This is driving me nuts, had a Cotic Soul with XT on it since last summer, it’s been perfect for everything i have thrown at it, it’s now started to suck it’s chain like a mad chain sucky thing, it does not actually jam, it just picks the chain up at the sligtest sign of pressure in the inner ring.

I know it’s not a bike specific thing, more a drive train thing, it’s got XT on it that was new 8 months ago, i have just put a new chain on it thinking it was that but to no avail, it still does it in the inner ring, could it be a worn inner ring ?

Its driving me sodding nuts……

Try a new inner ring, that solved mine for a few months anyway. Drivetrain has started slipping a bit now and looking at the rear cassette I think that could be the problem. Lasted 18 months though which I suppose isn’t too bad.

It may be that there’s a deformity on one of the rings grabbing the chain, or a mis-shapen tooth. If you find it try re-shaping it with a file.

Stick bike in a stand, slowly rotate cranks, see if the chain is sticking or lifting on the chainring. Pieface is spot on, it might just be one tooth catching the chain or it might be the whole ring is worn.

mine did it like mad too, especially when mudded up, got remarkably good at back pedaling clipped in!!
be worth checking chain tension too, i’d not shortened my chain when i went from tripple to double! apparantly can make a big difference, as can rear mech spring tension,
my old m750 xt rear mech had gone very light on the spring, but being a cheapo that i am i popped the spring out, snipped a couple of coils off it and reshaped it so it regained the tension!!

It may be that there’s a deformity on one of the rings grabbing the chain, or a mis-shapen tooth. If you find it try re-shaping it with a file.

Never thought about looking for a dodgy tooth.

That actually makes sense as i look down at the rear mech cage when pedalling it seems to be getting tension in the system then releasing it so it could be a dodgy tooth holding onto the chain.

Will order another one just in case, cheers….

snipped a couple of coils off it and reshaped it so it regained the tension

did that work? if so, that’s genius

I had the same problem a few years ago and tried to find a worn spot on my ’07 LX chainset with no luck – it was all worn.

Solution – replaced stock LX middle chainring with a TA chainring.

Bit of an expensive solution – but that chainring is still trucking along today!

brakes,
worked a treat! mech still going and shifting Sweet! i did think at the time am i just beeing a tight 4rse lol! but did the job and has lasted for a good 2 years since before being resigned for a newer model!!