Derailleur doesn't move
 

I have Shimano Dura Ace 10 speed with an 11-23 cassette. My derailleur shifts fine going down the cogs from 23-11 and up the cogs from 12-23. The problem is that, unless I have the cable super tight, the derailleur will not move the chain up from the 11 -12 cog after one click of the shifter. With the cable super tight it creates too much tension, and there is not enough slack for the derailleur to drop the chain back down onto the 11 cog.
I've adjusted the "H" and "L" screws to allow the derailleur to move freely. The cable and housing are new. Can't figure this out.....help!

disconnect the cable ? still won't move by pushing it in with your hand ? replace it,


It will? replace cables & housing..



H is outside stroke limit L is inside stop.. nothing more ..

Shop Tool , check of derailleur hanger alignment always a good start











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Welcome to the fun and exciting world of adjusting indexed shifters! When that happens I undo the cable and start all over again. Make sure the cable is attached exactly as designed, tight but not too tight, and try adjusting it again.

The limit screws will only limit the range of the derailleur so it does not exceed the range of the cassette - so set those limits independently of the shifting. If they're not letting the derailleur cover the range of the cassette, obviously that'll cause a problem. But it sounds like you've got this fairly OK, just double-check it's just limiting the derailleur to "not go too far" at the ends of the range.

I think there should be detailed instructions online, on how to adjust your specific derailleur, maybe even a YouTube video? Starting in the center of the cassette, lining up the derailleur so it's dead on, then going through the gears...

One way I've done most of mine is to start with the cable tension quite tight and on the smallest gear (11 cog), with the adjustment barrel most of the way in. While pedaling, turn the adjustment barrel out until your chain wants to start to shift up to the 12 cog, then back it off 1/2 a turn. Then check to see that you can shift up and down through all the gears.

If this behavior began when you replaced the cables and housing, check all that again. It sounds as if there is friction preventing the free release of the cable. FWIW, this can be an indication of a cable fraying inside the shifter, though that's unlikely with your new cables.

Sounds like a friction issue to me. I'd start with my high/low backed all the way out and make sure my cables are loosey-goosey...while you're checking all that perhaps have some lube sprayed on the derr and let it soak in...

Another thing to check is the derailleur hanger alignment. If it is bent the derailleur won't shift properly.

Assuming the cables are ok and the hanger is OK, then watch this:

Also make sure the cable is properly clamped in the RDER.
If it's not a "straight shot", it may be binding.

Problem solved. I lengthened the cable loop at the derailleur. It is quite big, but shifting is now ideal.
https://cimg3.ibsrv.net/gimg/bikefor...16acc30745.jpg

Very true.
I'll bet shifting would be also be ideal if the loop were a bit less lengthy. :)

^^^ yes!

That loop is excessively long. I would be embarrassed to ride that.

A lot of people screw up their shifting wth too short of housing in the rear loop. You’re on the right track.

I think you’ve overdone it. I’m certain you can achieve smooth cable pull on a shorter loop.

If you can’t, I’d suggest a smoother inner cable.

You're surely having a joke, right? I run those lil Avid thingamajigs on a few of my bikes....they work well to largely eliminate that snag-catcher on my off-roady bikes.

I have shortened it, and shifting is still good. I had it extra long just to test if length was the issue.

Excellent!