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Old 07-09-12, 08:44 AM   #1
yannisg
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RD running roughly on lowest gear

I have front chain rings 22/32/42 and installed a rear cassette 11/32 using Deore LX RD. I can shift into 42/32, but chain is tight so chain tension is ok. When using smallest gear 22/32 RD does not run smoothly even though RD is adjusted correctly. When using next to lowest gear 22/28 RD runs smoothly. RD runs smoothly in all others gears.
Any recommendations how to solve this will be appreciated.
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Old 07-09-12, 08:54 AM   #2
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how close is the derailleur cog to the cassette cog? b-tension is most important in the lowest gear - if the two are touching when they run it will make ugly grinding noises and feel rough when you ride. try screwing in the b-tension screw... or post a picture of the derailleur while its in the lowest gear in the rear.
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Old 07-09-12, 10:02 AM   #3
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Djembefora, thanks for the response.
The upper RD pulley is rubbing slightly on the 32 sprocket even though b tension screw is all the way in. Maybe with a longer b tension screw I could get them separated.

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Old 07-09-12, 10:17 AM   #4
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Sounds like you've exceeded your rear derailleur's capacity -- have you switched from a double to that triple, or installed a cassette with a much larger cog than stock? You may need to install an RD with a longer cage.
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Old 07-09-12, 11:33 AM   #5
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[QUOTE=yannisg;14457141]..... I can shift into 42/32, but chain is tight so chain tension is ok. When using smallest gear 22/32 RD does not run smoothly even though RD is adjusted correctly.........

Hardly a definitive test for proper chain length!
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Old 07-09-12, 11:37 AM   #6
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Cage length will not solve the problem. Long cages are for wrapping up chain slack. If you can't get the clearance you need with a longer B screw then you'll need a mountain type RD.
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Old 07-10-12, 04:01 AM   #7
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Bill,
Thanks for yr response. I just mentioned the 42/32 combination to show that the problem was not caused by the length of the chain being too long.
Thanks,
YannisG
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Old 07-10-12, 04:08 AM   #8
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Al1943,
Thanks for responding.
The RD I am using is Deore LX which is a mtn type RD.
Thanks,
YannisG
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Old 07-10-12, 05:39 AM   #9
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Bill,
Thanks for yr response. I just mentioned the 42/32 combination to show that the problem was not caused by the length of the chain being too long.
Thanks,
YannisG
Uh, that leaves too short. You need to check chain length, as too short can definitely cause noise. Poor derailleur hanger alignment is also a possible cause.

Last edited by cny-bikeman; 07-10-12 at 05:25 PM.
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Old 07-10-12, 06:02 AM   #10
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If the B screw length is the problem, then perhaps you can reverse the B screw as noted in the following link?

http://sheldonbrown.com/deakins/lowgears.html
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Old 07-10-12, 07:59 AM   #11
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Hi lvolpe,
Thanks for the link; very informative and relative to my problem. Looks like I can reverse the screw temporarily until I get a longer one.
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Old 07-10-12, 04:42 PM   #12
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Hi lvolpe,
Thanks for the link; very informative and relative to my problem. Looks like I can reverse the screw temporarily until I get a longer one.
YannisG
If the backwards screw works, I suggest keeping this as the permanent solution.

A longer screw may NOT actually work as the angle of the longer screw may cause the screw to miss the little tab on the hanger, effectively making the screw shorter. The head of the original screw will likely sit on the tab better.
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Old 07-10-12, 05:21 PM   #13
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Quote:
Originally Posted by yannisg View Post
Djembefora, thanks for the response.
The upper RD pulley is rubbing slightly on the 32 sprocket even though b tension screw is all the way in. Maybe with a longer b tension screw I could get them separated.

YannisG
Some rear derailleurs have multiple possible positions for the end of the B-tension spring opposite of the body. You might be able to make that adjustment, taking the opportunity to clean and lubricate your derailleur upper pivot whilst it's apart.
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