Aargh, freehub failure- freewheel always engaged

Northwind
Northwind Posts: 14,675
edited October 2008 in MTB workshop & tech
Or, something to that effect- basically the cassette spins freely and isn't providing drive to the rear wheel. It's a wee bit intermittant- it failed on the way home, started working again, failed again... Dumped it in the garage and now it works again.

It's a Carrera Kraken 08, the hub is unbranded or at least not logo'd, cassette is a SRAM X5 if that makes any difference (though I suspect not). I serviced the wheel bearings last week and I did notice that the freehub was a little louder than normal, it sounded a wee bit gritty- but after a short test ride, that went away. It might not be connected, but I thought it worth mentioning.

Any suggestions? I don't mind things that just fail, but things that fail then unfail drive me mad :roll: I don't have the tools to break down the freehub but I can easily get them, just wondering what I'm actually looking at here...
Uncompromising extremist

Comments

  • nicklouse
    nicklouse Posts: 50,675
    you need a new freehub talk to halfords.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Northwind
    Northwind Posts: 14,675
    Gah! I was trying to avoid that since I know more about bikes than they do :wink: No point in stripping and servicing the thing?
    Uncompromising extremist
  • ride_whenever
    ride_whenever Posts: 13,279
    shimano freehubs are basically non-servicable. Basically just buy another hub and replace the freehub
  • Northwind
    Northwind Posts: 14,675
    Is that possible without rebuilding the wheel? IE, can I just replace the freehub but not the main hub? I can't build wheels to save my life :roll:
    Uncompromising extremist
  • irony
    irony Posts: 43
    You don't rebuild the wheel.

    Remove the cassette, remove the axle (catch the bearings as they fall out), then you'll need a 10 mm hex key to remove the freehub.
    2750921120_2950536dcb_s.jpg
  • Northwind
    Northwind Posts: 14,675
    lovely, nice and easy then. Thanks for the help! (I can do anything with spanners as long as I've got a starting point, but I'm still getting to grips with bikes)
    Uncompromising extremist
  • Not sure about easy - those b*ggers are TIGHT.

    You will also need a chain whip, cone spanners and a cassette removal tool if you don't already have them, plus grease if your bearings are not sealed units. A short piece of pipe is also useful to fit over the allen key and get some leverage.

    Alternatively you can get a 10mm long arm allen key, Draper do one for servicing car caliper brakes.

    You may find the freehub hex size is not 10mm (it is 10mm for Shimano but others can vary) so be prepared with 11mm and 12mm just in case. New freehubs sometimes come with a hex wrench adapter to convert to 10mm.

    Marv
    What tree ? ...........

    Trek 8000 ZR XC hardtail.
  • Northwind
    Northwind Posts: 14,675
    No worries, I've got long allen sockets and a 3 foot breaker bar in the garage 8)
    Uncompromising extremist
  • AndyBike
    AndyBike Posts: 126
    Swopped my freehub recently, Shimano too, it drags slightly locknut probably a little to tight. Hardest part was setting the play in the cone and cone locknut to very slight play, which is pulled in when the skewers are tigtened - took hours, and managed to strip the spindle overtightening the lock nut first time. The lock nut and cone had come loose from shop/factory fit hence my enthusiasm tightening nuts! Wheels ran great greased and newly fitted.

    Andy
  • Northwind
    Northwind Posts: 14,675
    Yeah, that's a fiddle the first couple of times you do it...

    Well, the nice part is, I took the wheel into Halfords and the nice man behind the counter took one look, said "Freehub broken?", I said "Yup", he said "Yeah, happens a lot with these, we'll fit a better one when we replace it... (taps computer) That's it ordered, it'll be here by wednesday." So I prepared myself to lie about the warranty (I got the bike used) and just as I opened my mouth he says "Don't worry about the warranty paperwork, it's an 08 bike so it'll be covered"

    Some bikehut people are alright, you know 8) I'd write to his boss and say thanks but he'd probably get fired for not trying to rip me off.
    Uncompromising extremist