Hot on the success of my last post, I'm looking at replacing my shifters - can get a good deal on the new 10 speed deore rapid fire shifters, will they index on my 8 speed cassette? (obviously there will be spare clicks!)
No. The 10 speed cogs are closer together. Furthermore the 7/8/9 mechs have different movement per mm of cable pull to 10 speed. If you want a 10 speed rear you need new mechs and shifters.
