# Buzzing/vibration from rear wheel



## 65mph12 (Jan 31, 2012)

I noticed a buzzing/vibration coming from my rear wheel when going downhill at about 12mph+. It stops when I lock the rear, but starts up again right away once the wheel resumes spinning. I only notice it at the higher speed while coasting. The wheel is mounted tight and spins freely like normal. I'm thinking bearings/lube. The brake assembly seems ok.

I searched the forum for an answer, but other problems people had seemed to be either constant or intermittent noises/vibrations.


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## SS-Dad (Oct 17, 2006)

*Could be a few things...*

A major culprit maybe a loose wheel reflector (if these are installed). Certain ones that mount on a single spoke can move or rotate - causing noise at unspecific speeds, also stopping when you stop.

Check any and all bolts (a good idea before a ride anyway) for tightness.

Make sure your rear quick release is not overly tight. If it is, it could be binding the wheel bearings - in turn causing a vibration or shudder that may present itself as a buzzing.

Sometimes rubber dust caps mounted on the ends of the axles can chirp and squeak when wheels are installed too tightly in the dropouts. Though, this doesn't sound like what you have described.

Also, check the spoke protector or pie plate (again, if installed). Loose or partially broken pie plates can and will cause all sorts of noises.

If you can, take a six pack of GOOD beer to your local bike shop and ask nicely if a mechanic can find or diagnose the problem, if they have a second. Ask nicely and be patient.

Hope this helps some.


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## 65mph12 (Jan 31, 2012)

I stopped the bike and flipped it to check the QR for adjustment/security, the hardware seemed ok. I'll check the pie plate though.

My LBS is pretty good. I brought the bike in recently for a squeak. The tech adjusted my brake assembly in about two seconds and the squeak went away. Amazing how simple some problems can be.


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## Sarguy (Sep 25, 2010)

I had a similar condition with my rear tire. Turned out to be the ply inside the wall of the tire was separating, this caused a hardly noticeable bulge in the side of the wall. Made a noise like I had a wet leaf stuck to the tire. Noise continued when I wasn't pedaling, so I knew it was not the gears. Once I opened up the rim you could clearly see the separation on the inside. Weird, the tire was tubeless ready and I was using Stans. Don’t know why it failed. Only 967 miles on it. Replaced the tire and all is well.


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## EABiker (Jun 24, 2004)

Any chance your rear suspension is flexing and allowing the brake line to rub on your tire tread?


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## 65mph12 (Jan 31, 2012)

All lines are clear of the rear tire. 

The vibration is strong throughout the whole frame. I can feel it in the bars. It stops below ~ 10 MPH or so.


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## xenon (Apr 16, 2007)

It may be overtightened bearing cones (if your bearings are not of industrial variety). Or the cones/races may be worn out (likely, due to overtightening, if the wheel is not old). 
Or something, like, say, a piece of string stuck in between the cassette and spokes.


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## James_spec (Jul 28, 2011)

Have you true your wheel? Might want to look into that.


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## s0ckeyeus (Jun 20, 2008)

Your kickstand is rubbing against the tire. :lol:


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## 65mph12 (Jan 31, 2012)

James_spec said:


> Have you true your wheel? Might want to look into that.


I changed the tire last week, and spun the wheel to check the bead. The wheel is straight as an arrow.



s0ckeyeus said:


> Your kickstand is rubbing against the tire. :lol:


LOL


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## thomllama (Oct 3, 2007)

got a buddy who can ride behind you? might be able to see something. 

gunna have to say, if you can feel it through out the bike, it buzzes, it's likely a bearing issue.

I would check around the cassette for string, leaves, a small twig... and if you still have the pie plate it could very well be it when the speed gets enough for air turbulence to effect it.. kinda a a hard one to figure out with out seeing it.

does it both coasting and pedaling?


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## 65mph12 (Jan 31, 2012)

I cleaned my cassette when I changed my tire, so it was real easy to see that it was clear. I've only noticed it while coasting at speed. It stops when I slow to around 10 mph or so. The pie plate seems tight. I'm going to drop by the LBS and see what they think.


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## aztrail (Sep 27, 2011)

was it happening before you changed the tire recently?


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## 65mph12 (Jan 31, 2012)

It happened once but not as persistent. The mech at the LBS did mention that new tires can sometimes cause vibrations due to the tall & rigid knobs along with over-pressurization.

He checked the bearings, which were good, and removed the pie plate. I did clean the pie plate when I changed my tire, so maybe I loosened it enough for the wind to affect the plate when I got some speed built up. 

He didn't charge me for the diagnosis/adjustments, so I bought a QR seat post clamp. Great shop.

When I got home, I rode it up to 25 mph and there was no buzzing/vibrations. I never would have guessed the pie plate could make the bike resonate like it did.


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## aztrail (Sep 27, 2011)

65mph12 said:


> When I got home, I rode it up to 25 mph and there was no buzzing/vibrations.


Great news!


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## Dune (Jul 26, 2012)

When I first got my bike, I had knobby tires. When I was coasting at higher speeds downhill. There was a buzzing sound. Eventually, I changed the tires to slicks and the buzz is barely noticeable.


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## Tone's (Nov 12, 2011)

Do you think you might have got a Bee caught in the back tyre before you put it on, that could be causing the buzzing, cheers


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## 65mph12 (Jan 31, 2012)

*Update: Solution found*

I've been meaning to update this thread for awhile now, and figured I better do it before the end of the world today.

The noise eventually came back and was much more persistent than before. I also noticed the noise was even more obnoxious when I would pedal backwards. At this point, I knew it had to be the hub.

Long story short, I talked with a guy on the trail about it, and he said it sounded like the "Mavic Growl".

I looked it up when I got home and came across this thread: http://forums.mtbr.com/wheels-tires/freehub-problem-820488.html

Easy to fix, and my hub sounds better than ever.


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## shibiwan (Sep 2, 2012)

Yes, I get the same sounds of protest from my Mavic CrossMax ST. I made a replacement bushing and re-lubed it and the vibration went away.

http://forums.mtbr.com/wheels-tires/diy-mavic-freehub-rebuild-824126.html

Found out after the fact that you can get replacement bushings for the freehub. LOL

Working on a ball-bearing freehub insert that will hopefully fix this once and for all.

-S


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