I have a fairly old shimano hyperglide cassette that I use for my single speed. When I was out tonight I noticed a grinding noise and could feel it as well coming from the cassette. I checked the cones to make sure they were not loose ot too tight, and that I have all the bearings (I greased them last week and thought maybe I messed one). The noise is louder when I coast, but is constant. It gets louder and I can feel it more at a certain point in the wheels rotation. The cassette body is tight to the hub and has no free play or side to side motion. I don't know for sure how old the cassette is, I bought it used on a bike 4 years ago. Could it be that the cassette is worn out internally? I don't know enough about this problem to be certain. And if so what are my options, or what else should I check for? .