Front derailleur not shifting.

ben@31

After coming off the mtb today my Shimano Deore XT front derailleur won't shift up from the small chainring to the bigger chainring.

My first check was the SLX shifters, to see if the bottom shifter lever was bent up and catching on something. I've had this problem before when we found the bottom shift lever was bent upwards and catching on the upper shift lever, basically trying to change up and down at the same time! However this time the both shift levers move ok. But the tension feels kind of different every time I try them.

Any ideas ? Thanks.

cooldad

It's bent or moved?

The Rookie

So what actually happens? Does the lever move and engage the ratchet and it not shift the chain, or does the lever not work correctly?

kajjal

Try oiling the pivots on the front mech. My road bike stopped shifting consistently and that sorted it after a bit of oil and a few quick shifts.

The Rookie

That usually affects shifting down (spring tension only) not up where the cable will pull it regardless of some friction.

ben@31

The Rookie wrote:

So what actually happens? Does the lever move and engage the ratchet and it not shift the chain, or does the lever not work correctly?

Sorry for the late reply, I got it fixed at a LBS this morning and then was out on the bike.

A closer look this morning found the derailleur wasn't moving at all despite what I did with the shifters. I suspected a snapped cable, I felt the plastic sheath by the handlebars and low and behold could feel nicks and kinks where the handlebars did a 180 during the crash and squished the cable. The LBS found the length of cable under the bottom bracket was just as bad, the strands had all splayed out like a bird cage.

The LBS did a cable swap and away I went. The mechanic said the internal routing in the downtube was a b*sterd. Thanks LBS.