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Rubbing of largest sprocket and upper pulley

dizzyblonde82dizzyblonde82 Posts: 100
edited July 2011 in MTB workshop & tech

I am having a difficult time getting my rear shimano derailleur to work correctly, I have got it shifting up and down the gears fine but the upper pulley seems to be rubbing on the largest sprocket, the 'b' screw on it is screwed in as far as it can go but it doesn't seem to increase the distance between the sprocket and upper pulley.

Any suggestions on how to fix this and could this be down to a bent hanger? I did have a fall of my bike and the rear derailleur did take a knock.



  • nicklousenicklouse Posts: 81,520 Lives Here
    most likely if as I presume it all worked fine before?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • It did work before the fall and have been having problems with the gears since, would it be the hanger or should I be looking to replace the derailleur as it is only a very basic shimano one.
  • nicklousenicklouse Posts: 81,520 Lives Here
    the replaceable hanger has a job to do and that is bend.

    look at that first. it is possible that the mech is damaged but if it is the hanger will also be.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Have taken the hanger off and it looks fine, the derailleur doesn't look too good.

    Trying to find some pictures online of the model SHIMANO, RD-M410 and mine looks like it is bent.
  • supersonicsupersonic Posts: 82,708 Lives Here
    We need a pic of the derailer attached, looking forward from directly behind.
  • P1000596.jpg


    Looking at these pictures the hanger does look bent.
  • johnsavjohnsav Posts: 775
    looks slightly bend inwards to me
  • mattvmattv Posts: 992
    Wind the b tension screw right out, then back in again. Sometimes I have seen the springs or the screw hop in a crash. Otherwise, try gently bending the hanger straight by hand. Cant break it more than it is now, watch for cracks when you do it.
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