Steve, Thanks for catching my brain fart. Of course, the 16mm circumference difference becomes 2.5mm delta in radius. I think this is about right.
best, Franklyn On Wednesday, October 31, 2012 8:52:24 AM UTC-7, Steve Palincsar wrote: > > On Wed, 2012-10-31 at 08:47 -0700, franklyn wrote: > > 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. > > > So if the circumference is 16mm smaller, the difference in diameter will > be 2.55 mm less (dividing the difference by pi); but diameter is not > what's significant here, it's radius, i.e., half the diameter, and the > difference in radius is 1.2mm -- hardly 'significant'. > > > > > > > -- 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/-/Br8xbNBQmQIJ. 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.
