I cannot for the life in me get the shifting/indexing right on my planetx xls.
On the stand I can get the gears working smoothly, but when I take it for a test ride the rear mech will refuse to drop into the smallest cog. I have tried all I can think of.

-3 sets of new inner and outer cables
-limit screws are set correctly, the chain happily drops into the smallest gear without the cable installed.
-the cassette and chain are new, both SRAM
-rival 22 shifters and x9 mech, both are 1-1 actuation
-there are no tight bends or pinch points in the cable run

Any ideas, I have only had this problem with worn bits before, never with all new bits. I can’t see what else to try…. Help

My guess is the rear mech, was a well documented problem at one time.

X9 9-speed is kind of famous for that, not sure if it affects others- the spring slackens over time so it doesn’t pull “out” effectively. Leaving it parked in the smallest gear makes a big difference, daft as it sounds- if I leave my commuter in top gear it’ll shift properly the next day, if I don’t it won’t.

Though “check mech hanger” applies for absolutely all shifting issues, I check bikes every time I have a wheel out just as a matter of habit and except with those with monster dropouts, most of the time they’re a bit bent.

Either that or it’s the b-screw, nobody understands the b-screw.

Is it 10 speed ?

Thanks for the replies.
-replaced the mech hanger for a new one.
-adjusted the b screw
-the shifters are 11s, the mech is 10s but both are 1-1 actuation and after googling people run them without issue.

I still suspect the mech, but don’t expect the hanger to be straight juust because it’s new, we have a hell of a lot of brand new bikes through our workshop, and i’m reckoning about 95% have hangers bent to some degree, and a high percentage of replacements need attention too.

Would it worth trying to shim out the rear mech on the hanger a little and then only adjust the large sprocket limit screw, leaving the other one as it is?

I returned my SRAM X9 10 speed gearset after problems (went with Shimano after that). There was something not right with the rear derailleur. The issue was resistance when trying to change down from the largest sprocket or down into the smallest sprocket.

It was as if the derailleur was being made to move too far and it was sticking at either end. You could actually see the angle of the parallelogram meant the spring was pulling it against itself, as opposed to pulling it sideways, and at the other extreme, the spring wasn’t strong enough.

And you could feel this with the bike up on a stand without a chain fitted by moving the derailleur by pulling on the cable.

It was all very weird. Never got to the bottom of it.

Bit of a late reply, but I think bigyinn has it. Shimmed the mech out 1mm from the hanger and the shifting feels good on the shakedown/carpark spin.
Thanks for the help folks