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Hi all, need some help. I'm running 1x9 with an 11-32 cassette, chain device and xt rear mech. I've set up loads of gears and am pretty competent, but this has got me stumped. All gears work fine except the smallest sprocket, where the chain jumps consistently under almost no pressure. I changed the sprocket, didn't help, changed the cassette and chain, still nothing. Thought it must be the b tense spring, so I changed that. Still no better, so I bought a new (used) mech off here, thinking that must be it, but no, still got the problem.
Everything seems to be aligned as I'd expect it to be, chain is as tight as it can be, mech not bent, b tension is fine. Can I have the same problem on two mechs? Any ideas greatly appreciated.
Thanks
Have you checked/tried another hanger? Could be that and its not always obvious
I haven't, it looks fine, mech is straight but perhaps worth a try (I don't have one unfortunately though!)
Good call carlos. I had avery similar problem and it turned out to br the mech hanger.
Had a look, it looks fine. It's a nicolai argon so the mech hanger is a huge piece of aluminium, 5-6mm thick. Looks flat as it should
Mine does this, and its because my mech is pi55ed - so could be mech and/or hanger.
I'll give a third mech a go, then try a new hanger
Chain too long?
Travel limit screws a bit off? (you mentioned the 'B' tensioner, but not that one)
Take the mech hanger off and put it on a very flat surface, like a kitchen worktop to see if that's bent. Turn it over and try both sides.
in addition to the above, check you have the correct lock-ring fitted, 11t has a smaller diameter than those for 12t, and can prevent the chain seating correctly.
Chain is short, limit screws are fine
Lock ring came with cassette so that should be ok too!
Chainline maybe. Got the recommended number of BB spacers on the driveside?
What connector link are you using? I had an issue using a wipperman connex power link fitted upside down that would cause the chain to skip on the 11t cog.
This might sound a bit daft and obvious but I went through a similar problem....
What type of frame have you got and are you over tightening your QR ?
I have a Lapierre full carbon frame and had suffered the same problem with the bottom sprocket. I found the only way I could solve it was to pull the bottom limit screw almost all the way out. Then when I changed to a 2x10 and even that wouldn't solve the problem. The rear mech was ridiculously out of alignment.
First thing I found is that the rear mech protector they put on the Lapierre's was getting in the way of the rear mech, especially when I changed it to the smaller cage. Whipped that off and big improvement but still not perfect. When I was buggering about swapping hangers etc I suddenly noticed how much the frame flexed when I tightened up the QR... it was enough to mess all the alignment up.
Slackening off the QR (I was being over zealous) has meant I can run everything aligned and the limit screws in a more reasonable position.
If you look at the new Lapierre's they have reduced the mech protector to the size of a thumb nail and gone to a rear maxel.
Connector link is the right way around, it's a clarks but the problem has happened with several chains. I'm going to try yet another mech tonight, if it's not that then almost certainly must be the hanger
It was the lockring which was for 12T, dunno how that happened. Thanks all, especially coatesy