What proportion of the sprocket is the chain wrapped round? If it’s only engaging a few teeth it can easy I’ll jump. Fiddling with chain length and derailleur b screw can fix this.
It can also be caused by a worn chain. How many miles does it have on it?
chain has 1700km on it and has plenty of life left, all cogs are in good order and chain seems to sit well on 11t. I have played around with derailleur adjustment at various times and thought I had the issue solved but under load it skips still.
What proportion of the sprocket is the chain wrapped round? If it’s only engaging a few teeth it can easy I’ll jump. Fiddling with chain length and derailleur b screw can fix this.
It can also be caused by a worn chain. How many miles does it have on it?