Even a large bike shop cant figure it out

shimanobottombracket

My Mavic Cosmic's been making a weird sound. The Mavic "Howl Of Death" would be extreme, but it sounds like a metallic rubbing sound, not very loud but very annoying. Tried servicing the freehub as per this vid:

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

I also tried the rear wheel off an old road bike and the noise went away. However on my Cosmic, its when cycling at a moderate pace when the sound manifests. As far as I can tell, it doesn't happen when I stop pedaling, but it's possible I can't hear it over the normal clicking sound bicycle hubs make when I do that.

Got fed up and took the wheel into a major bike shop, only for them to say they couldn't replicate the sound or find the cause of the noise. Bit buggered as to where to go from here. How can a faulty wheel (or hub) only display symptoms in 1 bike and not another? If it isn't the wheel, why does the problem go away when I use an old wheel? The issue also displayed on both front chain rings aswell as multiple sprockets on the cassette. If its a chain wear thing, wouldn't I get chain slipping/jumping issues? It is my 3rd chain on this cassette, but the problem seemed to manifest suddenly, or I only noticed it suddenly and this chain has been on a while. Was considering changing the chain and all sprockets after this one wore out but I wont spend another penny until I'm sure what the cause is.

bungalballs

Could be many things.

Are your skewers nice and tight? And clean? Are your dropouts clean where they contact, no loose paint etc?

Try putting a tiny bit of lube on the spokes of your rear wheel at the point they cross each other.

The Rookie

Having had the Mavic Screech of death it certainly sounds like what you have is NOT that, if you have heard it you can't mistake it for anything else, finger nails on blackboards are still worse.......just!

Not a part of the wheel rubbing the frame or an axle spinning in the frame?

olly22

I bought a pair of the same wheels about a year ago and have the exact same issue! Almost sounds like a brake pad scuffing. It comes and goes and strangely seems dependent on the weather. I have taken them apart, changed the tyres, changed inner tubes, serviced freehub, lubed quick release etc etc

Doesn't seem to make a single bit of difference to them rolling though. One thing that did oddly make a difference was to put a piece of electrical tape over the small circular holes in the carbon fairing (presumably there to drain water) and wrap a few turns of it around where the inner tube valve pokes through.

in the end my conclusion was that it was something acoustic as the wheel turned.

Just enough to really be annoying on a long ride though!

pirnie

I had a similar sounding, unexplained noise from my Ksyrium Elites, kind of like a grating/rubbing sound. For me it was from the front but could happen from the rear too. I eventually tracked it down to the hubs.

The plastic covers on the bearings (which you screw in and out for the bearing adjustment, QRM+ or whatever it's called) have a raised serial number moulded into the bearing side. When the wheel roatates, this rubs against the seal on the bearing causing the noise. Initially I tried to fix this by putting some grease on the inside of the plastic cover which worked for a while but the noise just came back. In the end I just took some sandpaper to the cover and removed the raised lettering. Since then, no noise.

I don't know if these wheels have the same hub bearing adjustment as the Ksyrium Elites do, but if they do I'd suggest you give this a try.

shimanobottombracket

Olly22 wrote:

I bought a pair of the same wheels about a year ago and have the exact same issue! Almost sounds like a brake pad scuffing. It comes and goes and strangely seems dependent on the weather. I have taken them apart, changed the tyres, changed inner tubes, serviced freehub, lubed quick release etc etc

Doesn't seem to make a single bit of difference to them rolling though. One thing that did oddly make a difference was to put a piece of electrical tape over the small circular holes in the carbon fairing (presumably there to drain water) and wrap a few turns of it around where the inner tube valve pokes through.

in the end my conclusion was that it was something acoustic as the wheel turned.

Just enough to really be annoying on a long ride though!

Thats exactly how I would describe it, ruled out by opening the brake's quick release and the noise still being there. However the noise did manifest suddenly at the start of a ride. Your explanation also seems to fit my scenario as I have to do about 17mph to notice it. However I cannot tell if it happens only when pedaling due to the noise of the pawls when yo stop pedaling. For it to be an aero thing the noise would be there when I stopped pedaling aswell. Maybe I will try spinning the wheel when my bike is upside down when I get a chance next.

Are those carbon fairings removable?

pirnie wrote:

I had a similar sounding, unexplained noise from my Ksyrium Elites, kind of like a grating/rubbing sound. For me it was from the front but could happen from the rear too. I eventually tracked it down to the hubs.

The plastic covers on the bearings (which you screw in and out for the bearing adjustment, QRM+ or whatever it's called) have a raised serial number moulded into the bearing side. When the wheel roatates, this rubs against the seal on the bearing causing the noise. Initially I tried to fix this by putting some grease on the inside of the plastic cover which worked for a while but the noise just came back. In the end I just took some sandpaper to the cover and removed the raised lettering. Since then, no noise.

I don't know if these wheels have the same hub bearing adjustment as the Ksyrium Elites do, but if they do I'd suggest you give this a try.

Interestingly, I believe they do have some sort of bearing adjustment. I will check this out aswell.