Originally Posted by
gellybellyman
Can the 48/38/28, spec'ed by Shimano to be paired with 8-speed cassettes, work with a 9-speed cassette? I'm looking at an Altus FD-RD to make the system work. Will the 2 teeth difference in both mid and small chainrings matter? TIA!
8 and 9 speed triple cranks and chainrings are so close as to be essentially interchangeable. Same with the front derailleur. I done it plenty of times.
You will need a 9 speed chain to work with the 9 speed cassette.
I assume it goes without saying that you will need 9 speed rear shifter as well.
Also, you can ise an 8 speed RD with a 9 speed shifter and cassette as long as the largest cog is not too big.
Google Park Tools instructions for how to determine the proper chain length.