I want to upgrade my 2008 Felt z25 roadbike to SRAM Force 22. In buying the new group I need to choose between GXP and BB30 for the crankset. Also for the bottom bracket I need to choose BB30' GXP, pressfit Bb86, pressfit 30. How do I determine what is compatible with my frame. Thanks

If Bikepedia is to be trusted, you have a regular BSA-style BB shell, so you'll need the GXP version, with a GXP BB to match.

HTH
-rob

Why not just call Felt tech support?

Thanks. I should have also added that crankset is shimano 50/34 if thats relevant

More relevant is that it apparently came with a hollowtechII bb, which would indicate that it's a regular threaded BSA BB. 2008? Yeah, that makes sense. Cannoindale started that BB30 nonsense in 2000, but not a whole lot of manufacturers were using it yet in 2008, as far as I recall. Anyway, if it's a 2008 and it's got shimano cranks, you can rest assured you got a "brit" bb shell, and the gxp is your only option, out of those listed in the OP.

I had nothing but problems with my bb30. It squeaked and squawked and no amount of loctite would get rid of the sound. I converted to shimano outbearing with a FSA conversion, and absolutely no problems.