Forum home Mountain biking forum MTB workshop & tech

New freehub needed , which one ?

bing gordonbing gordon Posts: 662
edited October 2016 in MTB workshop & tech
I have just bought a 2nd hand Specialized 8 speed Rockhopper but the freehub paws are knackered as it slips alot. The freehub is a sealed freehub with the teeth / cog at the bottom to interlock with the bike so I can't get the paws.

I've had a quick look but there seems to be a few different models made by Shimano ones but I'm not sure which I need.
Any idea's ?
Alexrims Specialized

Posts

  • cooldadcooldad Posts: 32,904
    Depends on the hub.

    Doesn't sound like a Shimano hub from your description?
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • It looks like this from the bottom side:-
    http://www.chainreactioncycles.com/shim ... lsrc=aw.ds
    With the teeth that drop onto teeth on the bike itself but there's quite a few different model numbers
  • The RookieThe Rookie Posts: 27,747
    So you need to find out what exactly the hub you have is, a Spesh dealer is probably the best bet.

    A decent used wheel may be a better bet.
  • The Rookie wrote:
    A decent used wheel may be a better bet.

    ummm , that' sounds abit extreme, a new wheel for a knackered freehub ?. The bikes only about 7-8 years old so I would imagine someone will still be making a compat, freehub the problem is, I just don't know which to buy, I will email specialized and see what they say.
  • cooldadcooldad Posts: 32,904
    So sorted.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • cooldad wrote:
    So sorted.
    Er not so quick Batman :)

    while hunting around for the best price I dropped on this video;-

    https://www.youtube.com/watch?v=O_tEbQpjYiU

    After I removed the Freehub Body from my bike which I now know is a FH-RM30-8speed via Specialized I thought the unit was totally sealed unlike my road bike were I can service the bearing and paws but the video seems to confirm you can actually open the freehub and get at the internals to clean and repair which I do every so often with my road bike.

    I've a feeling it's the exact same problem in the video as mine , just muck holding back the paws from releasing quickly enough to engage hence the slipping and freewheel/coasting I get which gave me one hell of a bruise via the peddle winging it's way onto the back of my calf when setting off.

    Can anyone confirm this and the method on how to open it ?. I don't see the point buying a new one for £20 when I can simply service this one especially when I have all the gear to do it.
  • cooldadcooldad Posts: 32,904
    So take it off and look.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • keef66keef66 Posts: 13,286
    It's pawls. Paws are what a bear walks on.

    On Youtube somewhere there's a video of somebody making a tool by grinding down an old socket and using it to dismantle a Shimano freehub, maybe yours is the same?

    But for £15 I'd just buy a new one.

    Maybe when I'm retired and scraping by on a pension i'll have enough free time and motivation to open up a freehub. For now I just take them off once a year, pick out the rubber seal, and drizzle a load of motor oil in there. Give it a few spins then drain it out with a load of dirt. Repeat if required, replace the seal and reinstall the freehub. This is on 2 road bikes, one of which is ridden through the winter, and I haven't had a freehub fail on me in nearly 10 years.
  • I took a couple of pictures, I made one of those tools awhile back and it worked fine but there's no slots on this. There's a thread on the inside as though the center screws out but I can't see how you unscrew it without putting force on it and knocking it out of shapeifn23t.jpg
  • keef66keef66 Posts: 13,286
    Isn't that internal thread the one for the lockring?

    Maybe they've made the cheaper ones completely non serviceable...
  • A friend I asked earlier online has just this minute sent me this link (50 seconds in)
    https://www.youtube.com/watch?v=X9gIEG1db0s
    I don't have one but I have a large blot and washers I used in the past for a bearing press, I'm wonderimng it that would work ?
  • I finally sussed it, I removed the dust cover which was a pain then using the socket I made got to the insides only to discover the reason for it skipping a beat, the teeth on the inside of the freehub were badly worn and a few bearings were missing plus the bearing track badly scratched up.

    I have just ordered a new one but it was worth a go, nothing lost bar a few hours sussing out. Thanks for any help given.


    @keefe , I did try cleaning first before having a go at taking it apart, and, these bears ? do they have caws growing out their pawls ? thanks for the grammar lesson , much appreciated eye hoe ewe Juan :) .
  • keef66keef66 Posts: 13,286
    Cheers for the update! As I say I may end up needing to do this one day when I'm old (er) and penniless.
  • keef66 wrote:
    Cheers for the update! As I say I may end up needing to do this one day when I'm old (er) and penniless.
    Some people just don't have it when it comes to fixing stuff but good luck when father time catches you up and save all your old thrown out parts, you should have a skip full by the time your bus pass arrives.

    As a follow up,
    I tried to locate a F-RM33 8 speed but was having truoble locating one till Wollyhatshop confirmed that a FH-RM33 next model up
    like this https://www.sjscycles.co.uk/hub-spares/ ... y30v98040/

    is compatible with any bike fitted with a FH-RM30, the 33 is just a vamped up model.
  • Just to confirm the FH-RM33 is the alternative replacement for the RM30 , I ordered one and fitted it yesterday
Sign In or Register to comment.