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Shimano Bottom Bracket

chillibeerchillibeer Posts: 13
edited October 2010 in MTB workshop & tech
Dear internet,

I have a 2009 Spesh Stumpjumper Elite FSR and have enjoyed a full year of carefree riding. However, I took part in the Chain Reaction Cycle's Marathon two weeks ago in a mud bath. I went through my usual cleaning routine afterwards but when I went to take my bike out this weekend the bottom bracket had seized. I rode it round the block a few times but this hasn't free'd it up.

The bottom bracket is a Shimano FC-M542. Can these be stripped down and cleaned or will I have to buy a new one? Any help or advice would be appreicated.



  • ma9mwahma9mwah Posts: 53
    Seems to be a standard hollowtech2 external bottom bracket. Shimano do have a 'do not disasemble' warning but a few people say they've been successful in removing the seal and regreasing. But even if it's gone to far for that then a new one is only ~£17 from CRC
  • I strip down my FSA external BB to clean & de-grease, take your time - you don't want to damage the seals, I used wooden tooth pick the fist time but now I know how it comes apart I use a very small srewdriver and my finger nails.
  • diydiy Posts: 6,473
    Or warm up the grease insert in a syringe and inject it in leaving the seals in place..

    but since its likely to have gone rusty I would replace it.
  • nicklousenicklouse Posts: 50,675 Lives Here
    mm grease that get thin when warm..

    no thanks a constant viscosity is best as it will not thicken when cold.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • edjoedjo Posts: 50
    "no thanks a constant viscosity is best as it will not thicken when cold"

    all greases thicken / thin depending upon temperature; the oil within the grease changes viscocity as it is cooled or warmed.
    HOWEVER, warming a grease to inject it as mentioned above is unlikely to be effective as it won't thin that much.
    pop the seals, scrub with some solvent / brake cleaner and regrease...if this doesnt work, CRC !
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