Wednesday, June 17, 2009

650B Conversion Rolls Forward

The next stage in the life of the Schwinn Le Tour II project is an attempt to convert it to a 650B "country bike." I don't know if it's doable, but I've made a real attempt to start it, rather than only talking about it.

Today I took possession of a set of low-end 650B wheels (Deore M530), ordered through the Re-Cycle Bike Shop. Mike, the mechanic and owner, is spreading the frame to better accommodate the extra width of the new wheels, as well as checking the spoke tension on the new wheels.

I was amazed as just how small the wheels looked in the Le Tour II frame when he had it up on the work stand. There's an amazing gap between where the existing center pull brake shoes are and where they need to be. Going from a 27 inch wheel to the 650B is quite a jump. According to Sheldon Brown, the 27 inch is ISO 630mm and the 650B is ISO 584mm, making the distance difference half of 46mm, or 23mm.

I ordered some Tektro 556 extra long reach brakes and some 650B x 38m tires. I'm hoping that with the new brakes and tires, I'll be able to get the 650B on the road for a test ride within a week.

Possible complicating issues might be:
  • brake mounting compatibility
  • lower drop on the frame might make existing cranks too long
  • cabling is different from center pull to side pull brakes
  • not entirely certain I've got all the clearances I need with 38mm tires
  • might need new brake levers if new brakes require more cable to be pulled
As usual, I welcome your comments, hints, advice, and gotchas in this endeavor. I'll try to get some pics up later.


RD said...

you should make it a single speed :D

Scott Redd said...

I give up. You win. Single speed it is.