I've done this (or at least attempted this) with an old VooDoo frame that I tried to convert to 700c. I was using Paul's MotoBMX, which has greater travel range than the Motolites, because the brake arms lack the cutaway close to the cable clamp (so the arms are a little heavier). My takeaway was that even though you can place the pads correctly on those long brake arms, you lose so much mechanical advantage in a 26"-to-700c conversion that it's not worth the effort, and it's a waste of pricy brakes.
I still did the conversion, but I used a 700c CX fork and a Mavic Caliper Adjuster in the back - a sort of mid-00s brake boosterish bracket that mounts on the normal 26" studs, with a second set of studs brazed on in 700c position. I went to 16 different Mavic dealers in the East Bay before finding one; every single one of them looked at me as if I was crazy (*WTF are you talking about? Why would anybody want that?*), until I walked into Montano Velo in Oakland, made my lhopeless little speech for the 17th time, and the kid behind the counter said, "oh, you mean THESE?", and pulled a cardboard box with *six* of them out. Using the MotoBMXes with the studs placed in 700c position gave me back the same brake power I would have had with 26" wheels. My guess is that 26"-to-700c was a bridge too far. You might be able to get away with 650B wheels, if you set the brakes tight enough to address the reduction in mechanical advantage. The bigger concern would be the fork; be sure the brake strength is enough, or maybe swap in a 650B fork. Peter Adler Berkeley, CA/USA -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/a5f4cbf4-6a20-49e3-9780-8f35967820c9%40googlegroups.com.
