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Old 07-04-05, 08:31 PM   #1
Booger
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Couple quick questions from a newbie...

1) I noticed that the chain rubs the derailer in gears 1-3, but when I adjust it (using the top screw closest to the frame), the chain starts to rub in the higher gears. Is there a way to alleviate all the friction? It doesn't seem possible the way things are setup now.

2) There are 2 adjustment screws on top of the derailer. The one closest to the frame obviously moves the derailer laterally. What's the 2nd one for?

My bike:
KHS Flite 750
Ultegra Derailers

ETA: I did find this article at Sheldon Brown. Very helpful.

Last edited by Booger; 07-04-05 at 09:04 PM.
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Old 07-04-05, 09:03 PM   #2
Devious Golden
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It's a process to get it right, but it makes it easier to take it step by step.

First, I make sure the cage is aligned parallel to the outside chainwheel. You can do this by physically pulling the cable with your hand, and eyeing the outside edge of the derailleur cage to see if it's reasonably parallel. Make sure it has at least a 1 mm clearance over the outside chainwheel also. You may be able to skip these steps.

Now we'll set the inside limit screw. Shift your rear into the lowest (furthest inside) gear, and the front into the lowest (furthest inside, again) gear. Tighten the low limit screw (should be marked with an L. If not, play a bit until you figure out which is which) until the inside part of the derailleur cage is close to the chain, but not rubbing. I'd say 1-2 mm. If it's too close, it may not downshift correctly, but if it's too far away, it may throw the chain inwards.

Now, loosen the anchor bolt that holds the cable, pull it tighter with your hand (or some pliers if you need a better grip) so there's little slack, and retighten the anchor bolt. Make sure the cable isn't super tight, but not really slacky.

Now, shift the bike to the highest (outermost) gears in the front and back. Pull the cable with your hand to see if the derailleur tries to throw the chain all the way off. If so, tighten the high (H) limit screw bit by bit, so that the derailleur doesn't rub, but doesn't throw the chain off.

Try shifting it and see if it shifts properly. From this point on, you should only need to fine tune the cable tension.

I know this is a lot of rambling, but just play with it, and you'll get the hang of it. Hope this all helps.
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Old 07-05-05, 06:44 AM   #3
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Quote:
Originally Posted by Booger
Couple quick questions from a newbie...

1) I noticed that the chain rubs the derailer in gears 1-3, but when I adjust it (using the top screw closest to the frame), the chain starts to rub in the higher gears. Is there a way to alleviate all the friction? It doesn't seem possible the way things are setup now.

2) There are 2 adjustment screws on top of the derailer. The one closest to the frame obviously moves the derailer laterally. What's the 2nd one for?

My bike:
KHS Flite 750
Ultegra Derailers

ETA: I did find this article at Sheldon Brown. Very helpful.
Your shifters have trim. Proper use of that feature takes care of typical rub. If your FD is mal adjusted, check the repair section at www.parktool.com and start the adjustment process at the beginning
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Old 07-05-05, 06:48 AM   #4
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Quote:
Originally Posted by Devious Golden
It's a process to get it right, but it makes it easier to take it step by step.

First, I make sure the cage is aligned parallel to the outside chainwheel. You can do this by physically pulling the cable with your hand, and eyeing the outside edge of the derailleur cage to see if it's reasonably parallel. Make sure it has at least a 1 mm clearance over the outside chainwheel also. You may be able to skip these steps.

Now we'll set the inside limit screw. Shift your rear into the lowest (furthest inside) gear, and the front into the lowest (furthest inside, again) gear. Tighten the low limit screw (should be marked with an L. If not, play a bit until you figure out which is which) until the inside part of the derailleur cage is close to the chain, but not rubbing. I'd say 1-2 mm. If it's too close, it may not downshift correctly, but if it's too far away, it may throw the chain inwards.

Now, loosen the anchor bolt that holds the cable, pull it tighter with your hand (or some pliers if you need a better grip) so there's little slack, and retighten the anchor bolt. Make sure the cable isn't super tight, but not really slacky.

Now, shift the bike to the highest (outermost) gears in the front and back. Pull the cable with your hand to see if the derailleur tries to throw the chain all the way off. If so, tighten the high (H) limit screw bit by bit, so that the derailleur doesn't rub, but doesn't throw the chain off.

Try shifting it and see if it shifts properly. From this point on, you should only need to fine tune the cable tension.

I know this is a lot of rambling, but just play with it, and you'll get the hang of it. Hope this all helps.
Cable should have been looose before diddling with the low limit.And mindlessly playing with it usually doesn't fly.
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Old 07-05-05, 07:34 AM   #5
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Quote:
Originally Posted by sydney
Cable should have been looose before diddling with the low limit.And mindlessly playing with it usually doesn't fly.
I agree with Sydney. Every front derailleur adjustment affects every other adjustment. If you don't get the low limit set right, with no tension on the shift cable, it can cause adjustment issues farther down the line. Lots of guys have lots of problems setting up front derailleurs, expecially when using STI shifters. I think that most of those troubles are caused by not following the correct sequence of adjustments.
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Old 07-05-05, 09:18 AM   #6
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Originally Posted by Retro Grouch
I agree with Sydney. Every front derailleur adjustment affects every other adjustment. If you don't get the low limit set right, with no tension on the shift cable, it can cause adjustment issues farther down the line. Lots of guys have lots of problems setting up front derailleurs, expecially when using STI shifters. I think that most of those troubles are caused by not following the correct sequence of adjustments.
I'll second RG and Sydney. I made the mistake of looking at mine, going "Oh, that's not so tough", and starting the adjustment process someplace in the middle, then randomly turning things until I got it FUBARed. A quick trip to the Park Tools Site, print out the directions, follow them EXACTLY, and in no time I had a beautiful shifting FD. Lesson Learned: RTFM, RTFM, and when that fails, RTFM Again.

Steve W.
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