Strange squealing when I stop pedaling
I recently bought a new bike and the shop switched all of my 2-year old Shimano Ultegra components and FSA SL-K cranks over to a new frame (not sure if this is relevant). I ride 2 year old Mavic Ksyrium ES's.
When I ride, I occasionally get a really loud squealing noise that seems to only happen when I stop pedaling. A good example is that while riding up hill, it NEVER happens, but then going back down hill it seems to start squealing when I coast. As soon as I pedal, the noise disappears. It doesn't happen every time I coast, but does happen quite frequently. It's tough to describe, but it is a very loud squeal. It's not a creak, or a small squeak, and it never happens while pedaling.
My brake position looks fine. I just had the bottom bracket re-sealed, but the noise is still there.
Sounds like the freehub. Try getting it to make the noise while freewheeling on a bike stand, and listen to where it comes from. I bet it's the back wheel. I think the Mavic freehubs can be rebuilt, but I know they can be replaced. Work on the wheel bearings while you're in there, too.
Thanks for the input. I think you were right. I couldn't duplicate it on a stand (it may have something to do with my weight on it too), but I did immediately notice that when I let go of my pedal, the cranks continued to rotate. So, I swapped out my rear wheel and had a 40 mile squeal free ride today. I'm going to re-build the rear hub on the ES and see what happens.
Call me The Breeze
You need to pull off your freehub and put a few drops of oil in there. Mind the pawls and springs when you open it up!