jjbod1

A couple months ago I updated my rig with a completely new drive train. XT shifters, front and rear Derailleurs. LX crankset, and a new chain and rear cassette. Bike has worked flawlessly for 2 months. I have not put a ton of miles on the new stuff yet. But during a ride yesterday, My chain dropped off the front small cog 3 times during my ride. Any ideas what would be causing this and how to fix it?? If it means anything, it is still shifting with out a problem, seems to dereail when i hit a few big bumps in the trail. Thanks in advance.

plasticmaam12

One possible scenario could be this: When you installed the shifter, F DER, and, maybe a new cable, You skipped setting up the low limit screw. It hasn't really mattered until now because the cable tension held the F DER in place and prevented it from going further inboard. Now, your cables have stretched (seated, or whatever) a bit, and when you shift into the smallest cog the F DER is moving inwards further than it had been originally. Just an idea. Would be cool if a quarter turn of a screwdriver were the fix for this. No, that would be too easy.
Good luck.

jjbod1

Thanks for the response, let me say this, i am by no means a bike tech. I have been taking my bikes to shops to get fixed for just about everything, but its getting expensive and I want to do the small stuff myself. Which screw is the low limit? And which way do i turn it? CW or CCW?

plasticmaam12

Clockwise is the way to go. But don't go nuts on it . A quarter turn or an eighth of a turn is often all that is needed. The "low limit screw" is marked by an "L" on the F DER. It should be quite visible. Check out a bike shop for further guidance.