We didn't test the Jack Browns, but we did test the Nifty-Swifty and Maxy-Fasty, which are the same tires, only in 650B. The Nifty-Swifty was about 3% slower. However, compared to other tires, both were among the slower tires we tested, indicating that the casing has a much greater influence on the speed than the tread thickness and extra puncture-proof layer... at least for tires with a relatively stiff casing.
On a supple tire, the puncture-proof layer might slow you down more, simply because it defeats the supple casing. If the casing is already stiff, then adding a stiff layer might not do as much. Jan Heine Editor Bicycle Quarterly www.bikequarterly.com Follow our blog at http://janheine.wordpress.com/ On Friday, May 9, 2014 12:49:40 PM UTC-7, ted wrote: > > If you include the rubber in your definition of casing. I am fairly sure > research has shown that slick tires have less rolling resistance than tires > with a modest tread (I can't speak to the size of the difference though). > Similarly tread compound has been shown to have an impact. > > Tires with light casings tend to have light treads, and vice versa. Jan > may have tested Jack Brown tires in both Blue and Green variants thereby > measuring the effect of the casing reinforcement (as I am not a BQ > subscriber I don't know). Has anybody tested say the BG Rock n' Road and a > tire built with the same casing but a tread more like what the new Compass > tires have? > > It is very hard for me to believe that a thicker heavier layer of tread > doesn't increase the rolling resistance of a tire. I am skeptical about the > notion of a solid center ridge making a thick tread fast. I haven't much > idea if that relates to noise levels at all. > > On Friday, May 9, 2014 11:41:30 AM UTC-7, Cyclofiend Jim wrote: >> >> Most of the analysis of rolling resistance for bicycle tires points at >> casing construction as a much more significant factor WRT rolling >> resistance. You can create sound without all that much energy loss, and >> part of it may be related to the audiological perception of the difference >> - there's a fair bit of tone/timbre difference which certainly fades and we >> also probably get used to over time. But, I'm not sure you find much >> actual friction effect - the deformation of the casing and the ease with >> which that occurs has greater impact (if I'm understanding Jan's tests and >> writings, for example). >> >> - Jim >> > -- 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/d/optout.
