Rob Perks wrote: > > The volume of air that affects rolling resistance is the cross section > of air directly above the area of deformation. Therefore it stands to > reason that wheel diameter should not play into that. > > It is, so they say -- I am not an engineer -- the contact patch (a sign of which is that tire suppleness affects rolling resistance greatly, indicating that it is the contact patch and not just air volume) that, all else equal, determines rolling resistance, and that is certainly affected by wheel diameter.
Snip. >WRT to smaller wheels and faster acceleration, I have ridden 26" - 29" >with all sorts of tires and still feel that the greates factor >affecting acceleration is the weight not as much the diameter. e. Not quite, I think. First, it is indeed the smaller size that makes smaller wheels so light. You save 100 grams or so at the circumference on the rim and 50 more on the tire, ceteris paribus -- my Sun M14A 559s weigh 360 gr (and are strong enough that I had no problems at all off road) and the 559 Turbos and Conti GPs weigh just under 200 gr. And then add the cumulative effect of taking a bit over an inch off each spoke. My old Ultegra/nothing special 8-9 sp 559 wheelset weighed about 1500 grams with rim tape, no skewers or cassette. Second, most of that weight is at the circumference and we all remember the Law of Moments. Again, riding fixed, you can certainly feel the difference. -- 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-bu...@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.
