Xt front shifter

[sjbraun]

So I just transformed the drive train on my BMC Monstercross.
XT SL-M780 trigger shifters worked fine when set up yesterday, but today the front shifter doesn't index. I push the lever to shift on to the big chain ring and the shift doesn't hold, the lever just springs back and the chain slips back on to the little chain ring.
I've checked cable tension, it doesn't mater if it's tight or slack.
Any thoughts on what might be happening?

[josephr]

I'd double check your limit settings...maybe not allowing enough pull to engage the indexing gear. Also, double check that you're properly set to double or triple, per your configuration.

[oldpotatoe]

So I just transformed the drive train on my BMC Monstercross.
XT SL-M780 trigger shifters worked fine when set up yesterday, but today the front shifter doesn't index. I push the lever to shift on to the big chain ring and the shift doesn't hold, the lever just springs back and the chain slips back on to the little chain ring.
I've checked cable tension, it doesn't mater if it's tight or slack.
Any thoughts on what might be happening?

As above, may be the upper limit screw is too 'tight' or the shifter is adios..try flushing with WD-40, cable unhooked from front der..these get gummed up or go south just like the road STI do.

[jtbadge]

If your shifter turns out to be dead, I have an SLX SL-M670 10 speed front shifter (for double or triple) that I'd let go super cheap. $15 shipped.