Rear mech becomes misaligned when tighten quick-release skew

willfurnass
willfurnass Posts: 3
edited April 2011 in MTB workshop & tech
Hi,

I have a On-One Scandal frame (26"; vertical drop-outs), a Shimano FH M475 rear hub and a Shimano XT rear mech. Before I tighten my quick-release skewers the jockey wheels and cassette sprockets all appear to be vertically aligned. However after tightening the rear skewer the mech tilts in towards the spokes, which seems make changing gear rather clunky.

I've laid the two long plates of my rear mech and my detachable mech hanger on a flat surface and none appear to be bent.

Has anyone else encountered this problem before?

Cheers,

Will

Comments

  • ricardo_smooth
    ricardo_smooth Posts: 1,281
    index the mech up with the wheel in place.....Simples :)
  • redvee
    redvee Posts: 11,922
    What side is the qr on? Try it on the non-drive side.
    I've added a signature to prove it is still possible.
  • willfurnass
    willfurnass Posts: 3
    Thanks for the suggestion redvee; unfortunately flipping the QR skewer didn't make any difference.

    I've checked that I've got the correct axle spacers as per Shimano's exploded diagram of the FH-M475 hub but am going to try adding an extra spacer on the cassette side, which should hopefully prevent the seat-stays from being pulled towards each other when the QR is tightened.

    Any other suggestions greatly appreciated.
  • Northwind
    Northwind Posts: 14,675
    Remove the mech hanger, clean and check fit, refit, see if that helps. If not, unbolt mech hanger, bolt wheel in, then rebolt mech hanger, that might work.
    Uncompromising extremist
  • nicklouse
    nicklouse Posts: 50,675
    why would you be setting up a mech without the Qr being correctly tightened?


    yes some times a frame can be sprung a little wider than the hub width.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • ricardo_smooth
    ricardo_smooth Posts: 1,281
    nicklouse wrote:
    why would you be setting up a mech without the Qr being correctly tightened?
    My point exactly
  • Northwind
    Northwind Posts: 14,675
    Not sure that's exactly what's being asked here- if I read the first post right, the hanger's pulling out of alignment when the QR's tightened.
    Uncompromising extremist
  • twonks
    twonks Posts: 352
    To me, if it being pulled over when tightened-something is bent !

    Looking down the line from the rear of the bike, you should be able to see what is moving when you tighten the QR. Work from there to determine what is.

    I've had it before and the mech hanger was bent, even though it appeared not.

    As it is the cheapest part of the potential problem it is worth replacing to eliminate it from the problem.

    If all looks well and it still pulls over, maybe check frame welds in the area to make sure one of them isn't split. (although I'd think this would be more evident when riding)

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