Originally Posted by
Darth Lefty
Rear derailleurs are compatible through road 10 and mountain 9 so you should be good to go with just the cassette. Watch out for your chain length, since the cassette is bigger you might need a new chain with more links.
Dear Darth, Thanks for your advice, finally I leave my old derailleur Deore XT with a 9V 11-34 cassette and a new chain. however I'm not sure if this cassette would be the one I want in the extent to which that it could affect my performance and speed as I used a 11-28 better for road. anyway I'll try this new one to see what happen. if you have any comment about this, please let me know.
Cheers.