We have a CoMo Speedster, purchased used, about a 2004 model - we're not sure. In any case it has the 28.5" BB spacing. It came with Race Face cranksets, 34-44-54 rings, and 175/170 crankarms. The chainrings are too big for us and so are the crankarms. We're both fairly short. I'd like to use the same crankarms as our singles: 170 for captain and 165 for stoker. So my plan is to replace both cranksets. The only thing I can find that's close is FSA Gossamer with 172.5/165 cranks and 30-39-52 rings. We'd like to replace the 30 ring with a 26. That gives us two 13T shifts. The bike came with an Ultegra 9-speed FD with a clamp mount. The bike shifts perfectly now. I'd like to retain that FD, though I've heard that the new 10-speed Ultegras may work better in this application. If we went to a 10-speed FD, do we replace the brifter also?
As long as we're doing this major upgrade, I thought it might be nice to go carbon belt drive, too.
What we're trying to accomplish is to have more comfort and endurance on long rides. I think we'd do better to spin faster in lower gears. Hence the shorter arms and smaller rings.
Thoughts? And thanks!