at 50 psi as they do at 100 psi, I am just glad I can get tires that are wide and comfortable, and roll fast. Jan Heine Editor Bicycle Quarterly http://www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ On Monday, January 6, 2014 4:44:13 PM UTC-8, ted wrote: Jan, Agreed on the practical practice side, but I am still curious about the med hi to hi pressure phenomena. If I understand correctly, you say that from nominal to very high pressure, losses in the tire itself decrease. But from nominal to moderately high pressures, suspension losses increase more and overwhelm the reduction in losses in the tire so that the total resistance increases. However from moderately high to very high pressure total resistance decreases. Do you have a theory / explanation for that? What component of the total resistance goes down with increasing pressure in that medium to very high pressure regime? Though it's not significant as a practical matter, somehow the engineer in me still wants to know. On Sunday, January 5, 2014 6:50:27 PM UTC-8, Jan Heine wrote: On Sunday, January 5, 2014 5:45:23 PM UTC-8, ted wrote: If I read that right, you are saying that your data shows a local maxima at medium-high pressure with lower losses at tire pressures both above and below that point. Is that really what you mean to be saying? Yes, that is what we found. (There is a second maximum at very low pressures, like below 40 psi for a 25 mm tire). As you point out, the differences, while statistically significant (we had so much data that it was easy to filter out the noise), don't really matter in real life. Just ride really is a good way to think about tire pressure. It's nice to know that obsessing about tire pressure doesn't gain you anything. I now inflate my Grand Bois Hetres to about 45 psi, and then ride them for a few months, until they start washing out under hard cornering, at which point I inflate them again. It's nice not to worry about tire pressure more than a few times a year. I do reduce the pressure if we are heading over long, rough gravel sections, but then I hardly ever re-inflate them even if we are riding for hundreds of miles on pavement thereafter. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bun...@googlegroups.com javascript:. To post to this group, send email to rbw-owne...@googlegroups.comjavascript: . Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
Jan, Agreed on the practical practice side, but I am still curious about the med hi to hi pressure phenomena. If I understand correctly, you say that from nominal to very high pressure, losses in the tire itself decrease. But from nominal to moderately high pressures, suspension losses increase more and overwhelm the reduction in losses in the tire so that the total resistance increases. However from moderately high to very high pressure total resistance decreases. Do you have a theory / explanation for that? What component of the total resistance goes down with increasing pressure in that medium to very high pressure regime? Though it's not significant as a practical matter, somehow the engineer in me still wants to know. On Sunday, January 5, 2014 6:50:27 PM UTC-8, Jan Heine wrote: On Sunday, January 5, 2014 5:45:23 PM UTC-8, ted wrote: If I read that right, you are saying that your data shows a local maxima at medium-high pressure with lower losses at tire pressures both above and below that point. Is that really what you mean to be saying? Yes, that is what we found. (There is a second maximum at very low pressures, like below 40 psi for a 25 mm tire). As you point out, the differences, while statistically significant (we had so much data that it was easy to filter out the noise), don't really matter in real life. Just ride really is a good way to think about tire pressure. It's nice to know that obsessing about tire pressure doesn't gain you anything. I now inflate my Grand Bois Hetres to about 45 psi, and then ride them for a few months, until they start washing out under hard cornering, at which point I inflate them again. It's nice not to worry about tire pressure more than a few times a year. I do reduce the pressure if we are heading over long, rough gravel sections, but then I hardly ever re-inflate them even if we are riding for hundreds of miles on pavement thereafter. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance from SCHWALBE
I realized that my previous blog post may be misunderstood as saying that width is all that matters for tire speed. In fact, it's a minor component - it's just that when you are comparing tires of similar construction, wider tires offer you more comfort and as much or more speed. To clarify, I posted a list of tires that we've found to offer excellent performance in our testing: http://janheine.wordpress.com/2014/01/05/wide-and-fast-tires/ Jan Heine Editor Bicycle Quarterly www.bikequarterly.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance from SCHWALBE
On Saturday, January 4, 2014 10:59:41 PM UTC-8, ted wrote: Are you equating the behavior of high performance 32mm clinchers and 25mm tubulars, or are both tires you mention clinchers? I am just talking about test results. We tested the Grand Bois clinchers, as well as the Vittorias as clinchers and tubulars at a multitude of pressures. The results were the same - ultra-high-pressures don't provide any benefit, even on very smooth roads. For more information, I recommend you read the original article - there are dozens of pages on tire performance in that issue (Vol. 11, No. 3), much more than I can summarize in this format. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
Interestingly that is pretty much in keeping with the traditional rolling resistance tests done in tire labs. The decrease in rolling resistance flattens out as inflation pressure increases. Even on a steel roller, an increase from 100 to 140 psi doesn't reduce rolling resistance that much. Interestingly in the old Avocet tests, that flattening was more pronounced in tubulars than in clicnhers. Those were also- as far as I know- the first published tests hinting at lower RR with wider tires. Tire pressure needs to be high enough to prevent pinch flats. At my weight (6'4 and roughly 220 lbs these days, more in midwinter when I am not riding due to snow, ice and cold) I pretty much have to run tires 32 mm or narrower at the top end of the rated pressure on the rear, and run the same at the front for no particular reason. At 23 mm I have to run them at 120 psi or lose weight... ;-) Interestingly enough the comfort of my 559x32 Paselas at 100 psi is very similar to my 700x25 Paselas at 115. On Jan 5, 2014, at 7:29 AM, Jan Heine hein...@earthlink.net wrote: On Saturday, January 4, 2014 10:59:41 PM UTC-8, ted wrote: Are you equating the behavior of high performance 32mm clinchers and 25mm tubulars, or are both tires you mention clinchers? I am just talking about test results. We tested the Grand Bois clinchers, as well as the Vittorias as clinchers and tubulars at a multitude of pressures. The results were the same - ultra-high-pressures don't provide any benefit, even on very smooth roads. For more information, I recommend you read the original article - there are dozens of pages on tire performance in that issue (Vol. 11, No. 3), much more than I can summarize in this format. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance
Jan or anyone else, I think this is just a slight expansion of the topic rather than new-thread worthy (apologies if I'm wrong). Does anyone know info on tire width for off road. Once the volume gets past standard MTB tire widths (2-2.35) the 3 size gets very heavy, but no doubt rolls more efficiently over larger obstacles. Aside from feel, is there any info out there to help assess the quandary? For context, I'm looking for the ideal tire size for me doing remote multi-day touring (and who know, my current 2.1 Smart Sams may be it). With abandon, Patrick -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance
Good point, Steve. Between those two. Like this: http://www.flickr.com/photos/32311885@N07/9360337251/in/set-72157634780609741 With abandon, Patrick On Sunday, January 5, 2014 9:46:29 AM UTC-7, Steve Palincsar wrote: On 01/05/2014 11:39 AM, Deacon Patrick wrote: Jan or anyone else, I think this is just a slight expansion of the topic rather than new-thread worthy (apologies if I'm wrong). Does anyone know info on tire width for off road. Once the volume gets past standard MTB tire widths (2-2.35) the 3 size gets very heavy, but no doubt rolls more efficiently over larger obstacles. Aside from feel, is there any info out there to help assess the quandary? For context, I'm looking for the ideal tire size for me doing remote multi-day touring (and who know, my current 2.1 Smart Sams may be it). Surely this must depend on what you mean by off road.Something like this: would require a completely different tire than something like this: I've been on the one above (in color). Col de la Vie tires were perfect on it. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
Indeed, and given the relationships between load, width, and pressure, I suspect how wide is wide enough depends on weight (of the rider that is). I am much shorter and roughly 65lbs lighter than you (which is about 30% less) and I run 32mm tires down around 55 or 65 psi. these days. Decades ago I went from riding garden variety 27 clinchers at ~80 psi to hand made 700c tubulars at 100+psi. The tubulars were way more comfortable. I only ever got one pinch flat riding tubulars, and that event also ruined the wheel. So we want to use lower pressure for more comfort (and per Jan less suspension losses), to avoid pinch flats many riders then need bigger tires, which in turn need to have even lower pressure to stay comfortable, which hopefully doesn't then lead to still getting pinch flats. Add to that questions of hysteresis losses in the casing, and changing contact patch shapes and sizes, and you have a complex system. I think some of the admonitions I read about what is true and or has been proven about bike tires over simplify things, and/or are over broad. I will be surprised if optimal tire width and pressure are not related to load (unless it turns out any optimum is so weak that it hardly matters what you use). Does anybody else remember Jobst asserting back in the early 90s that tubulars were slower than clinchers because of the glue? I think the ... flattening was more pronounced in tubulars than clinchers. that Tim mentions was part of his reasoning. On Sunday, January 5, 2014 8:32:54 AM UTC-8, Tim McNamara wrote: Interestingly that is pretty much in keeping with the traditional rolling resistance tests done in tire labs. The decrease in rolling resistance flattens out as inflation pressure increases. Even on a steel roller, an increase from 100 to 140 psi doesn't reduce rolling resistance that much. Interestingly in the old Avocet tests, that flattening was more pronounced in tubulars than in clicnhers. Those were also- as far as I know- the first published tests hinting at lower RR with wider tires. Tire pressure needs to be high enough to prevent pinch flats. At my weight (6'4 and roughly 220 lbs these days, more in midwinter when I am not riding due to snow, ice and cold) I pretty much have to run tires 32 mm or narrower at the top end of the rated pressure on the rear, and run the same at the front for no particular reason. At 23 mm I have to run them at 120 psi or lose weight... ;-) Interestingly enough the comfort of my 559x32 Paselas at 100 psi is very similar to my 700x25 Paselas at 115. On Jan 5, 2014, at 7:29 AM, Jan Heine hei...@earthlink.net javascript: wrote: On Saturday, January 4, 2014 10:59:41 PM UTC-8, ted wrote: Are you equating the behavior of high performance 32mm clinchers and 25mm tubulars, or are both tires you mention clinchers? I am just talking about test results. We tested the Grand Bois clinchers, as well as the Vittorias as clinchers and tubulars at a multitude of pressures. The results were the same - ultra-high-pressures don't provide any benefit, even on very smooth roads. For more information, I recommend you read the original article - there are dozens of pages on tire performance in that issue (Vol. 11, No. 3), much more than I can summarize in this format. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bun...@googlegroups.com javascript:. To post to this group, send email to rbw-owne...@googlegroups.comjavascript: . Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance
Patrick, Based on the trails in your picture, you might really enjoy the 3 tires of the 29+ bikes. I've been experimenting with a 29+ on the front of my rigid mountain bike, and it's been good so far, significantly smoother than the 2.2 Schwalbe Rocket Ron I had on previously--however, I can't give a definitive thumbs up until I can hit the dry trails... in the summer. Man, that seems like a long ways away. I put up some pics and comments here, along with bonus hatchet news! http://bikingtoplay.blogspot.com/2014/01/bike-and-hatchet-update.html Eric Daume Dublin, OH On Sun, Jan 5, 2014 at 11:50 AM, Deacon Patrick lamontg...@mac.com wrote: Good point, Steve. Between those two. Like this: http://www.flickr.com/photos/32311885@N07/9360337251/in/set-72157634780609741 With abandon, Patrick On Sunday, January 5, 2014 9:46:29 AM UTC-7, Steve Palincsar wrote: On 01/05/2014 11:39 AM, Deacon Patrick wrote: Jan or anyone else, I think this is just a slight expansion of the topic rather than new-thread worthy (apologies if I'm wrong). Does anyone know info on tire width for off road. Once the volume gets past standard MTB tire widths (2-2.35) the 3 size gets very heavy, but no doubt rolls more efficiently over larger obstacles. Aside from feel, is there any info out there to help assess the quandary? For context, I'm looking for the ideal tire size for me doing remote multi-day touring (and who know, my current 2.1 Smart Sams may be it). Surely this must depend on what you mean by off road.Something like this: would require a completely different tire than something like this: I've been on the one above (in color). Col de la Vie tires were perfect on it. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance
Thanks, Eric. I plan on trying a 29er+ sometime this coming year. Though if at all possible, I'd love to make the Hunqapillar work. I am very optimistic I can, but as you say, Summer seems a long way off. With abandon, Patrick On Sunday, January 5, 2014 1:55:16 PM UTC-7, Eric Daume wrote: Patrick, Based on the trails in your picture, you might really enjoy the 3 tires of the 29+ bikes. I've been experimenting with a 29+ on the front of my rigid mountain bike, and it's been good so far, significantly smoother than the 2.2 Schwalbe Rocket Ron I had on previously--however, I can't give a definitive thumbs up until I can hit the dry trails... in the summer. Man, that seems like a long ways away. I put up some pics and comments here, along with bonus hatchet news! http://bikingtoplay.blogspot.com/2014/01/bike-and-hatchet-update.html Eric Daume Dublin, OH -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
On Sunday, January 5, 2014 8:32:54 AM UTC-8, Tim McNamara wrote: Interestingly that is pretty much in keeping with the traditional rolling resistance tests done in tire labs. The decrease in rolling resistance flattens out as inflation pressure increases. Even on a steel roller, an increase from 100 to 140 psi doesn't reduce rolling resistance that much. All the steel drum tests don't measure the suspension losses, even though they are a very important part of the equation. Our tests on real roads with a rider on board found that the curve didn't just flatten, but it was U-shaped (if you disregard the really low pressures). Low and very high pressures were marginally more efficient than medium-high pressures. So the curve looks fundamentally different from that you find in steel drum tests. If you believed that data, you'd still gain a small advantage going from 100 to 140 psi. In real life, you might actually be slower at 140 psi. (Where the least efficient point in the curve is depends on the tire type.) Similarly, on real roads, the tubular disadvantage is much smaller because tubulars are more comfortable and thus have lower suspension losses. This counteracts to a large degree the slightly higher hysteretic losses or glue creep or whatever it is that makes them less efficient on the steel drum. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance
If that Hunqapillar needs a good home I know a guy named Peter who would graciously take it off your hands :-) On Jan 5, 2014 4:20 PM, Deacon Patrick lamontg...@mac.com wrote: Thanks, Eric. I plan on trying a 29er+ sometime this coming year. Though if at all possible, I'd love to make the Hunqapillar work. I am very optimistic I can, but as you say, Summer seems a long way off. With abandon, Patrick On Sunday, January 5, 2014 1:55:16 PM UTC-7, Eric Daume wrote: Patrick, Based on the trails in your picture, you might really enjoy the 3 tires of the 29+ bikes. I've been experimenting with a 29+ on the front of my rigid mountain bike, and it's been good so far, significantly smoother than the 2.2 Schwalbe Rocket Ron I had on previously--however, I can't give a definitive thumbs up until I can hit the dry trails... in the summer. Man, that seems like a long ways away. I put up some pics and comments here, along with bonus hatchet news! http://bikingtoplay.blogspot.com/2014/01/bike-and-hatchet-update.html Eric Daume Dublin, OH -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance
Understandable, but don't hold your breath, Peter. Either way, I keeping it. Grin. With abandon, Patrick On Sunday, January 5, 2014 4:21:35 PM UTC-7, Peter M wrote: If that Hunqapillar needs a good home I know a guy named Peter who would graciously take it off your hands :-) On Jan 5, 2014 4:20 PM, Deacon Patrick lamon...@mac.com javascript: wrote: Thanks, Eric. I plan on trying a 29er+ sometime this coming year. Though if at all possible, I'd love to make the Hunqapillar work. I am very optimistic I can, but as you say, Summer seems a long way off. With abandon, Patrick On Sunday, January 5, 2014 1:55:16 PM UTC-7, Eric Daume wrote: Patrick, Based on the trails in your picture, you might really enjoy the 3 tires of the 29+ bikes. I've been experimenting with a 29+ on the front of my rigid mountain bike, and it's been good so far, significantly smoother than the 2.2 Schwalbe Rocket Ron I had on previously--however, I can't give a definitive thumbs up until I can hit the dry trails... in the summer. Man, that seems like a long ways away. I put up some pics and comments here, along with bonus hatchet news! http://bikingtoplay.blogspot.com/2014/01/bike-and-hatchet-update.html Eric Daume Dublin, OH -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bun...@googlegroups.com javascript:. To post to this group, send email to rbw-owne...@googlegroups.comjavascript: . Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
Jan, You wrote: Low and very high pressures were marginally more efficient than medium-high pressures. If I read that right, you are saying that your data shows a local maxima at medium-high pressure with lower losses at tire pressures both above and below that point. Is that really what you mean to be saying? Assuming that you are not really saying the curve is flipped I agree with Tim, whether the insignificant but measurable change in resistance due to going from 100psi to 140psi is positive or negative it is still insignificant and the results are generally speaking pretty much consistent. If you really mean the shape of the curve is flipped, then I don't think your results pass basic sanity checking and maybe you should revisit your margin of error assessment. On Sunday, January 5, 2014 3:21:42 PM UTC-8, Jan Heine wrote: On Sunday, January 5, 2014 8:32:54 AM UTC-8, Tim McNamara wrote: Interestingly that is pretty much in keeping with the traditional rolling resistance tests done in tire labs. The decrease in rolling resistance flattens out as inflation pressure increases. Even on a steel roller, an increase from 100 to 140 psi doesn't reduce rolling resistance that much. All the steel drum tests don't measure the suspension losses, even though they are a very important part of the equation. Our tests on real roads with a rider on board found that the curve didn't just flatten, but it was U-shaped (if you disregard the really low pressures). Low and very high pressures were marginally more efficient than medium-high pressures. So the curve looks fundamentally different from that you find in steel drum tests. If you believed that data, you'd still gain a small advantage going from 100 to 140 psi. In real life, you might actually be slower at 140 psi. (Where the least efficient point in the curve is depends on the tire type.) Similarly, on real roads, the tubular disadvantage is much smaller because tubulars are more comfortable and thus have lower suspension losses. This counteracts to a large degree the slightly higher hysteretic losses or glue creep or whatever it is that makes them less efficient on the steel drum. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
just ride On Jan 5, 2014 8:45 PM, ted ted.ke...@comcast.net wrote: Jan, You wrote: Low and very high pressures were marginally more efficient than medium-high pressures. If I read that right, you are saying that your data shows a local maxima at medium-high pressure with lower losses at tire pressures both above and below that point. Is that really what you mean to be saying? Assuming that you are not really saying the curve is flipped I agree with Tim, whether the insignificant but measurable change in resistance due to going from 100psi to 140psi is positive or negative it is still insignificant and the results are generally speaking pretty much consistent. If you really mean the shape of the curve is flipped, then I don't think your results pass basic sanity checking and maybe you should revisit your margin of error assessment. On Sunday, January 5, 2014 3:21:42 PM UTC-8, Jan Heine wrote: On Sunday, January 5, 2014 8:32:54 AM UTC-8, Tim McNamara wrote: Interestingly that is pretty much in keeping with the traditional rolling resistance tests done in tire labs. The decrease in rolling resistance flattens out as inflation pressure increases. Even on a steel roller, an increase from 100 to 140 psi doesn't reduce rolling resistance that much. All the steel drum tests don't measure the suspension losses, even though they are a very important part of the equation. Our tests on real roads with a rider on board found that the curve didn't just flatten, but it was U-shaped (if you disregard the really low pressures). Low and very high pressures were marginally more efficient than medium-high pressures. So the curve looks fundamentally different from that you find in steel drum tests. If you believed that data, you'd still gain a small advantage going from 100 to 140 psi. In real life, you might actually be slower at 140 psi. (Where the least efficient point in the curve is depends on the tire type.) Similarly, on real roads, the tubular disadvantage is much smaller because tubulars are more comfortable and thus have lower suspension losses. This counteracts to a large degree the slightly higher hysteretic losses or glue creep or whatever it is that makes them less efficient on the steel drum. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
On Sunday, January 5, 2014 5:45:23 PM UTC-8, ted wrote: If I read that right, you are saying that your data shows a local maxima at medium-high pressure with lower losses at tire pressures both above and below that point. Is that really what you mean to be saying? Yes, that is what we found. (There is a second maximum at very low pressures, like below 40 psi for a 25 mm tire). As you point out, the differences, while statistically significant (we had so much data that it was easy to filter out the noise), don't really matter in real life. Just ride really is a good way to think about tire pressure. It's nice to know that obsessing about tire pressure doesn't gain you anything. I now inflate my Grand Bois Hetres to about 45 psi, and then ride them for a few months, until they start washing out under hard cornering, at which point I inflate them again. It's nice not to worry about tire pressure more than a few times a year. I do reduce the pressure if we are heading over long, rough gravel sections, but then I hardly ever re-inflate them even if we are riding for hundreds of miles on pavement thereafter. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
I pump up the Hetres, give em a squeeze and ride! On Jan 5, 2014 9:50 PM, Jan Heine hein...@earthlink.net wrote: On Sunday, January 5, 2014 5:45:23 PM UTC-8, ted wrote: If I read that right, you are saying that your data shows a local maxima at medium-high pressure with lower losses at tire pressures both above and below that point. Is that really what you mean to be saying? Yes, that is what we found. (There is a second maximum at very low pressures, like below 40 psi for a 25 mm tire). As you point out, the differences, while statistically significant (we had so much data that it was easy to filter out the noise), don't really matter in real life. Just ride really is a good way to think about tire pressure. It's nice to know that obsessing about tire pressure doesn't gain you anything. I now inflate my Grand Bois Hetres to about 45 psi, and then ride them for a few months, until they start washing out under hard cornering, at which point I inflate them again. It's nice not to worry about tire pressure more than a few times a year. I do reduce the pressure if we are heading over long, rough gravel sections, but then I hardly ever re-inflate them even if we are riding for hundreds of miles on pavement thereafter. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance from SCHWALBE
Schwalbe's graph is nice, but unfortunately, it's an ancient graph that has long been debunked. While it shows wider tires rolling faster, it also suggests that very high pressures make tires roll faster. That simply isn't true. We've used several different methods to confirm our initial results that going to very high pressures doesn't gain better performance. The Schwalbe data probably stems from a test on a steel roller. Without a rider, you don't measure the suspension losses that occur in the rider's body, and so you get only half the resistance. As tire pressure increases, the bike vibrates more, which increases the suspension losses and cancels out any gain from reduced flex in the tire casing. More about suspension losses is here: http://janheine.wordpress.com/2012/08/12/suspension-losses/ Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance from SCHWALBE
As Jan Heine has often pointed out, his methodology is significantly different than that of most tire manufacturers. Despite that, what I get reading the article you linked to seems fairly consistent with what I think Jan has written. 1) All other things being equal a tire with lighter more supple structure will have less rolling resistance. 2) All other things being equal a wider tire will have lower rolling resistance than a narrower one. 3) For a given tire increasing pressure reduces rolling resistance (on smooth surface or neglecting suspension losses), but at very low pressure this change is larger than at higher pressures, and as pressure increases the effect becomes negligable. Though neither Jan nor Schwalbe seem to mention this, I was once told by a tire engineer that if you increase tire pressure enough the rolling resistance increases. His explanation for this was that vertical compression losses in the contact patch (and or road bed) became larger than the bending losses. 4) In practice a more compliant tire saves energy because less vibration/shock is transmitted to the rider. Jan calls this suspension losses and includes it in his definition of rolling resistance. Schwalbe leaves this component out of their enumeration of loss types at the head of the article, but they allude to it in the last sentence of the section titled why do pros ride narrow tires if wide tires roll better?. On Saturday, January 4, 2014 4:46:07 AM UTC-8, Charlie wrote: http://www.schwalbetires.com/tech_info/rolling_resistance#why Another view on tire performance. Guess they do not use the same hill that Mr. Heine uses, or the same type of testing. Charlie Petry Snow riding today in Jennersville PA -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
IIRC, Jan has asked aloud if there is a point where wider might begin to make a tire slower. Has this been answered? Also, has he or anyone else determined that a 23 mm Pro Race 3 is slower than a 25 mm on a very smooth road? A 19mm? On glass? In brief, is there a breadth below which an otherwise identical tire is always slower even on the best of surfaces? On the other hand, is there a point where, even on rough surfaces, a wider tire is not faster than a narrower one? 60 mm? 70 mm? 100 mm? Will they ride Pugsleys in Paris Roubaix? Patrick Moore, asking seriously despite the flippancy, who does plan to replace his Pro Race 23s with 25s. On Sat, Jan 4, 2014 at 1:17 PM, ted ted.ke...@comcast.net wrote: 2) All other things being equal a wider tire will have lower rolling resistance than a narrower one. -- Burque (NM) Resumes that get interviews: http://www.resumespecialties.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
On 01/04/2014 04:17 PM, Patrick Moore wrote: Also, has he or anyone else determined that a 23 mm Pro Race 3 is slower than a 25 mm on a very smooth road? He has tested the Pro2Race in all 3 sizes and found that; and as I recall, he quoted Michelin in the article as saying the same thing. A 19mm? In BQ's test the 25 was faster than the 23 which in turn was faster than the 21. They didn't test a 19mm. On glass? I'm tempted to say something like On glass, all 3 sizes go PSSS equally but otherwise, who rides much on glass-smooth surfaces? In brief, is there a breadth below which an otherwise identical tire is always slower even on the best of surfaces? On the other hand, is there a point where, even on rough surfaces, a wider tire is not faster than a narrower one? 60 mm? 70 mm? 100 mm? All this data shows that 31 mm tires roll as fast as 25 mm tires, even on very smooth roads. And when the roads get rougher, the wider tires roll faster. What about even wider tires? Our on-the-road experience suggests that even 42 mm-wide tires do not roll slower than 25 mm tires (above), but without rigorous testing under controlled conditions, we can not say for sure. We hope to test this soon. --http://janheine.wordpress.com/2014/01/01/tires-how-wide-is-too-wide/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance from SCHWALBE
On Saturday, January 4, 2014 12:17:13 PM UTC-8, ted wrote: 3) For a given tire increasing pressure reduces rolling resistance. It depends what you call rolling resistance. If you define it as only the hysteretic losses within the tire, then it's true. However, if you are looking at the OVERALL resistance of the bike, then increasing your tire pressure beyond a certain point doesn't gain anything at all! You just bounce more. So your tire doesn't flex much, but you flex more - the end result is a draw on very smooth roads, and probably a loss on rougher roads. This fact, which is well-documented by now (we ran several tires at pressures from 30 to 200 psi in 10 psi increments), is the reason why wide tires can be fast. If high pressures were faster than lower ones, then you'd have to beef up the casing of wider tires to enable them to run high pressures, and you'd lose all the suppleness. So you'd have a choice of either losing speed due to a sturdy casing, or losing speed because you have to run low pressures. (The load on a wide tire is much greater for the same pressure than it is on a narrow one.) In reality, you can use a supple casing, run your wide tire at relatively low pressures, and you don't lose anything due to the low pressures, but gain due to the supple casing. This finding has revolutionized our understanding of wide tires. No longer is desirable to make wide tires that can handle 100 psi or more - it's in fact counterproductive, since such a strong casing cannot be supple. Of course, none of this is new, it just had been forgotten for a few decades. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance from SCHWALBE
I would rather know how wide is wide enough (as opposed to how wide is too wide). It seems generally accepted that really low pressure results in more rolling resistance than somewhat more pressure does. Somebody (sorry to say I forget the proper citation to credit the appropriate party) did some investigation and concluded that the pressure to achieve 15% drop produced an optimum trade off, with further increases in pressure yielding insignificant reductions in resistance. They then generated curves indicating what pressure was required to produce the chosen 15% drop as a function of load and tire width. If I recall correctly that work presumed that further pressure increases would produce small reductions in resistance but that rider comfort would be compromised and it wasn't worth it to ride harder tires. I think Jan's work shows that (due to suspension losses which he includes in rolling resistance) for real world conditions there will be a true rolling resistance minimum at some optimal pressure for a given combination of road surface, rider, and tire. The point where decreasing losses in the tire itself are offset by increased suspension losses in the rider determining that optimum. I think it is reasonable to postulate that such an optimum pressure would depend on how rough the surface was. I do not know if Jan (or anybody else) has tested that hypothesis.Since narrower tires ride squishier for a given pressure, it also seems likely that such an optimum pressure would be higher for narrower tires. Again I don't know if that hypothesis has ben tested experimentally. The question does tire a roll faster than tire b is not really a properly posed question without some assumption about the tire pressure. If we accept Jan's statements about suspension losses it seems assumptions about the road surface (and perhaps the body composition of the rider) may also be necessary. Are the tires to be compared at equal pressure? At 15% drop? At an experimentally determined optimum pressure for a given load and road surface? I think we all assume such comparisons are made with equal load, and that increasing or decreasing the load would not change the relative rankings of the tires (I don't know if anybody has proven that experimentally). What I would like to know is, for me, using tire pressures I find comfy but not overly squishy, how much faster is a Hetre than a Lierre than a Cypres on different sorts of surfaces. I expect the only way to find out is to buy and ride each type myself, because I doubt anybody is going to publish curves of watts per kph as a function of load and tire pressure on a variety of surfaces for each of those tires (with margin of error / uncertainty too of course). It would sure be nice if somebody did though. On Saturday, January 4, 2014 1:17:58 PM UTC-8, Patrick Moore wrote: IIRC, Jan has asked aloud if there is a point where wider might begin to make a tire slower. Has this been answered? Also, has he or anyone else determined that a 23 mm Pro Race 3 is slower than a 25 mm on a very smooth road? A 19mm? On glass? In brief, is there a breadth below which an otherwise identical tire is always slower even on the best of surfaces? On the other hand, is there a point where, even on rough surfaces, a wider tire is not faster than a narrower one? 60 mm? 70 mm? 100 mm? Will they ride Pugsleys in Paris Roubaix? Patrick Moore, asking seriously despite the flippancy, who does plan to replace his Pro Race 23s with 25s. On Sat, Jan 4, 2014 at 1:17 PM, ted ted@comcast.net javascript:wrote: 2) All other things being equal a wider tire will have lower rolling resistance than a narrower one. -- Burque (NM) Resumes that get interviews: http://www.resumespecialties.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance from SCHWALBE
Um yea Jan, hence the portion of the my original text between resistance and the period: ... (on smooth surface or neglecting suspension losses), but at very low pressure this change is larger than at higher pressures, and as pressure increases the effect becomes negligable. That increasing pressure beyond a certain point increases the linear component of drag doesn't mean that reducing pressure below that point doesn't also increase the linear component of drag. This is just the normal nature of a local optimum. Did you measure lower resistance at 30psi than 40psi using a ~23mm tire? I was told decades ago (by somebody I believed) that, even without suspension losses, a tires rolling resistance as a function of inflation pressure will exhibit a minimum, and I haven't forgotten it. On Saturday, January 4, 2014 4:18:40 PM UTC-8, Jan Heine wrote: On Saturday, January 4, 2014 12:17:13 PM UTC-8, ted wrote: 3) For a given tire increasing pressure reduces rolling resistance. It depends what you call rolling resistance. If you define it as only the hysteretic losses within the tire, then it's true. However, if you are looking at the OVERALL resistance of the bike, then increasing your tire pressure beyond a certain point doesn't gain anything at all! You just bounce more. So your tire doesn't flex much, but you flex more - the end result is a draw on very smooth roads, and probably a loss on rougher roads. This fact, which is well-documented by now (we ran several tires at pressures from 30 to 200 psi in 10 psi increments), is the reason why wide tires can be fast. If high pressures were faster than lower ones, then you'd have to beef up the casing of wider tires to enable them to run high pressures, and you'd lose all the suppleness. So you'd have a choice of either losing speed due to a sturdy casing, or losing speed because you have to run low pressures. (The load on a wide tire is much greater for the same pressure than it is on a narrow one.) In reality, you can use a supple casing, run your wide tire at relatively low pressures, and you don't lose anything due to the low pressures, but gain due to the supple casing. This finding has revolutionized our understanding of wide tires. No longer is desirable to make wide tires that can handle 100 psi or more - it's in fact counterproductive, since such a strong casing cannot be supple. Of course, none of this is new, it just had been forgotten for a few decades. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance from SCHWALBE
Obviously, if your tire is flat, rolling resistance is very high. So there is a minimum pressure below which rolling resistance increases. In our testing, we found that this pressure was about at the point where the tire no longer cornered safely - pretty low! There also must be a maximum pressure beyond which tires become slower. At infinite pressure, the tire would be totally stiff, and then you'd be back to the old days when wheels were shod with narrow strips of rubber. Those were very slow. In reality, the pressures we tend to ride are in the middle - even 200 psi isn't making a tire totally stiff - so we don't need to worry about it. Basically, a Grand Bois 700C x 32 mm (or Vittoria CX Corsa 25 mm) tire is as fast at 60 psi as it is at 200 psi. At moderately high pressures (110 psi or so), they actually were a little slower, but this is a minor effect. While statistically significant (so it's not noise in the data), running your tires at 110 psi will only make you marginally slower than running them at 60 or 80 psi. I am quoting from memory, the exact data is in the *Bicycle Quarterly* article (Vol. 11, No. 3). So for practical purposes, tire pressure should be selected as low as you can go while still getting good cornering. This holds true at least for high-performance tires. We haven't tested this for sturdy, belted utility tires, but if you are concerned about performance, you won't run those, anyhow. Jan Heine Editor Bicycle Quarterly http://www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance from SCHWALBE
Thanks for the information Jan, Some of your comments elicit some questions. You say: a Grand Bois 700C x 32 mm (or Vittoria CX Corsa 25 mm) tire is as fast at 60 psi as it is at 200 psi. At moderately high pressures (110 psi or so), they actually were a little slower, but this is a minor effect. While statistically significant (so it's not noise in the data), running your tires at 110 psi will only make you marginally slower than running them at 60 or 80 psi. Are you equating the behavior of high performance 32mm clinchers and 25mm tubulars, or are both tires you mention clinchers? Are you saying these tires have the same rolling resistance or just that their resistances as functions of pressure have the same derivatives, or just that the curves have vaguely similar shapes, or something else entirely? Are you saying that the optimum pressure for such tires from a rolling resistance standpoint is about 60 or 80 psi, and that the variation in rolling resistance anywhere from 60 to 110 psi, though measurable, is negligible? What was the load on the tire for these measurements? Are the rolling resistances at 60, 70, 80, and 90 psi measurably different? If these tires are as fast at 60psi as they are at 200psi (wording that seems to imply equality), but marginally slower at 110psi, doesn't that imply that they are faster at 200psi than at 110psi (though faster still some where between 60 and 80psi)? Isn't that rather surprising/improbable? Are these tires only as fast at 60psi as they are at 200psi or are they faster at 60 than at 200? Have you ever known anybody to actually use a 32mm bike tire at pressures greater than (or even as high as) 110psi? Is it safe to put 200psi in a grand boise 700c 32mm tire? You also say: ... there is a minimum pressure below which rolling resistance increases. In our testing, we found that this pressure was about at the point where the tire no longer cornered safely - pretty low! Are you saying that for a 32mm tire 60psi is pretty low! and that at pressures lower than 60psi cornering is unsafe? You say: ... moderately high pressures (110 psi or so), Do you really feel that 110psi in a 32mm tire is a moderately high pressure? If you do I am going to have to seriously revise my understanding of every qualitative recommendation of yours that I have ever read. I fear I have been seriously mistaken about what high and low mean. thanks for your help. On Saturday, January 4, 2014 7:26:34 PM UTC-8, Jan Heine wrote: Obviously, if your tire is flat, rolling resistance is very high. So there is a minimum pressure below which rolling resistance increases. In our testing, we found that this pressure was about at the point where the tire no longer cornered safely - pretty low! There also must be a maximum pressure beyond which tires become slower. At infinite pressure, the tire would be totally stiff, and then you'd be back to the old days when wheels were shod with narrow strips of rubber. Those were very slow. In reality, the pressures we tend to ride are in the middle - even 200 psi isn't making a tire totally stiff - so we don't need to worry about it. Basically, a Grand Bois 700C x 32 mm (or Vittoria CX Corsa 25 mm) tire is as fast at 60 psi as it is at 200 psi. At moderately high pressures (110 psi or so), they actually were a little slower, but this is a minor effect. While statistically significant (so it's not noise in the data), running your tires at 110 psi will only make you marginally slower than running them at 60 or 80 psi. I am quoting from memory, the exact data is in the *Bicycle Quarterly* article (Vol. 11, No. 3). So for practical purposes, tire pressure should be selected as low as you can go while still getting good cornering. This holds true at least for high-performance tires. We haven't tested this for sturdy, belted utility tires, but if you are concerned about performance, you won't run those, anyhow. Jan Heine Editor Bicycle Quarterly http://www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance
The way I see it is, there is scientific data that Jan has provided here that works as a good evaluation of performance in a vacuum or for competitive reasons. On the other hand, placebo's work, and are also scientifically commensurable. Bikes feel different loaded up and with different sized tires. Who knows how the body truly reacts to the way different bikes/loads/tires feel, and whether or not your mind, and in turn, body, decide to push harder or not. But every day I'm becoming a stronger rider, loading up with more crap, and always going faster, so I'll never know. On Thursday, January 2, 2014 6:21:53 AM UTC-8, Jan Heine wrote: Even though most RBW folks may not care all that much about going fast, it's still nice to know that a wider tire doesn't roll any slower. We summarized the data in our blog here: http://janheine.wordpress.com/2014/01/01/tires-how-wide-is-too-wide/ If anything, it may help persuade those we meet on our rides, who look at our bikes and are intrigued by the idea of a more comfortable bike with wider tires, but are afraid they won't be able to keep up with their friends if they add 5 or 10 mm to their tire width. Happy New Year! Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance
How about heavier tires , have you done a test with those ? You know ... there's heavy , heavier and really really heavy tires ! Like those 2+ pounders ! lol ;) -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance
again, rolling resistance is contact patch and rubber characteristics (compound, tread). Weight is inertia and is felt in acceleration/deceleration. Weight doesn't hurt you going downhill, as I'm often able to demonstrate - I'm 6'3 and 215 lbs. when lean. On Thursday, January 2, 2014 10:12:02 AM UTC-6, Garth wrote: How about heavier tires , have you done a test with those ? You know ... there's heavy , heavier and really really heavy tires ! Like those 2+ pounders ! lol ;) -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance
Thanks, Jan, always a treat to read your blog posts, for the insights and clear writing. I'm sharing this with several skinny friends who often comment on the girth (ahem) of my tires (33.33mm JackBrowns, both colours, on different bikes). - Andrew, Berkeley On Thursday, January 2, 2014 6:21:53 AM UTC-8, Jan Heine wrote: Even though most RBW folks may not care all that much about going fast, it's still nice to know that a wider tire doesn't roll any slower. We summarized the data in our blog here: http://janheine.wordpress.com/2014/01/01/tires-how-wide-is-too-wide/ If anything, it may help persuade those we meet on our rides, who look at our bikes and are intrigued by the idea of a more comfortable bike with wider tires, but are afraid they won't be able to keep up with their friends if they add 5 or 10 mm to their tire width. Happy New Year! Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at www.janheine.wordpress.com -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance
Too complicated for me ... lol... too many intangibles . I'll just stick to riding :) (When the weather warms up that is ) On Thursday, January 2, 2014 12:41:09 PM UTC-5, Ron Mc wrote: again, rolling resistance is contact patch and rubber characteristics (compound, tread). Weight is inertia and is felt in acceleration/deceleration. Weight doesn't hurt you going downhill, as I'm often able to demonstrate - I'm 6'3 and 215 lbs. when lean. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
[RBW] Re: Tire Width and Performance
Some interesting thoughts here. A few added thoughts: *Contact patch:* We've been thinking about this. We are lucky today to have numerous tires that have the same casing, so at least we can do a controlled experiment. It is good to be able to explain the data, but it's important to note that the data shows that 25 mm tires are faster than 23 mm. No matter how we explain it (contact patch shape, lower suspension losses, better aerodynamics, whatever), the results won't change. *Light wheels and acceleration/climbing:* The math assumes a constant power output, but we know riders have anything but a constant power output. We pedal at 60-120 rpm, and within each stroke, we have a very distinct power phase. Does this change the equation? For frame stiffness, it certainly does. With constant power, frame stiffness wouldn't matter at all, and planing would not exist. I am not saying that lighter wheels climb better (many of my best times on mountain passes have been on 650B x 42 mm tires), but I would like to caution that the simple math may not be the entire story. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance
This is interesting. I climb as much standing as sitting, and always at low rpm, high torque cadences. And it is precisely when I stand that the gofast feels fastest and liveliest. Again, this is consistent over 10+ years. Consistently too, on certain types of rides, for example, often when doing mildly rolling, typical suburban route with many stops and starts and no need to stand except for startups, the gofast often feels slower than other bikes. I do plan to replace the Michelin Pro Race 3 23s with 25s as soon as I get the cash. But the 23s are very supple, as were the old 559X1 Turbos. On Thu, Jan 2, 2014 at 4:26 PM, Jan Heine hein...@earthlink.net wrote: Some interesting thoughts here. A few added thoughts: *Light wheels and acceleration/climbing:* The math assumes a constant power output, but we know riders have anything but a constant power output. We pedal at 60-120 rpm, and within each stroke, we have a very distinct power phase. Does this change the equation? For frame stiffness, it certainly does. With constant power, frame stiffness wouldn't matter at all, and planing would not exist. I am not saying that lighter wheels climb better (many of my best times on mountain passes have been on 650B x 42 mm tires), but I would like to caution that the simple math may not be the entire story. Ja -- Burque (NM) Resumes that get interviews: http://www.resumespecialties.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance
I love, love,love the ProRace3's on my go-fast bike! I just wish I had room under the front fork for a 25. Even the 23 barely fits. it's crazy. And it's a steel fork, go figure. Whoever designed this fork was clearly not very forward thinking. I was looking at replacement forks online with a proper fork crown and clearance for 28s with fenders, or 32s without. Reason I mention the 28 is that the ProRace 2/3/4 25mm tires often measure closer to 28mm installed. On a recent thread on a tandem forum one owner showed a digital caliper measurement of 27.9mm on a 25mm Pro4 Endurance. On Thu, Jan 2, 2014 at 6:02 PM, Patrick Moore bertin...@gmail.com wrote: This is interesting. I climb as much standing as sitting, and always at low rpm, high torque cadences. And it is precisely when I stand that the gofast feels fastest and liveliest. Again, this is consistent over 10+ years. Consistently too, on certain types of rides, for example, often when doing mildly rolling, typical suburban route with many stops and starts and no need to stand except for startups, the gofast often feels slower than other bikes. I do plan to replace the Michelin Pro Race 3 23s with 25s as soon as I get the cash. But the 23s are very supple, as were the old 559X1 Turbos. On Thu, Jan 2, 2014 at 4:26 PM, Jan Heine hein...@earthlink.net wrote: Some interesting thoughts here. A few added thoughts: *Light wheels and acceleration/climbing:* The math assumes a constant power output, but we know riders have anything but a constant power output. We pedal at 60-120 rpm, and within each stroke, we have a very distinct power phase. Does this change the equation? For frame stiffness, it certainly does. With constant power, frame stiffness wouldn't matter at all, and planing would not exist. I am not saying that lighter wheels climb better (many of my best times on mountain passes have been on 650B x 42 mm tires), but I would like to caution that the simple math may not be the entire story. Ja -- Burque (NM) Resumes that get interviews: http://www.resumespecialties.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- Keep the metal side up and the rubber side down! -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
Re: [RBW] Re: Tire Width and Performance
That's good to know; so at least one other person finds them fast. The 650C 23s are really skinny, though -- barely 22 mm on the 19 mm (outside) semi aero rims. The 23s are fine on smooth pavements, and our pavement isn't that bad, at least where I ride, except for the huge expansion cracks due, I guess, to large low-to-high temperature differentials. I have to be careful about those. On Thu, Jan 2, 2014 at 5:25 PM, Jim Bronson jim.bron...@gmail.com wrote: I love, love,love the ProRace3's on my go-fast bike! I just wish I had room under the front fork for a 25. Even the 23 barely fits. it's crazy. And it's a steel fork, go figure. Whoever designed this fork was clearly not very forward thinking. I was looking at replacement forks online with a proper fork crown and clearance for 28s with fenders, or 32s without. Reason I mention the 28 is that the ProRace 2/3/4 25mm tires often measure closer to 28mm installed. On a recent thread on a tandem forum one owner showed a digital caliper measurement of 27.9mm on a 25mm Pro4 Endurance. On Thu, Jan 2, 2014 at 6:02 PM, Patrick Moore bertin...@gmail.com wrote: This is interesting. I climb as much standing as sitting, and always at low rpm, high torque cadences. And it is precisely when I stand that the gofast feels fastest and liveliest. Again, this is consistent over 10+ years. Consistently too, on certain types of rides, for example, often when doing mildly rolling, typical suburban route with many stops and starts and no need to stand except for startups, the gofast often feels slower than other bikes. I do plan to replace the Michelin Pro Race 3 23s with 25s as soon as I get the cash. But the 23s are very supple, as were the old 559X1 Turbos. On Thu, Jan 2, 2014 at 4:26 PM, Jan Heine hein...@earthlink.net wrote: Some interesting thoughts here. A few added thoughts: *Light wheels and acceleration/climbing:* The math assumes a constant power output, but we know riders have anything but a constant power output. We pedal at 60-120 rpm, and within each stroke, we have a very distinct power phase. Does this change the equation? For frame stiffness, it certainly does. With constant power, frame stiffness wouldn't matter at all, and planing would not exist. I am not saying that lighter wheels climb better (many of my best times on mountain passes have been on 650B x 42 mm tires), but I would like to caution that the simple math may not be the entire story. Ja -- Burque (NM) Resumes that get interviews: http://www.resumespecialties.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- Keep the metal side up and the rubber side down! -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out. -- Burque (NM) Resumes that get interviews: http://www.resumespecialties.com/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/groups/opt_out.
