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Trouble Re-fitting Fox Rear Shock

steelosteelo Posts: 541
edited September 2010 in MTB workshop & tech
Can anyone help?

I'm trying to re-fit my rear shock after a service and I can't get the bottom end into the frame, its seems to be a very tight fit and i'm wondering what the best thing to do is to get the damn thing in!

I can't get onto the park tool website at the moment - think they are having a technical problem otherwise i'd check there first.

Fox Float RP2 XV
Trek Fuel EX8 2009

Any help is appreciated - but not "hit it with a hammer" please. :lol:

Thanks
Specialized Rockhopper '07
Trek Fuel EX8 '09

Posts

  • nicklousenicklouse Posts: 50,675 Lives Here
    sounds like you need to press the reducers in a bit more.

    they can be tight fitting.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • steelosteelo Posts: 541
    Can you be a bit more specific about what you mean by "press the reducers in a bit more"?

    Thanks
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
  • steelosteelo Posts: 541
    I've tried to insert the mounting bushes further into the lower part of the shock body by using a bench vice but they are driven in as far as they will go. The only solution I can think of is either to try and prise the frame apart more or to file down the shock mounting bushes. How about submerging the lower part of the shock in ice-cold water to try and reduce the size of the bushes if they are supposed to be an interference fit?!?

    Any more suggestion?
    Do you think it's possible that Mojo refitted the wrong mounting bushes into the lower shock body?
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
  • nicklousenicklouse Posts: 50,675 Lives Here
    edited August 2010
    maybe what is the difference between the opening and the width of the reducers?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • konadawgkonadawg Posts: 447
    Don't misunderstand this, but you could possibly take off the sharp edges off the reducers and also the frame tabs so as to get everything "started". Judiciously, with a block of wood as an intermediary and not applied to any working / sealing part of the shock, you could then tap the lower in. With a hammer...

    If you have the space / design allows and especially but not only if you have two positions for the lower -

    Consider feeding a longish bolt through the tab holes first, with a couple of nuts on the inside of the tabs, then unscrew the nuts so that they open out the tabs just sufficiently to get the reducers started in the tabs. Then remove the bolt out of the way and push/tap the shock as previous to fully install.
    Giant Reign X1
  • steelosteelo Posts: 541
    Just measured the components, shock reducers measure ~39.5mm and the space between the lower swingarm tabs is ~39.0mm so only a difference of about 0.5mm from what I can measure using a retractable tape measure.

    I really don't want to file, cut, or modify anything but surely there should be technical specifications detailing what the fit/tolerance of the parts should be?!?

    I've just had a closer look at the rear shock and noticed that the stickers now say RP23 and not RP2 as the shock originally was when it was sent to Mojo - is this something that Mojo typically do? Rebrand their serviced shocks as more expensive models???
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
  • konadawgkonadawg Posts: 447
    Sorry just saw the "trek ex8" bit.

    Not very familiar but could you loosen the pivot bolts for the chainstay bearings, would this potentially allow the chainstay ends to open up a bit allowing the reducers/shock to fit?

    Also was the lower shock DU bearing replaced by Mojo at the service, could it be poorly centred in the eyelet not allowing one reducer to seat sufficiently? Or possibly slightly oversize (width)?
    Giant Reign X1
  • steelosteelo Posts: 541
    Can anyone tell me what the overall widths of the mounting hardware should be for a Trek Fuel EX8 with a Fox Float RP2 fitted?
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
  • edjoedjo Posts: 50
    they are a really tight fit so it isn't wrong. the tips tend to close up when the shock is removed so, lightly grease the shock mount, and draw the shock in from behind the tips where the mount is welded to the frame as it tends to be wider there. this should allow you to do it with no file or hammer. the little bit of grease will allow you to line the shock up once it's in the tips.
  • cavegiantcavegiant Posts: 1,546
    Some frames are designed like this, is this a niner frame?

    Just use extreme force, it will fit, it is designed to be tight.

    If you can't do it, get a big friend.
    Why would I care about 150g of bike weight, I just ate 400g of cookies while reading this?
  • The mounting kit for my RockShox was really tight. I bought it from TF Tuned so phoned them to make sure it was okay. They said a tight fit was good so I went at it with a rubber mallet. Real censored to get in but I think my problem was the powder coating that had made the gap between the mounts a rizla width thinner! In hindsight I should have used a tiny file to take some of the paint off like I did with my seat tube.
  • steelosteelo Posts: 541
    After talking to Mojo and Trek and with some help from the LBS we fitted the shock. It was actually quite straightforward, released the swingarm mouting bolt and the shock slipped straight in, only because I didn't do this to remove the shock I didn't consider it should be needed to be done to refit it.

    Cheers for the help anyway guys, much appreciated.
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
  • steelo wrote:
    released the swingarm mouting bolt and the shock slipped straight in.
    Probably should have done this myself! :?
  • Don't forget to torque the swingarm bolt back upto the recommended setting
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