Last week while riding some fast downhills in coast mode I felt a vibration from the rear of the bike and presumed it to be the rear hub. It happened a few other times and only at a high speed.

When totally off the bike when I lift the rear wheel off the ground and spin the wheel backward there seems to be enough resistance in the hub that the crank and peddles actually turn over. Is my hub trashed or is it repairable. I do not notice a problem when the I am on the bike and supplying power.

Suggestions requested.. Thanks curtwally

don't know what that is, but...

you'd better hope so...if this didn't happen, you wouldn't be able to pedal. do you mean when you spin the wheel forward?? because that would be weird.

yup maybe I mean forward. If I lift the rear wheel up off the ground and spin the wheel forward toward the front of the bike it has enough resistance that the entire chain crank gear spins as well. On all our other bikes the wheel just spins when I do this. thanks curtwally

You could post in the mechanic's forum. It sounds to me that the paws are getting hung up. That causes the pedals to turn when the wheel is spun. What I cant explain is the vibration. Remedy is to lube up the freewheel hub. Do you over clean the cassette? This can lead a dry freehub and the paws get stuck. This happen to me and I would get chain suck up. In my case the hub was not serviceable so I needed a new hub. So I don't near the cassette with the orange cleaner any more.

Mavic hubs have a plastic bushing inside the freehub that need to be lubed, and replaced after about 5000 to 15000 miles. You can buy a new bushing for about $15 from ebay and their is a video on youtube on how to install. I've done 2 hubs, took about an hour. Sounds like you need to replace yours

It's hard to diagnose without opening it up, but I had something similar happen to a Ringle hub about 5 years ago while mountain biking. Basically, one of the pawls that usually ratchets, had become broken and jammed, so that I couldn't coast without the hub making a massive metal grinding noise.

I don't do hub or headset work, so my mechanic took hub body apart, replaced the broken pawl and I've been using the hub ever since (even though I don't really use those wheels anymore).

Looks like this guy has pictures of his broken hub.

I had this problem. it happened worse when it was cold out... turns out I just needed to get into the reehub and relube the pawls.... didnt have to replace the pawls.

it mostly happened on high speed descents when coasting, and would go away when I would pedal (and reengage the pawls). the noise was something between a buzzing and vibrating noise... definitely not grating, but scary.

The hub just needs some service. It's easy to do yourself you just need a 10mm and a 5mm Hex wrench. It isn't even necessary to remove your cassette to open the hub. (but it makes it less messy. )
- Just pop out the plastic end-cap on the left side of the wheel (Where the QR goes through) and put in the 10mm hex wrench.
- Put the 5mm hex wrench in the right side axle and open while while holding the left side.
- Take out the right side axle and carefully slide off the freehub.
- Make sure you do it slowly and above a table or something because the two pawls might want to jump out.
- take out the pawls or let them sit. (You can get replacements from your lbs that sells mavic.)
- Pull out the left side axle from the left side.
- Clean and lube everything. Check if the bearings are all still smooth. (there are 3 of them! there is 1 in the freehub and 2 in the hub)
- Put everything back together in reverse order with some thin lube.

Once you learn how to do this it becomes a 5minute job. I do this once or twice a month on my wheels. Keeps them from wearing out and problem free.

Greets!

loose bearings made my shimano r550 rear wheel vibrate. They make combination solvent/lubes that should work without taking it apart. If thats not illegal in the eyes of a master mechanic.

Thanks,

Yup it worked just as you said it would and is fairly simple. It did take me and my buddy a few more than 5 minutes. Problem solved with just a simple cleaning of pawls, springs, and surfaces. Thanks again. We did take the cassettes off to make it easier to see what was going on.
curtwally