Replacement parts on trek 7.5 fx disk

harryracer Posts: 4
edited May 2014 in Workshop
Hi, I have a 7 year old trek 7.5 fx hybrid bike that is in need of some serious maintenance as I haven't used the bike for the past 2 years. Having recently got the bug again it has come apparent that a lot of parts needs replacing of which I want to do myself.
Its spec is currently


Shimano M443 Octalink 48/36/26


SRAM PG950 11-26, 9 speed

Im still happy with the current 9 speed so was looking at currently replacing the cassette and chain and will replace the crank later.

Im looking at having a Shimano Ultegra Hollowtec II triple but in order to use this can I still put in a 9 speed cassette and chain and if so which ones do I look for? I thought 9 speed would all be the same and chain as standard? Not sure just what is supposed to go with what?

My gears Shimano Deore 9 speed that work fine so dont want to mess with this beast just yet.

Any advice would be welcome