gear indexing

mattmaximus

So it turns out a whole lot of tinkering, youtube watching and swearing isn't the same as really understanding what you're doing...

I've read the various guides on gear indexing and tried to follow instructions but have ended up with a situation where I've got 6 or 7 gears that run fine and the other 3/4 have a variety of issues ranging from a gently yet annoying rattle to jumping up a gear to missing out a sprocket altogether. I'm sure I've got the thing a whole gear out because the chain gets to the top of the cassette (biggest sprocket) a shift early, i.e. there is still another shift left in the levers (which happily doesn't shove the chain onto the wheel, so the limit screws seem to be properly done at least :shock: ) and it takes two shifts to move it off that sprocket.

Is there a way of resetting the whole thing and starting from scratch? The barrel adjuster at the rear mech has gone very stiff and I'm concerned that I've messed it up with excess tinkering.

Any thoughts very welcome. In case it's relevant I'm running sram force throughout and probably not helping matters by swapping over between two sets of wheels.

Thanks

nicklouse

read the quide on Parktools. and start at the beginning.

drlodge

mattmaximus wrote:

So it turns out a whole lot of tinkering, youtube watching and swearing isn't the same as really understanding what you're doing...

I've read the various guides on gear indexing and tried to follow instructions but have ended up with a situation where I've got 6 or 7 gears that run fine and the other 3/4 have a variety of issues ranging from a gently yet annoying rattle to jumping up a gear to missing out a sprocket altogether. I'm sure I've got the thing a whole gear out because the chain gets to the top of the cassette (biggest sprocket) a shift early, i.e. there is still another shift left in the levers (which happily doesn't shove the chain onto the wheel, so the limit screws seem to be properly done at least :shock: ) and it takes two shifts to move it off that sprocket.

Is there a way of resetting the whole thing and starting from scratch? The barrel adjuster at the rear mech has gone very stiff and I'm concerned that I've messed it up with excess tinkering.

Any thoughts very welcome. In case it's relevant I'm running sram force throughout and probably not helping matters by swapping over between two sets of wheels.

Thanks

My advice would be to take the chain off, then by rotating the rear derailleur you can see exactly how the upper jockey wheel lines up with each sprocket as you ratchet through the gears. You can then see which sprockets are lining up perfectly, and if any are not lining up. If some don't then at least you know there is some kind of problem and you can either try and rectify the problem, or find the best possible compromise. For example, you may find that the rear derailleur is not hanging quite straight and the rear hanger is bent.

mattmaximus

okay, fixed now. having put the bike on a stand I could get a better view and there's a little channel on the rear mech just after the barrel adjuster which the gear cable wasn't going into. Once the cable was seated properly it was easy to index the gears.

Thanks for the replies.