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Old 07-19-11, 04:15 PM   #1
SuperGregNo1
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Help with front derailleur adjustment

OK first off I am pretty new to working on derailleurs, and bikes in general. I am trying to adjust the front derailleur on my GF's bike. It is a Shimano Deore LX.

I have:

- Released tension on the cable
- Adjusted the LOW screw
- Reconnected the cable
- Shifted to gear 3 and adjusted HIGH screw

Now, I have trouble with gear 2. It doesn't want to shift from 1 -> 2. I adjusted cable tension a bit at the adjusting barrel at the grip shifter, but then it won't shift from 3->2. If I adjust it back enough for it to shift down to 2, it won't shift from 1 -> 2. If I get it in just the right spot it actually seems to work most of the time but not always. I'm hoping to get it more reliable.

Should I expect it to always shift reliably no matter what rear sprocket is selected? Or should I expect trouble when the chain is on opposite ends of both cassettes?

Any tips would be greatly appreciated!
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Old 07-19-11, 06:23 PM   #2
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go to the Park Tool website and look up "Installing a front derailleur." Pay particular attention to the position of the derailleur on the seat tube. In my experience, that's most often the problem with front derailleur adjustments. The Park Tool site has a good set of step-by-step instructions. Be sure to follow them in order and don't be tempted to skip any steps.
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Old 07-19-11, 08:19 PM   #3
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It may be that there is too much friction along the cable. Excess friction could account for why it hesitates going from 3 to 2. If possible try lubricating the cable inside the housing and at any contact points along its route. You could also try shooting WD40 into the shifter mechanism and lubricating the derailleur's pivot points.
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Old 07-19-11, 09:17 PM   #4
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...and pay attention to the cable's routing at the pinch bolt.
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Old 07-20-11, 12:55 AM   #5
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Quote:
Originally Posted by SuperGregNo1 View Post
Should I expect it to always shift reliably no matter what rear sprocket is selected? Or should I expect trouble when the chain is on opposite ends of both cassettes?

Any tips would be greatly appreciated!
this sounds like cross chaining if im understanding you correctly (ie. smallest on the back and smallest on the front or vice versa) thats bad and you'll have some issues shifting, try to think of your cassettes in groups... last 3 or so on the rear only use when in the biggest in the front, use the middle for the middle and the biggest in the back for the smallest in the front, you'll shift a lot better, and your cassettes will last longer
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Old 07-20-11, 10:35 AM   #6
SuperGregNo1
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Thanks for the info guys, I'll take another crack at it tonight.
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Old 07-20-11, 10:54 AM   #7
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If this is a grip shift, you might also check the cable routing and cable housing leading under the rubber covers on the grip shifter and lube that area too. Slide the cable back out a little if you can and check the condition where it wraps around the shifter body for any corrosion, fraying, etc.
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