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[Closed] Lose cassette, knocking rear hub

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Hi all,

I have 2 1/2 year old XT hubs (QR). They both spin pretty freely, however the rear is starting to knock, so I'm guessing they'll need serviced. I'll be doing it myself. First stupid question of the day, any particular grease for these lose ball bearings?

Secondly, my cassette has come lose for the 2nd time in about 6 months. First time I got my LBS to tighten it for me, because no matter how correct I seemed to have installed it, it just kept being lose. Is this something to do with the hub axle assembly rather than the cassette itself? I want to sort this ASAP as I'm commuting 50-70 miles per week on the bike.

Cheers

Colin


 
Posted : 30/11/2011 5:41 pm
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Hi Colin, the purpose of the grease is to keep water out of your nice hubs so look for a good water resistant grease. I like Park's Polylube 1000 or Weldtite 2f2 with Teflon.
Not sure why your cassette is working loose. It won't be to do with the axle because it fits direct to the freehub body which is separate from the axle. I suppose you could try some loctite on the cassette lock ring threads?


 
Posted : 30/11/2011 5:53 pm
 Sam
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Is it the cassette coming loose or the freehub body?


 
Posted : 30/11/2011 6:03 pm
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Firstly, good luck with your attempts to solve the issue that you describe, as I appreciate how much faith you have to have in your commuter bike.

Secondly - and only slightly tongue in cheek - I hope you're freehub doesn't come lose, or your likely to loose the back wheel.
And, if you suffer a break failure on a descent sized decent, you may brake a leg.
😉


 
Posted : 30/11/2011 7:04 pm
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Have you torqued the cassette up correctly? Shimano cassettes require 40Nm, which I read as tight as you possibly can. First time I put on a cassette I thought it was on tight, but in a month it had worked itself loose.

As above make sure it's not the freehub which is loose, if the knocking is coming from the freehub it could mean you need a replacement.


 
Posted : 30/11/2011 7:29 pm
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Is it a SRAM cassette?Mine was doing that and it was actually play between the sprockets an the alloy carrier


 
Posted : 30/11/2011 7:55 pm
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Thanks for the replies. Yes, it's a SRAM cassette, PG970. On further inspection this morning the wheel seems to be slightly lose itself too, as in holding the bike up and wiggling the rear wheel at the top shows some play, but not as much as the cassette.

Maybe I should just get the bus?


 
Posted : 01/12/2011 10:53 am
 Sam
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Thanks for the replies. Yes, it's a SRAM cassette, PG970. On further inspection this morning the wheel seems to be slightly lose itself too, as in holding the bike up and wiggling the rear wheel at the top shows some play, but not as much as the cassette.

Maybe I should just get the bus?

Sounds suspiciously like the hub bearings and the freehub are done for. Replacing the freehub body is fairly straightforward, so long as you can find a replacement. Once you have the axle out, then it's a 10mm allen key inside the freehub body. Your LBS should be able to order a replacement freehub body given the model number of your hub.


 
Posted : 02/12/2011 12:56 pm
 Tim
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Wheels need a service - pretty easy but need some skinny spanners.

I've had the cassette thing - first time the freehub had worked loose from the body of the hub (its a big 10mm allen key behind the axle bearing assembly, well it was anyway).

2nd time i managed to crack the freehub in half and rip the spline off the hub. That time the freehub spun on the hub, and the cassette fell off as there was no tension the threads 🙂

I'd strip the hub, take the freehib off, check the threads and palws on both hib body and freehub, clean, slither of grease and reinstall if all ok.

clean an check threads on cassette locking and freehub, and check the cassette is seating down properly so the lockring is threading down enough to hold it. You shouldnt need locktite.


 
Posted : 02/12/2011 1:20 pm
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Thanks Sam.

How can I tell if it is the freehub body for sure?

I don't want to waste £30 on a replacement one for the problem to come back after half a dozen rides.

And and cheers Tim. I'm hoping to strip the hubs this weekend, I bought some new cone spanners.

Thanks

Col


 
Posted : 02/12/2011 1:25 pm
 Tim
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The freehub may have some play - make sure its peoperly tightened down and see if it has some 'wobble' - easier with the cassette on there and correctly tightened. Some always seem to have a little bit of play though.

Either way, as long as the thing isnt falling apart and the threads and pawls are ok, it shoudn't come loose.

I may have a spare shimano rear hub kicking around that can be scavenged for parts. Cant remember if i gave the wheel away though...


 
Posted : 02/12/2011 1:41 pm
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Well, this weekend I stripped the rear hub. Bearings on one side completely gone, pretty much no grease, badly pitted race, cone and bearings. Freehub lose. New hub and wheel rebuild time!


 
Posted : 13/12/2011 12:23 pm
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st colin - Member

Well, this weekend I stripped the rear hub. Bearings on one side completely gone, pretty much no grease, badly pitted race, cone and bearings. Freehub lose. New hub and wheel rebuild time!

2 1/2 years of riding without bothering your arse to service them... you deserve it!

Who's rebuilding it? Do it yourself!


 
Posted : 13/12/2011 12:43 pm
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Chuck Norris.


 
Posted : 13/12/2011 4:38 pm
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Doubt you'll be needing this then! - Sound like a right off !

http://www.cyclistno1.co.uk/features/maintenance/xt-hub-service.htm


 
Posted : 13/12/2011 4:54 pm