I know its probably a slight alignment issue of the mech and hanger but wondered if there was owt i had missed.

Yesterday i really bent the inner plate of the cage on my X9 mech, when i got home i took it off and flattened it in a vice. To the naked eye its looks flat. The hanger is 99% straight.
Gears all change fine but on the bottom cog the jockey wheel skips on each revolution of the wheel.

Is the mech so sensitive that a hanger that is about 1mm out (max) and a nearly straight mech plate would cause this to happen? Its fine in all other sprockets on the cassette, just an issue on the bottom one

Stiff link!

bottom being 11T or 32T?

if former, is it possible the top jockey is too close to the sprocket? Use the B-tension screw to bring it away a bit.

EDIT FOLLOWING POSTIE’s POST: Im assuming when you say wheel revolution you mean it, not chain revolution?

wheel rev – yes

so are you both discounting the slight anomalies in the hanger and inner cage plate?

or do you mean chainring revolution ? – in which case, maybe bent chainring tooth and bigger chain angle to the “end” sprocket ?

r_r – if it happens only once in a revolution OF THE WHEEL then it probably wont be a hanger issue – otherwise it would skip all the time.

A jockey wheel has 10 teeth, and (im assuming here) that your “bottom” sprocket has 11 teeth, so if it’s definitely a wheel revolution (we’re counting on you with this, because there’s lots more possibilities if it’s not a wheel rev 🙂 then my money would be on jockey wheel/cassette issue.

could it be the alignment of the bottom jockey wheel as this has no float and is furthest from and bends so worst affected?

if the cage is still sufficiently bent to bugger up the top jockey wheel alignment then yes.

Given up – i reckon there are too many alignment issues. New mech and hanger will be here by wednesday 🙂

I managed to twist a link on a sram chain the other day, so now I have two power links in it!