I’ve got a small problem with my 1×9 setup which is effectively relegating me to a 1×6 setup. Basically when I’m climbing steep or short technical climbs and I drop down to the granny gears, it starts to ghost shift. I’ve had it before when the entire range does it a little but it’s the first time I’ve only had it on a couple of gears. What’s the best solution, reindex or a couple of turns on the barrel adjuster?

hardtail or full suspension?

try with the barrel adjuster first. Might be the mech or the hanger is bent. Found in my case that I can get the indexing right (and no ghost shifting) at one end of the cassette or the other. No way to get both. Hanger is slightly twisted from a crash – probably about a mm.

probably indexing, but check for damage to rings, bent or sloppy mech, bent hanger, limit screws, slipping cable, damage to shifter etc etc.

IME, intermittent ghost shifting is most commonly caused by dirt or corrosion somewhere on the cable or outer, most likely at the derailler end.

Endlessly fiddling the alignment with the barrel adjust just moves the problem. Replace the cable and outer, ideally with a continuous outer and rust resistant cable.

Is your cassette and freehub snug? Grab the cassette and see if it wiggles. Also jiggle you cranks to see if there is play in the BB. And look very carefully at the hanger (take it off and lay it on a very flat surface to see if it is perfectly flat). All these can cause chain alignment problems.

Good luck

indexing
mucky cables
bent hanger
worn bearings if it’s a sus bike

Chain line issues?

I set up my 1×9 a few weeks back and had similar problems.

I took the drive side spacer out and put it on the left, effectively moving the chainring inwards and it solved the problem.

On a 1×9 set up, ideally, your chainline should be straight in 5th gear.

It’s a hardtail. Full-length outers that are 3-4 “proper” rides old (probably a dozen including pootling around the city). I’ll check the chainline again tonight first then see where I go.

maybe your cable loop’s too short at the back ?

scardeypants – Doubt it. It’s only just started ghost shifting. First few rides were fine, last two rides were awful and I either had to MTFU up some climbs or walk.