[RBW] Re: Jan Heine says I can ride my Bombadil forever!
I don't know what the big deal is about this issue?! The Bicycle FAQ has a section on rames going soft here: http://www.sheldonbrown.com/brandt/frame-soft.html Good Luck! On Thursday, March 15, 2012 4:05:41 PM UTC-7, Jim wrote: Well, materials science WAS my major, and Jan is right on the bean in my opinion. I have some bike experience to back it up as well, as my pre-riv bike was a fillet-brazed Schwinn that I bought new in 1971, and still have today. No difference in the ride that i can see. The one way a frame COULD get flexier, is if you get a fatigue crack growing in a highly stressed joint, that will increase compliance and ultimately fail completely. So, if you ever do seem to think your bike isn't as stiff as you remember, better do a thorough check of the frame. The issue with leaf springs is that they operate very close to (and sometimes a bit past) the yield strength of the material, and over time and a few potholes you can permanently deform them. Steel bicycle frames don't operate anywhere near yield. Jim in Boulder On Thursday, March 15, 2012 11:25:53 AM UTC-6, William wrote: OK, that's not a direct quote. He didn't say that specifically, but in today's blog post, Jan *does* debunk the notion that steel frames go soft with use. They don't. You can't break in a steel bike and make it get more flexible for comfort and planing, and you can't wear out a steel frame in terms of stiffness. It doesn't get flexier with use. You might break it with use, but you won't make it flexier. Good read and uncontroversial for many of us, but definitely counter to the popular notion in the cycling community in general. http://janheine.wordpress.com/2012/03/15/frames-going-soft/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/xoMdiKZfBMMJ. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Jan Heine says I can ride my Bombadil forever!
So this dude Young... is his Modulus a single or double TT? My unscientific observation is that I've ridden my wife's Stumpy in 1985 and in 2012... I can't feel any difference in how the frame flexes Still rides great. Bobby Materials Science NOT my bag Birmingham On Mar 15, 4:26 pm, William tapebu...@gmail.com wrote: I associate sagging leaf springs with plastic deformation and creep, not a reduction in Young's Modulus. Materials Science wasn't my major, though. The only studies I've seen that show Young's Modulus declining over time is at really high temperatures. On Thursday, March 15, 2012 12:22:37 PM UTC-7, z-man wrote: If that were the case then steel leaf springs would always return to their original shape even after years of use. If Jan were able to to a before and after laser check of his 120,000 mile frame, he might be surprised. RGZ On Thu, Mar 15, 2012 at 12:25 PM, William tapebu...@gmail.com wrote: OK, that's not a direct quote. He didn't say that specifically, but in today's blog post, Jan does debunk the notion that steel frames go soft with use. They don't. You can't break in a steel bike and make it get more flexible for comfort and planing, and you can't wear out a steel frame in terms of stiffness. It doesn't get flexier with use. You might break it with use, but you won't make it flexier. Good read and uncontroversial for many of us, but definitely counter to the popular notion in the cycling community in general. http://janheine.wordpress.com/2012/03/15/frames-going-soft/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/TBsdp3jPkTcJ. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Jan Heine says I can ride my Bombadil forever!
Well, materials science WAS my major, and Jan is right on the bean in my opinion. I have some bike experience to back it up as well, as my pre-riv bike was a fillet-brazed Schwinn that I bought new in 1971, and still have today. No difference in the ride that i can see. The one way a frame COULD get flexier, is if you get a fatigue crack growing in a highly stressed joint, that will increase compliance and ultimately fail completely. So, if you ever do seem to think your bike isn't as stiff as you remember, better do a thorough check of the frame. The issue with leaf springs is that they operate very close to (and sometimes a bit past) the yield strength of the material, and over time and a few potholes you can permanently deform them. Steel bicycle frames don't operate anywhere near yield. Jim in Boulder On Thursday, March 15, 2012 11:25:53 AM UTC-6, William wrote: OK, that's not a direct quote. He didn't say that specifically, but in today's blog post, Jan *does* debunk the notion that steel frames go soft with use. They don't. You can't break in a steel bike and make it get more flexible for comfort and planing, and you can't wear out a steel frame in terms of stiffness. It doesn't get flexier with use. You might break it with use, but you won't make it flexier. Good read and uncontroversial for many of us, but definitely counter to the popular notion in the cycling community in general. http://janheine.wordpress.com/2012/03/15/frames-going-soft/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/AsTAEQ4EBSkJ. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Jan Heine says I can ride my Bombadil forever!
Well, one might not be able to ride one's bombadil forever, but certainly someone or other will be able to ride it forever. It's a bike for multiple geological ages, let alone lifetimes :) On Thursday, March 15, 2012 1:25:53 PM UTC-4, William wrote: OK, that's not a direct quote. He didn't say that specifically, but in today's blog post, Jan *does* debunk the notion that steel frames go soft with use. They don't. You can't break in a steel bike and make it get more flexible for comfort and planing, and you can't wear out a steel frame in terms of stiffness. It doesn't get flexier with use. You might break it with use, but you won't make it flexier. Good read and uncontroversial for many of us, but definitely counter to the popular notion in the cycling community in general. http://janheine.wordpress.com/2012/03/15/frames-going-soft/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/RZXDW9W0PgMJ. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Jan Heine says I can ride my Bombadil forever!
Popping a fresh set of wheels onto an old bike can re-juvenate that new bike snap that Jan mentions. I'm not worried about wearing out my Atlantis in this lifetime. dougP On Mar 15, 4:28 pm, newenglandbike matthiasbe...@gmail.com wrote: Well, one might not be able to ride one's bombadil forever, but certainly someone or other will be able to ride it forever. It's a bike for multiple geological ages, let alone lifetimes :) On Thursday, March 15, 2012 1:25:53 PM UTC-4, William wrote: OK, that's not a direct quote. He didn't say that specifically, but in today's blog post, Jan *does* debunk the notion that steel frames go soft with use. They don't. You can't break in a steel bike and make it get more flexible for comfort and planing, and you can't wear out a steel frame in terms of stiffness. It doesn't get flexier with use. You might break it with use, but you won't make it flexier. Good read and uncontroversial for many of us, but definitely counter to the popular notion in the cycling community in general. http://janheine.wordpress.com/2012/03/15/frames-going-soft/- Hide quoted text - - Show quoted text - -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Jan Heine says I can ride my Bombadil forever!
On Thursday, March 15, 2012 7:05:41 PM UTC-4, Jim wrote: Well, materials science WAS my major, and Jan is right on the bean in my opinion. I have some bike experience to back it up as well, as my pre-riv bike was a fillet-brazed Schwinn that I bought new in 1971, and still have today. No difference in the ride that i can see. The one way a frame COULD get flexier, is if you get a fatigue crack growing in a highly stressed joint, that will increase compliance and ultimately fail completely. So, if you ever do seem to think your bike isn't as stiff as you remember, better do a thorough check of the frame. The issue with leaf springs is that they operate very close to (and sometimes a bit past) the yield strength of the material, and over time and a few potholes you can permanently deform them. Steel bicycle frames don't operate anywhere near yield. Jim in Boulder Not in 'materials science', but grad work in structural geology, and engineering geology, a lot of what we dealt with was in rock deformation (albeit not metal), stress versus strain, plastic deformation versus elastic deformation, tensile strength, etc.; my father was the one who was the machinist (and, aside from bicycles, another hobby of mine is dealing w/ rebuilding old Rovers, which involves working over sheet aluminum, annealing it, etc.), and also taught me a lot. With steel, there's an amount that you can bend it, within the elastic range, where it'll snap back. It can do this repeatedly, over and over. It's when you pass that point, into plastic deformation, that it won't recover. Aluminum, moves from elastic to plastic with much less movement; it's more 'brittle', or, sometimes described as fatigue. Steel, if you don't take it into the plastic range, just keep it within the elastic zone, and it'll remain flexible, and pretty much unphased. Steel tubing is designed to prevent the plastic deformation. Chromoly is alloyed to improve the modulus of elasticity, which would be into Jim's field. Anywho... if it's a good steel alloy, without any manufacturing defects, competently formed into appropriate tubing, skillfully assembled into a frame, and is painted/protected from corrosion, not neglected or left out in the rain for years on end, doesn't suffer any accidents that dent the tubing, well, it should be just fine -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/9amibSfAS5gJ. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
[RBW] Re: Jan Heine says I can ride my Bombadil forever!
Creep can be a cause of plastic deformation, but it tends to make materials stiffer through a mechanism called dislocation pile-up. If that is happening in a steel frame, it should become stiffer over time, not flexier. Of course, if there are micro-cracks, then material strength is less relevant, as the cracks can make the frame seem flexy. On Mar 15, 3:26 pm, William tapebu...@gmail.com wrote: I associate sagging leaf springs with plastic deformation and creep, not a reduction in Young's Modulus. Materials Science wasn't my major, though. The only studies I've seen that show Young's Modulus declining over time is at really high temperatures. On Thursday, March 15, 2012 12:22:37 PM UTC-7, z-man wrote: If that were the case then steel leaf springs would always return to their original shape even after years of use. If Jan were able to to a before and after laser check of his 120,000 mile frame, he might be surprised. RGZ On Thu, Mar 15, 2012 at 12:25 PM, William tapebu...@gmail.com wrote: OK, that's not a direct quote. He didn't say that specifically, but in today's blog post, Jan does debunk the notion that steel frames go soft with use. They don't. You can't break in a steel bike and make it get more flexible for comfort and planing, and you can't wear out a steel frame in terms of stiffness. It doesn't get flexier with use. You might break it with use, but you won't make it flexier. Good read and uncontroversial for many of us, but definitely counter to the popular notion in the cycling community in general. http://janheine.wordpress.com/2012/03/15/frames-going-soft/ -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/TBsdp3jPkTcJ. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
