Had this problem a couple of years ago and ended up replacing the whole wheel! Now it’s started again on healthy wheel with new hub plus new cassette/chain/rings. Really doing my head in now as it means no riding once again.

Set rear mech up from scratch plus fiddled with all screws and barrel etc. Can’t get it to work whatever I do.

Any ideas?

Ta

Bent hanger?

Nah, meant to say that in OP.

which do you mean by 2,3,4 – big sprockets or little (I’m assuming big – and they’re the ones that wear quick IME)

when you say “new” drivetrain, are they all the same age and used together? How many miles ?

Check the cable is clamped correctly at the mech

I’d always at least clean the cables (in & out) and preferably replace if I was having gear problems

A bit of front barrel mongery appears to have done the trick. It might now be compensating for any other abnormal adjustments I’ve made at the back, but at least it’s happily working.

2, 3 and 4 as in big sprockets. Driverptrain completely new.

We had this the other day.

Turned out to be a stiff link, much to my chagrin…..

http://singletrackworld.com/forum/topic/indexing-out-on-half-the-cassette

Yeah, I posted on that thread the other day cos I’d experienced the same on another wheel. Didn’t realise at the time I’d see it again on another wheel two days later! Bikes are weird at times.