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