Monday, November 16, 2009

7.5 kg custom single-speed cyclocross





When you remove all the mud, this bike weighs 7.5 kg. Some nontraditional features. Single speed. Campy Record crankset (42 chainring), hs, bb, brake levers, etc. Custom Zipp 32h tubular rear wheel with a DT 240 s hub. Training rear wheel is a Mavic Reflex tubular with a Phil Wood ss hub. I worked with Scott Mares of Sibex Sports to design the geometry. He sends the Cad file to Russia where the thing is CNC'd from titanium and presto you have a frameset. It was fun putting together. TRP says not to use road levers with their brakes, but it works fine. The Zipps are really stiff and light. Excel got the custom drilled 303 cyclocross rim from Zipp and built the wheel. The front wheel is a standard road 303. One thing I discovered the hard way: don't use a 3/32 road chain for single speed cross. They break. So I use thick 3/32 cogs like the Surly or a White Industries freewheel. These are much stouter than road cogs and they work with a 1/8 track chain. This chain works fine with the Record chainring.




There is so much clearance, it has been suggested that I could run it with 29er MTB wheels. May try that over the summer.