About six months ago I bought my first road bike, an old Peugeot Nice 12 speed. I got hooked an have already bought a second, a 2009 Bianchi Via Nirone 7.
Anyway, I'm looking to upgrade some parts on the Bianchi, mainly the crankset, and I have a few questions. I'm looking at parts on ebay and see that they are designated as 9 speed, 10 speed, etc. Is there really a need to stick with the correct speed for the cassette I have? If so, why? I'd think that a 9 speed chrankset's cogs would be the same as a 10 speed's, no? I see a ton of 10 speed stuff listed, not so much for the 9 speed that I have.
The biggest difference between the 9 and 10 speed is the thickness of the cogs. In order to fit more gears in, Shimano, SRAM, and Campy made the cogs on their cassettes slightly thinner. In order to make them work well, they also made the chain a little thinner. To accomodate the chain, the chainwheels had to be thinner. It would seem that you could use a the chain rings from a 10-speed crankset in a 9-speed set up but the shifting gets really crappy because the 10-speed chainring's shifting notches and ramps are smaller than what is needed for a 9-speed chain. Maybe you are looking at the wrong section of eBay. I found this: ebay.comi.htmlOpen ↗
