# Strange sound from Mavic Cosmic Carbone SL rear wheel



## ashpelham (Jan 19, 2006)

I'm observing a rather loud noise coming from my rear wheel when descending down hills, while not pedaling. In fact, the sound goes away when I do start pedaling. The sound is very similar to what one would hear if a brake pad was rubbing heavily against the rim, but I've checking into that. There is nothing else rubbing the rim, and, again, the sound stops when I start pedaling again. I notice no difference in the wheels actual performance, but the sound is very loud. Sounds like something is up. I'm suspecting it's the freewheel, since I only hear when not pedaling.

Common issue? These are 2009 Carbone SL rims. Tires are old, old old. And the skewer I'm using is from my bike trainer.

Thanks for the help in advance.


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## coachboyd (Jan 13, 2008)

Check to see if the adjusment on the hub has tighened. This can keep the freewheel moving and can cause a loud almost squealling sound. You may just have to undo the hub tightness a slight bit. You'lll need a special tool to do this, but it should have come with the wheels.


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## ashpelham (Jan 19, 2006)

Thanks coachboyd, I'll check that. I know the tool you are talking about and I've got several. By the way, I totally dig you guys' wheels and they are next on my list. Looking for something with less depth than the 50mm Cosmic Carbone's. Something like the Vitesse.


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## coachboyd (Jan 13, 2008)

Very cool! Just let me know if you have any questions. Email usually works best.


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## Kerry Irons (Feb 25, 2002)

*Plastic bushing*



ashpelham said:


> I'm observing a rather loud noise coming from my rear wheel when descending down hills, while not pedaling. In fact, the sound goes away when I do start pedaling. The sound is very similar to what one would hear if a brake pad was rubbing heavily against the rim, but I've checking into that. There is nothing else rubbing the rim, and, again, the sound stops when I start pedaling again. I notice no difference in the wheels actual performance, but the sound is very loud. Sounds like something is up. I'm suspecting it's the freewheel, since I only hear when not pedaling.
> 
> Common issue? These are 2009 Carbone SL rims. Tires are old, old old. And the skewer I'm using is from my bike trainer.
> 
> Thanks for the help in advance.


MAVIC uses a plastic bushing between the hub body and the freehub. That needs to be lubed. The noise is common, and apparently is considered a "feature" that tells you when to lube the part.


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## jlharden (Sep 23, 2007)

Had the same issue on a Crossmax SLR wheel not long ago. A complete cleaning of the freehub and proper lubrication with a light machine oil(Mavic sells a freehub specific lube, but Singer sewing machine oil seems to do the job!) has had it back as good as new. Definitely, a known issue with the Mavic freehubs. Good luck!


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## ashpelham (Jan 19, 2006)

Any specific tools to take that freehub off the wheel so as to service it? I'm guessing yes, and in my neck of the woods, it's absolutely cheaper to buy the tool and do yourself. Not that experienced in wheel works myself.


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## cxwrench (Nov 9, 2004)

i just posted this in another thread...1 5mm allen wrench, 1 10mm allen wrench and the mavic bearing adjustment tool 
Excel Sports: How to service a Mavic Freehub - YouTube


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## 2Slo4U (Feb 12, 2005)

jlharden said:


> Had the same issue on a Crossmax SLR wheel not long ago. A complete cleaning of the freehub and proper lubrication with a light machine oil(Mavic sells a freehub specific lube, but Singer sewing machine oil seems to do the job!) has had it back as good as new. Definitely, a known issue with the Mavic freehubs. Good luck!


had this happen to both my mtn set and road set. clean the hub and re-lube. If problem comes back, then you need a new bushing and potentially a new hub. First time it happened to me was on my mtn bike, it sounded like the tire was rubbing on the chainstay. Scared the crap out of me because I thought i had broken my frame (not a good feeling!)


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## cmg (Oct 27, 2004)

anyone replace the plastic bushing with a real bearing? what size bearing?


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## gibson00 (Aug 7, 2006)

cmg said:


> anyone replace the plastic bushing with a real bearing? what size bearing?


I do not believe it is meant to be replaced.
Like the others said, remove the freehub (carefull not to lose the two springs underneath!!), wipe it clean inside and out, add some light lube inside and over that yellowish bushing, reinstall. You'll be good to go.

Edit - OK, I guess you can replace them. But unless it is really old, I'd just try the cleaning first.


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## TimInSeattle (Jan 2, 2012)

Oh yes, the Mavic death squeal! If this goes on very long you will damage the main wheel hub. Frequent lubing is required to avoid this. I use Road Rage by Pedro since it is a mineral oil very similar to the Mavic oil. See the Rogue Bike Mechanic for his video on the subj. 

Have never seen a ball bearing for replacing that freehub bushing. There are many Ebay sellers with oversized bushings in cases where the main hub has been damaged and the diameter reduced. Thereby requiring a freehub bushing with a smaller inner diameter.


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