I have a 2009 Trek 7.7 FX with Ultegra 12-27T cassette, 50/39/30 Front triple. I want to upgrade the rear cassette to give better hill climbing gears. Can I fit an 11-34 Rear cassette and if so what else needs to change?

1 Answer 1


It depends on your rear derailleur. For 11-34 you will need a long cage one.

  • A triple probably has a long cage derailleur already which has a stated tooth capacity of 40. Your system has (50-30)+(27-12)=35. If you put 11-32 at the rear it would be 41 which might work.
    – Carel
    Apr 24, 2016 at 9:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.