Thursday, March 31, 2016

DIY Split Frame for Belt Drive

   Like a good bottle of wine, or easter candy you took out of your kid's basket, I've been saving this one for a special occasion. Natalie and I were at Cured getting coffee and I spotted this single speed CX commuter converted to belt drive:

Rally Team USA

   You may not know this, but the Raleigh Team USA was not originally set up as a single speed with a belt drive. Crazy, I know. In order to run a belt drive, you have to be able to thread the belt through the rear triangle. This means the frame has to have a break in it. 

Chain line

   Here are some examples of factory frame separations to allow for a belt drive:

On the seat stay

Near the top of the seat stay

On the dropout

   This person must really like this Raleigh, because they built a gap into the frame themselves. They cut the seat stay, and then stuck some kind of rod inside, and then bolted the whole thing back together:

Frame break

Frame Break diagram with bad cropping

They also have a funny home made (maybe?) chain tensioner for the belt:

Chain tensioner

   Would that change the spacing for the rear end? Probably! but the integrity of this bike has already been compromised, and it's steel! It can bend a lot better than carbon. One last parting shot.

   We hung around for a while hoping to talk to the owner, but no one showed up. Good for you, bike customizer! 

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