Originally Posted by
Kontact
No. You need a 10 speed cassette with your 10 speed shifter. 10 speed shifters move the derailleur the right amount of distance for 10 speed cassette spacing and won't shift anything but 10 speed cassettes correctly. 8 and 9 speed cassettes have more space between cogs.
Correct. I was thinking RD compatibility and incorrectly included shifters and cassettes as well.