Im going to be building up a Titus Motolite this winter and want to try and stick with an all Sram drivetrain. Just have a few questions:
If I use a medium cage rear der., can I use three chainrings up front?
How is the quality of the Xgen front der compared to the Shimano XT? Which would you choose and why?
A medium cage can be used on your ML with 3 rings, as there is not much chain stretch on the ML rear suspension.
You need to be aware that you obviously cannot use a 22 front / 11 back, or 44 front / 34 back combos. Keep a sensible chainline and you will be allright.
Use the 1/3 rule on the rear cassette... small ring uses the first inward third of the cassette, the middle ring uses the middle third of the cassette, and the big ring uses the outer third of the cassette.
Long cage can virtually give you access to almost all combos. You decide!
For the front derailleur, the SRAM has some clearance issues for some people where it rubs at some point.
Mine didn't though. I liked my LX front derailleur just as much.
The technical info, to help you decide. I'm not a bike mechanic, so use at your own risk!
A medium cage has a total capacity of 33T, with a limit of 22T front chainring.
A long cage has a total capcity of 45T, with a limit of 22T front chainring.
For the front 44T - 22T = 22T, ok.
Total capacity is the front diff + rear diff.
For a medium cage total capacity is 33T - 22T = 11T left to use in rear.
For a long cage total capacity is 45T - 22T = 23T left to use in rear.
The rear diff is 34T-11T = 23T. Hence a long cage could in theory use the worst gear combo.
So for a medium cage, if you in the 22T ring front you can go from 34T to 23T in rear.
If your in the 44T ring front you can go from 11T to 22T in rear.
If your chainline is on the middle ring (32T), you can go the distance on the rear.
Yes the medium cage will work with triple rings. Just take into account the chain length issues. There's literally dozens on threads discussing this in this forum. As for the front derailleur the X.Gen has clearance issues with some Titus bikes. I don't know about the M-L. I would honestly not recommend this derailleur to anyone unless you're a die hard Sram fan. It does not work any better than shimano, has clearance issue's with a lot of frames and is really heavy for a front derailleur.