Have an issue with the drivetrain on my hardtail.
It skips on the 3rd smallest cog (15t), even without much pedalling force. All other gears are fine.
It's a 1x10 setup.
Things I have tried to fix it:
Replaced chain, chainring and cassette with new ones
Done the indexing from scratch
Straightened the derailleur hanger vertically and horizontally with the proper tool
Took the freehub off for a look - all pawls working OK, well greased etc
Checked that the 3rd cog is the right way round!
Any other suggestions for things that could be causing this?
Hmm. Tricky. I had this on a bike I built, used cassette but new chain and new chainring. Skipping just on one cog, but using a slightly used chain sorted it. But as you've got all new stuff, it can't be that.
Stiff link in the chain?
Has third cog got the correct plastic spacer?
How worn are the jockey wheels/ how much play in the rear mech?
Other than that, I'm stumped!
Well, did some more investigating
Took cassette off to check spacers etc - all fine
Checked for stiff links in chain / faulty powerlink
Neither of these fixed it, so I found most of another 10spd mech in the box of bits, and put the backplate and jockey wheels off current one on.
....and I think this has fixed it. Skipping was much reduced on test ride, and with a little fiddling of cable tension the skipping now seems to be gone. Bit weird it did it at first, especially when it was shifting perfectly in the stand.
I'll take that as a win. Probably find a crack in the chainstays or something soon X
My immediate thought was a shifting setup issue, with the chain shifting on and off the 3rd cog. You probably accidentally fixed it with the mech swap. It would also be wise to get a mech hanger aligner to check it's perfectly straight, it's getting more critical now people are running huge 50t cassettes compared to the old standard 11-32.
My 2c - had this with a bent cage on the mech and knackered bearings in the top jockey wheel. Both on SRAM - one GX (jockey wheel), on X01 (bent cage)
Check the cable too