Joined: Jul 2015
Posts: 7,386
Likes: 3,227
From: NW Oregon
Bikes: 1982 Trek 930R Custom, '91 Diamondback Ascent w/ XT, XTR updates, Fuji Team Pro CF road flyer, Specialized Sirrus Gravel Convert, '09 Comencal Meta 5.5 XC, '02 Marin MBX500, '84 Gitane Criterium bike
going from 50 to 54 front will require a longer chain... reducing from 11-28 to 11-25 in rear will not. doing both changes at once MAY require a longer chain length, dependent on how tightly the original chain length was set. You may possibly need a long caged derailleur, if you maintain the 11-28 in the back, then add the 54 in the front...
Last edited by maddog34; 03-13-17 at 04:26 PM.