Mountain Biking - converting 7 spd to 9
Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
08-22-08, 05:57 PM
I own a older non-suspension TREK mb with shimano deore xt gear. It has 3 x 7 gearing. I was wondering what it would take to convert it to 3 x 9 gearing so I can use the new shimano deore xtr or xt shifter/brake lever combos. I also wanted to convert it to a suspension front fork but that is a different subject. Thanks in advance !! Don
Probably need a new rear hub or rear wheel. 9 speed cassettes are wider than 7 speed so they stick out too far.
08-22-08, 07:50 PM
Yeah you can use the XT XTR shifter but if I'm not mistaken they are for hydros only. You could try the deore integrated ones though. But what you need is shifters, cassete, maybe the new hub, and a new chain.
08-22-08, 09:31 PM
You will not need a new wheel hub. You will need a new freehub to replace the 7speed freehub and you will have to re-dish the wheel to center it after adding the new freehub. You will need a new cassette (of course) and a new chain. Play it safe and check the spacing in your chainwheels to be sure they are spaced tight enough that a 9 speed chain will not slip between the chainwheels. I've been told with some crank/chainwheel set ups, it can happen that a 9 speed chain can slip between the chainwheels, but the 7 speed chainwheel spacing I've run into would not allow this to happen.
BUT before you make these changes, I'd check the stem of your bike to determine if you have a 1 1/8" headset or 1" headset. If it's 1", I don't think I'd invest a bunch of money in the bike because upgrading the fork is going to be a problem. If you're lucky enough to have a 1 1/8 inch headset, then have fun with the changes.
EDIT: I just realized, you might be changing to disc brakes. If you are, then yes, you will need to replace the entire hub, it might be cheaper to replace the entire wheel. If you're not changing the brakes then my original explanation stands.
08-25-08, 09:37 AM
Thanks so much for all your great input. It may be in my best interest ,$$$ wize, to look for another bike with all the new gear I want. Maybe a good used one. Happy Trails to all...
Powered by vBulletin® Version 4.1.12 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.