How to figure out which Park Tool to use to remove cassette?

[GolGotha]

Hi guys,

I bought a pre-built bike without any real details as to what pieces were used to make up the bike. Now I'd like to remove the cassette, but don't know what kind of tool I need to buy. Can you guys give me some feedback as to how I can figure out which tool I need to remove my cassette? Thanks.

[Joe_W]

First, figure out whether it is really a cassette you are looking at our a freewheel.
http://sheldonbrown.com/k7.html
Then try to make out any markings on the sprockets maybe find out the brand.
If it is a Shimano compatible cassette then it is easy, use eg. the FR-5G

[Bill]

Also if you are still in doubt, try uploading a picture of it. If you can if not no problem.

[RobAR]

Joe is spot-on with the Park FR-5G suggestion if you are certain that it is, indeed, a cassette.
Joe did, however, omit one itsy-bitsy detail ( I might have done the same, Joe )... there are still a small number of bikes being built with solid rear axles (non-Quick Release, or Bolt-On) that require an FR-5. The 'G' suffix means that it has a Guide that slides into a hollow axle (for QR).
That tool will fit 99% of the cassettes out there - be they Shimano, SRAM, SunTour, SunRace, Chris King, Real or generic stuff. It also fits Shimano disc brake lockrings.

On the off-chance that you have a Campagnolo cassette in the Record, Chorus, Centaur or Athena groups, you'll need a BBT-5 or FR-11C by Park Tools. I can't recall the last time, though, that I saw anything Campy that wasn't QR.