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Not enough cable tension to shift front derailleur

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Not enough cable tension to shift front derailleur

Old 03-19-11, 05:41 PM
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dhoyt
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Not enough cable tension to shift front derailleur

I have mounted the front derailleur perfect, and got all the tension out of the cable. But for some reason the chain will not shift to the high cog.

Any suggestions?
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Old 03-19-11, 06:01 PM
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CACycling
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Without knowing what FD on what bike, I'd recommend:
http://www.parktool.com/blog/repair-...ur-adjustments
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Old 03-19-11, 06:06 PM
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Are you sure that your shifter was in the smallest gear position before attaching the shift cable?

I, of course, would never do such a thing but I know that some of the other guys have done it.
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Old 03-19-11, 06:26 PM
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Originally Posted by Retro Grouch View Post
Are you sure that your shifter was in the smallest gear position before attaching the shift cable?

.
This would only be possible if the stops were adjusted wrong. No cable should equal lowest ring.
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Old 03-19-11, 06:44 PM
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Originally Posted by dvs cycles View Post
This would only be possible if the stops were adjusted wrong. No cable should equal lowest ring.
Shifter, not derailleur.
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Old 03-19-11, 07:33 PM
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Without any more information than given, it could be just about anything.

One of the common causes of difficult front shifting or inability to adjust the front derailleur is misrouting the cable inner wire. It goes over the leverage tab on the derailleur, not under it.



Next, check the limit screws while pulling the exposed inner wire along the down tube by hand.

As others have suggested, make sure the shifter is in the lowest gear when setting the initial cable tension.

Beyond these obvious suggestions, you'll have to supply more information about what is happening (or not happening).
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Old 03-19-11, 07:49 PM
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You say you pulled out all the slack, and yet there isn't enough tension to shift. I interpret that to mean that you didn't get out all the slack, and need to pull more down.

First make sure there's nothing else wrong by trying to shift the FD by pulling the bare wire away from the frame like a bow string. Adjust the outer limit position based on shifting this way. Now use the same technique to adjust the inner limit. Both limits should be set so the FD shifts crisply, but doesn't overshoot and dump the chain.

OK, now that the FD itself it OK, check the shifting using the lever. If it doesn't upshift cleanly you'll need to tighten the cable adjuster if you have one, or pull down more cable (or both).

BTW- it's often hard to pull out all the slack, so stick a pencil into the FD pantograph to push it to the outside somewhat while you're pulling the cable down. Tighten the pinch bolt and you should be good to go. Don't get carried away, though, and pull down too much cable, or it'll hang on the shift to the inner.
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Old 03-19-11, 08:39 PM
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What type of shifters. You need to give a little more info and work on the terminology. Thr front gears are chainrings and the back are cogs.
The der. has two limit screws, an upper and a lower. If the upper is not adjusted properly the der. cannot move far enough to the outside to make the shift. If adjusted too far out the chain will go over the big ring and fall off.
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Old 03-20-11, 04:58 AM
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BTW- it's often hard to pull out all the slack, so stick a pencil into the FD pantograph to push it to the outside somewhat while you're pulling the cable down. Tighten the pinch bolt and you should be good to go. Don't get carried away, though, and pull down too much cable, or it'll hang on the shift to the inner.


I use the pencil trick as well. I have arthritis in my hand & it is like having an extra helper.
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Old 03-20-11, 10:03 AM
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Originally Posted by retro grouch View Post
shifter, not derailleur.
oops.
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