Originally Posted by
BlazingPedals
I'm not sure I understand what you're saying. It sounds like the justification for the new rim size is that it needs a new frame, too?
No, the deal is that with 650B you can fit wider tires onto an existing road frame, where there wouldn't be clearance for wider 700C tires. The problem with going with too small of a wheel is that you have a limit of about 750 mm from brake bridge to the rim. 650B is therefore a compromise for a conversion of an existing design. You can use any wheel size you want if you design for it.
I have an inkling to try a conversion on my commuter bike.
-Gary