Originally Posted by
Chris O
Got it. It's coming from the rear wheel. It is amazing how a little grinding noise from the hub due to bearings or mis-adjustment is being amplified by the frame. It sounds like the carbon is fracturing apart! Now, onto the hub....
Just want to reiterate...you said you are hearing the noise when you're NOT pedaling. Therefore...how/why could it be the pedals or BB? Usually, when cones/bearings have gone bad the "popping" or grinding noise they make won't be heard when spinning the wheel when the bike is on the work stand. But, as you point out, will be heard while actually riding. Take the cassette off, disassemble the rear hub, and check the cones/bearings. I will bet they're pitted and need to be replaced.
Dan