Sunday, January 29th, 2012
This may seem like deja vu all over again, but belt drive fever continues with this single speed MTB for Dawson. It all started with a lovely Phil hub with belt-drive single speed cog – the challenge was to build a bike around it. And here it is:
He’s running a SID fork, Avid Elixir brakes, and a 39/24 ratio.
The tricky thing about single speed belt drives, as discussed before, is that you have to be pretty certain about what gear ratio you want. I have to calculate the precise chainstay length based on the front sprocket, rear cog, and belt length – unlike a chain, you can’t just add or subtract a link; there are a finite number of belt lengths available. Fortunately Dawson is an experienced single-speeder so he knew what he was looking for. As with Matt’s Alfine belt drive, we used the Paragon sliding dropouts with the frame-break option. This makes assembly very straightforward, and provides an integrated tensioner which makes setup a snap. Here are some pictures of the frame in progress. The tubing is True Temper OX Platinum, with Columbus Zona seat stays.
Next up: Bobby’s S3 club racer, Mike’s rando ride, and another Bobby’s re-imagined Rhygin!