my daughter is riding on a new 1400g wheelset, and it made a huge difference in her riding - especially tackling hills - there is no question lighter rims and tires spin up easier
On Sunday, January 5, 2014 10:14:32 AM UTC-6, Tim McNamara wrote: > > Even though I don't recall specific weights being previously mentioned, > it's probably not perceptible. The acceleration of a bicyclist is very low > to the extent that such differences are negligible. Do you notice a > difference in acceleration when your water bottles are full compared to > when they are empty? That difference is 600 gm per 20 oz water bottle, yet > I have never heard anyone complain about two full water bottles slowing > them down. > > Think about rims. Most current high end bike rims are significantly > heavier than they were 40 years ago in the days of 330 and 280 gm rims and > silk tubulars. ~500 gm rims are normal now due to the fad for aero and the > cost-cutting of eliminating spoke nipple ferrules (which requires thicker > rim walls to stave off failure at the spoke holes, resulting in higher rim > weight). No one squawks about how much harder those rims are to > accelerate, even though increased mass in the rim is exactly the same as > increased mass in the tires. Even pro racers use rims that are heavier > than used to be the norm without complaint (mainly due to the beliefs about > aero now being more important than the beliefs about weight, post-Greg > Lemond's victory over Fignon). > > Think about us Riv riders whose bikes tend to be well over 20 lbs before > accessorizing. We tend to poo-poo the weight penalty compared to 15 lb > CFRP bikes as being unimportant. Weight is weight, whether it's on the > tires, the frame, in the saddlebag, in the accessories or on our bellies. > > Indeed, some of the more popular tires in the group have been the Rolly > Polys, Ruffy Tuffys and Jack Browns, Schwalble Marathons, etc., even though > those tires tend towards higher mass (and higher rolling resistance) due to > having thicker rubber tread and being fatter. Fatter tires require more > material and will therefore be heavier than similarly constructed skinnier > tires, and yet we also believe those heavier tires are just as fast or > barely slower on the road because of being wider. > > Our "perceptions" of these things is primarily the result of our beliefs > rather than physics, not unlike the gap between political beliefs and > reality. > > > > On Jan 5, 2014, at 9:15 AM, Ron Mc <bulld...@gmail.com <javascript:>> > wrote: > > no one here has been talking about the difference between a 230g and a > 250g tire. What we're talking about is the difference between a 200g tire > and 500g tire, and it is without question a perceptible difference in > acceleration. > > On Saturday, January 4, 2014 11:52:14 AM UTC-6, Tim McNamara wrote: >> >> Unfortunately there is a boatload of contradictory scientific evidence >> about these sorts of thing. Most of the differences we think we perceive >> are based on the beliefs and assumptions we have about the equipment on our >> bikes, rather than differences we can actually perceive. The felt >> difference in performance between a 230 gm tire and a 250 gm tire is >> primarily placebo effect (whereas the difference between a 230 gm tire and >> an 800 gm tire might fall above the threshold of perceivable difference), >> but many people will adamantly tell you they can clearly feel the >> difference. In a double blind test they couldn't. >> >> I remember a number of years ago when a bike magazine had a bunch of >> otherwise identical steel frames built from a range of tubing from low end >> to high end. When the riders did not know which was which, they couldn't >> tell them apart- yet thousands of published bike reviews have extolled the >> superiority of one tube set over another, claiming dramatic differences in >> performance. Those difference were "perceived" based on the expectations >> of the reviewer. How many time have we read reviews composed of complete >> nonsense like a frame being "stiff yet compliant?" >> >> Tim >> >> >> On Jan 4, 2014, at 7:53 AM, Ron Mc <bulld...@gmail.com> wrote: >> >> Bill, again, I'm telling you it's not a personal thing - it's in our >> wiring to recognize slight changes, especially where work is concerned. We >> don't feel the baseline work, what we feel is the change from the baseline >> work. >> Bike riders feel weight difference in wheels more than anything else, >> because we feel the responsiveness it produces. For racers, total weight, >> aerodynamics (i.e. skinny tires) all add up for the slight edge that may >> nose them ahead by the finish line. But the rest of us know if we have >> light wheels when we start up the hill and we know if we have efficient >> rolling tires when we crest it. >> >> On Friday, January 3, 2014 12:28:45 PM UTC-6, Bill Lindsay wrote: >>> >>> " It's the next subtle increment that we feel. So yes, subtle >>> differences in wheel inertia are more significant to us than adding mass to >>> the bike frame. " >>> >>> and I never once said you can't feel it. If the small difference is a >>> big deal to you, that's perfectly fine. >>> >>> Do lighter wheels spin up faster? Yes! >>> How much faster? A tiny bit faster. >>> Is that tiny bit a big deal to some riders? Absolutely >>> >>> If you can feel the difference and if you like it better then do it. >>> It's great. None of us are racing or timing ourselves. If it feels a lot >>> faster, who cares if it isn't actually measurably a lot faster? If it >>> feels MUCH easier to pedal, who cares if it isn't actually measurably much >>> easier to pedal? >>> >>> Trust me, I'm a tires guy. I've got ~30 pairs of spare tires in my >>> parts bins. Sometimes I run skinnier tires. Why? Because they >>> *feel*different, and sometimes I prefer to do it. I >>> *feel* like it. Sometimes I decide to run 700x25, sometimes 700x28 and >>> sometimes 700x35. They feel different and I run what I feel like running. >>> Feeling is a big deal >>> >>> I remember a similar back and forth when a vendor made a crankset in 170 >>> and 175 and refused to offer it in 172.5mm. He emphatically stated that >>> the reason he wouldn't do it was because it is impossible for a rider to >>> feel the difference between 170 and 172.5. A lot of people (including me) >>> got kind of miffed about it. I sure as heck can feel the difference. >>> Could I get used to a 170? Sure. But I've got 6 bikes and they all have >>> 172.5s. I'm not switching cranks on all my bikes, and I don't want to >>> RE-get-used-to the bike every time I ride it. I can feel the difference >>> and I prefer to run 172.5. I doubt there's a measurable performance >>> benefit, but if somebody told me NOT to run 172.5s because it's impossible >>> to feel the difference, I'd inform them that they are wrong. Similarly, I >>> am not telling you, Ron, NOT to run skinny tires. I'm not telling you >>> whether you can feel it or not. I'm not telling you what you should >>> prefer. If I did any of that I'd be a bigger jerk than I already am. >>> >>> >>> -- >> 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. >> To post to this group, send email to rbw-owne...@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.
