xtr der jumping around
prob here - my friend phoned me and said he is goin bald tryn to fgger this out
xtr rr der - jumps around between two middle cogs
alrdy replcd shifters, cable, wires, cassette, rear hanger - checked alignment
i havnt seen it yet but phaps yall kin help with sum suggestions
It may be possible that the hanger may be out of true. Mech might of received a knock, bending it inwards causing shift problems.
From looking behind the cage should be dead straight inline with all the cassette cogs.
Hope this helps.
Are you talking about ghost or auto shifting where the RD can't decide which cog it's on?
Usually, if the hanger is square, and it isn't a simple trim adjustment, it's a cable problem of some sort. If the cables don't cleanly transmit the position of the lever to the RD, you get sloppy or ghost shifting.
First check that the cable returns crisply on upshifts (towards slack cable) which depend on the low RD return spring tension. From a middle cog upshift one position and note the trim, then sharply pluck the bare cable away from the frame and see if the trim changed. If it did, it was because the cable hung up somewhere and the added tension of the pluck pulled more down. Now backtrack and locate the source of the extra friction. Possibilities include too thick a lube in the housing, frayed or kinked wire, kinked housing, housing pinching down and closing at the base of the ferrule, bad seating of a ferrule, etc.
If it isn't a cable hangup problem, there might still be changes in cable position as things move. If you have one of those cable donuts handy, remove the wire from the RD and slide one between the adjuster and cinch bolt. shift into the problem gear and push the donut up to where the cable emerges from the adjuster or housing stop. Ride normally, or tweak steering & suspension (don't pluck the wire) without shifting. If afterwards the donut is moved down a bit, some movement probably at housing stops changed the cable position and it's time to be a detective again.
These ghost shifting problems are a real pain in the adz, but can be resolved with careful detective work, pinning the problem to a likely area then tracking down the exact cause.
Good luck, let the folks here know if you figure it out.
BTW- you mentioned replacing the cassette but not the chain. Since it didn't make a difference, re-install the old cassette and save the new one until you also replace the chain, otherwise you won't get full value from the new cassette.
The key to solving any problem is to understand and address the underlying cause.