26-08-13, 02:31 PM
If you use a 10 speed chain on a 9 cassette there is a danger that on changing down from the big chainring to the inside ring the chain may fall inbetween the two rings. This is because 9 speed chains are up to 6.8 mm wide and the 10 speed up to 6.2mm wide. I use 9 and 10 cassettes and buy the correct chain for each cassette.