I am afraid that Ian is right. I have measured the circumference of my wife's 700cx28mm wheel and my 650bx42mm (hetre) wheel using the rolling test diagramed in user manual of every cyclometer, and here are the results:
1. 700c wheel with 28mm Clement 28mm tire: 2110mm 2. 650b wheel with 42mm GB Hetres tire: 2094mm The difference is around 1.5cm. If you currently use 170mm or longer crank arms, you can switch to a 165mm crankset and mitigate the drop by 5mm (or a whole 1cm if you use 175mm), but the drop is significant. I hope that's helpful, Franklyn On Wednesday, October 31, 2012 8:33:25 AM UTC-7, IanA wrote: > > 650b rim diameter is 584mm. 700 is 622mm. Not sure that you'd get even > 1cm extra height from the difference in tires. You might be dropping the > BB the best part of 2cm. That's probably pedal strike territory. . > > On Tuesday, October 30, 2012 3:48:33 PM UTC-6, ttoshi wrote: >> >> I'm thinking about a potential 650b Ram with 42mm Hetres. Apparently the >> 42 mm 650b would be equivalent in height to a 28 mm 700c tire, so perhaps >> the BB drop would not be an issue. I'd love to hear if anyone has >> successfully done this. >> >> Thanks, >> Toshi >> >> -- 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/-/H6p6Lo7VORIJ. 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.
