Strange Rubbing Sound From Rear Wheel

[zap602]

On occassion, I have been hearing this strange rubbing sound coming from my rear wheel recently. I had the rear hub overhauled and the pawls were replaced even though it didn't need them. I thought the tire may be rubbing on the seat stays, but I put tape in the suspected area and there was no indication of rubbing. The sound happens when coasting, but stops when I resume pedaling.

Any ideas?

[TiRyder]

Need more Info:

What kind of wheels? Specifically the hubs.

Do you have disk brakes or rim brakes?

Under what circumstances does the sound occur?

It is a hardtail or Full Suspension Bike?

[mtbGreg]

The rear wheel on my back-up bike makes a noise because it is out of round and has loose spokes as a result of a kink in the rim. Any chance you have loose spokes leading to a flexing rim?

[FIX_BKS]

On occassion, I have been hearing this strange rubbing sound coming from my rear wheel recently. I had the rear hub overhauled and the pawls were replaced even though it didn't need them. I thought the tire may be rubbing on the seat stays, but I put tape in the suspected area and there was no indication of rubbing. The sound happens when coasting, but stops when I resume pedaling.

Any ideas?

I assume, if you've had a hub overhaul done, that the plastic spoke protector has been removed? If not, make that step 1.

If so, it sounds like it's definitely associated with the free hub body since it's only happening when coasting. Have you tried removing and reinstalling the cassette? Spin the freehub while the cassette is off and see if it's dragging...

[jabberwocky]

If the freehub is a little sticky, its possible that the chain is losing tension on top when you coast (the rotational motion of the wheel applies slight pressure to the freehub). If the chain gets slack, it can rub the tire as it rotates. All my King hubs did this when new, and sometimes still do in very cold weather. Its easy to spot though: test ride the bike, coast, and look back to see if the chain is slackening on top.

I would also check that all the drivetrain parts are tight. Its possible a loose hanger/derailleur/wheel/crank/something could be shifting when you coast, causing something to get close enough to the wheel to rub.

[tuba_transport]

like a zing sound?

[zap602]

It's a Mavic hub.

Disc Brakes - Avid BB5s

Sound happens when coasting. Started as the weather got colder.

Bike is a full suspension. SC Superlight.

Had the rim checked out when I had the hub rebuilt. Assume the spokes are fine.

I did notice the chain slack on top when coasting. Never thought to look and see if it was rubbing against the tire.

The sound is definitely like a tire rub.

Everyone, Thanks for the input. I'll check all out and let you know what I find.

[tuba_transport]

I did notice the chain slack on top when coasting. Never thought to look and see if it was rubbing against the tire.

That is the pawls not releasing as easily as they should. Maybe things are too tight right now? Cold weather will certainly thicker up the grease. Also new parts might have tighter tolerances. As Jab pointed out, this is obvious on new King hubs.

Hopefully things will loosen up for ya.

[TiRyder]

It's a Mavic hub.




Thats what I thought it might be. I have seen, or heard, this before. Its probably the bearing seals being dry or gritty

Use two 4 or 5mm (I forget because its been a while since I did mine) allen keys to loosen the axle on both sides, drop some lube or grease on the oring on the axle end pieces. Next loosen the nondrive side bearing adjustment and drop some light lube on the bearing seal. Mavic makes a bearing adjustment tool which you turn the external bearing (that has the small holes in it next to your bikes dropouts) that you place on the hubs and tighten while the wheels are on the bike. If you bought the wheels new you should have received one of these tools. It is usually the non drive side that causes the rubbing sound because there is a little rubber seal in there that gets dry or crud in it and causes the sound.

After you have dropped the lube in there, the axle should be tightened snuggly, but when you tighten the axle pieces, the bearing adjuster might also tighten and cause the wheel to not spin freely on the axle, so make sure it is backed off a little. Put the wheel back on the bike and use the bearing adjustment tool to re-adjust the bearing play so that the wheel spins freely, but without any slop. I would try snugging it slightly, then back off a little, maybe a quarter turn.

Hope that helps

[rizetech]

^ phil tenacious oil is superb for quieting hubs, and it's thick so it lasts pretty long (cartridge bearing only of course)

[zap602]

Thanks for all the replies.

Checked for chain rub and that was not the problem.

Definitely think it is the pawls not fully disengaging when coasting, since that is the only time I hear the sound. Talked with the guys over at Race Pace who did the overhaul, and they seem to think the combination of cold temps and sticky grease could be causing the problem.