Originally Posted by
bilalsky
Does a 10 speed crankset work with a 8 speed drivetrain?
Probably, maybe. The wider 8-speed chain may not shift well on the narrower 10-speed rings. When on the small ring, the chain may catch on the back of the bigger ring and jam into the chainstay (aka chain suck).
Originally Posted by
bilalsky
Also if it does then what speed should the chain be?
8-speed chain with an 8-speed cassette. However, you may get away with using a narrower 9-speed chain, which would probably work better with the 10-speed crank than an 8-speed chain.
Originally Posted by
bilalsky
Is a 9 speed derailer compatible with a 8 speed cassette?
Yes. All of Shimano's 8 and 9-speed stuff uses the same SIS standard. The shifter will control the speeds, i.e. an 8-speed shifter will index 8 speeds with a 9-speed rear derailleur.
Originally Posted by
bilalsky
Do all the components have to be the same speed and is it possible for me to mix and match?
All of Shimano's 7, 8, 9 (Road and MTB) and 10-speed (Road only) shifters and rear derailleurs are SIS. The shifter controls the indexed speeds, and works with any of these rear derailleurs.
It's best to match the chain to the cassette, but you can often get away with a chain that's "1 speed off".