Weird sound from rear

[Florian]

I have a Corratec MTB. Everything was fine, but 2 months ago i took it to bike shop and changed its tires. Since that day i have a very strange problem.

Sorry but English isnt my native language, so i will do my best.

Lets say im pedaling, and i suddenly stop pedaling and start floating. A sharp sound comes from rear of bike. A continous sharp sound as if something is rubbing. If i start pedaling at this time, the sound goes away. However if i dont, the sound keeps until the bike stops.

1) It does this sound only on uneven surface. It doesnt do it on asphalt.<br />
2) It does not always do it. Even if i start floating on uneven surface it sometimes does it.<br />
3) I have disk brakes. The bike shop tried to understand the sound, he even disattached the brakes but the sound was still there.

Thanks

[Florian]

Sorry, floating should be "coasting"

[Bill]

I know this post is like 7 months old, did the bike shop look at the cassette to make sure it wasn't something not installed correctly?