Advertise on Bikeforums.net



User Tag List

Results 1 to 8 of 8
  1. #1
    Senior Member TNDave's Avatar
    Join Date
    Nov 2009
    Location
    Knoxville, TN
    My Bikes
    2008 Gary Fisher Monona, 1997 Univega Alpina 550, 1980 Nishiki International, 1993 Specialized Epic
    Posts
    160
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Jockey Wheel Cage Rubbing against chain making the chain pop

    I picked up a bike at a garage sale a couple of weeks ago and have had so much fun riding it I just now today made time to clean and inspect it thoroughly. In one gear combination, I don't remember which, the cage on the upper jockey wheel of the rear derailler rubs the chain and causes the chain to "pop" and click when it goes past the cage. I can try to get a picture of it if it helps, but I have never seen this before and have no clue what to look for or how to fix it. Any ideas would be greatly appreciated!
    "The problem with Internet Quotes is that they are impossible to verify" - Abraham Lincoln

  2. #2
    Licensed Bike Geek Davet's Avatar
    Join Date
    Oct 2002
    Location
    Spokane, Washington. Bicyclist's heaven!
    My Bikes
    Kirk Terraplane, Serotta Ottrott, Spectrum Super Custom, Hampsten Carbon Leger Tournesol
    Posts
    938
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Does it happen when the chain is on the small ring and big cog? If so, then you'll need to adjust the B-screw by turning it in until there isn't any "chain rumble" when the crank is turned backwards, in that gear combo. Easiest to do in the stand.

  3. #3
    Senior Member IthaDan's Avatar
    Join Date
    Jan 2012
    Location
    Ithaca, NY
    My Bikes
    Click on the #YOLO
    Posts
    4,620
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    B-bolt.

    Shimano : Click :: Campy :: Snap :: SRAM : Bang

  4. #4
    Mechanic/Tourist
    Join Date
    Apr 2007
    Location
    Syracuse, NY
    My Bikes
    2008 Novara Randonee - love it. Would have more bikes if I had time to ride them all. Previous bikes: 1968 Motobecane Mirage, 1972 Moto Grand Jubilee (my fav), Jackson Rake 16, 1983 C'dale ST500.
    Posts
    4,677
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    I don't see how the B tension screw would have any effect on the idler pulley cage rubbing the chain. The cage should always be in a plane parallel to the vertical front to back plane of the bike frame (or freewheel). In that position, with the chain coming directly off the freewheel, there is no gear combination where the the cage would rub anything except the freewheel cogs, in which case b-tension adjustment would be in order.

    The only way for the cage to rub on the chain, other than just plain bad tension adjustment, is if the assembly is badly misaligned. That calls for a trip to the shop to check hanger alignment and any possible damage to the derailleur cage.

  5. #5
    Senior Member IthaDan's Avatar
    Join Date
    Jan 2012
    Location
    Ithaca, NY
    My Bikes
    Click on the #YOLO
    Posts
    4,620
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    Sounded to me like either the chain was too long and the gear that gave the trouble was small-small (perhaps on a triple with a large tooth spread and a underequipped RD cage). Or an issue with inconsistent cog spacing. Both of these can be remedied in a pinch with a b-bolt.

    Agreed on the alignment, sometimes, a bent cage or hanger only acts up in one gear. Especially if we are to take this noise as the chain hunting for the next larger cog.

    Either way, I'd start with the b-bolt.

    Shimano : Click :: Campy :: Snap :: SRAM : Bang

  6. #6
    Licensed Bike Geek Davet's Avatar
    Join Date
    Oct 2002
    Location
    Spokane, Washington. Bicyclist's heaven!
    My Bikes
    Kirk Terraplane, Serotta Ottrott, Spectrum Super Custom, Hampsten Carbon Leger Tournesol
    Posts
    938
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Another and likely possibility is that the upper jockey pulley bearings/bushing may be worn enough to give the pulley too much sideways (lateral) movement, which would allow the chain to move the pulley far enough to the side and allow the derailleur cage to interfere with the chain. That pulley has a small amount of sideplay built in, about 1mm in either direction. If that's the case, it's time for a new pulley.

  7. #7
    Senior Member TNDave's Avatar
    Join Date
    Nov 2009
    Location
    Knoxville, TN
    My Bikes
    2008 Gary Fisher Monona, 1997 Univega Alpina 550, 1980 Nishiki International, 1993 Specialized Epic
    Posts
    160
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Think I found it, the derailler shifter tension is allowing it to "half-shift" and get kinda stuck and hunting between shifts and that is when it would rub. It seems to be worse in the small-small combination, so maybe the B tension bolt would help also? I definitely need to adjust the tension so that it can't half shift. The pulley teeth look OK to me, but I am going to get my shop to take a look also.
    "The problem with Internet Quotes is that they are impossible to verify" - Abraham Lincoln

  8. #8
    Senior Member
    Join Date
    Sep 2010
    Posts
    2,578
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    "the derailler shifter tension is allowing it to "half-shift". Follow this procedure from the beginning without skipping any steps, to correctly adjust your derailleur: http://www.parktool.com/blog/repair-...nts-derailleur

    "It seems to be worse in the small-small combination" Do not cross-chain; you have similar, more efficient gear combinations available which will be quieter and not wear the drivetrain as much.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •