i just got this flip flop hub with a freewheel and sprocket from Boy Go Fast today and Gee Whiz what a piece of crap it is. the 36t steel sprocket is attached to a left-side freewheel with junk hardware, and the freewheel itself feels about as smooth as a ohio forge ratchet wrench that was left out in the rain for 2 years. seems like if i rode it on one of my bikes, it would cease being a freewheel after a few miles and lock up. the axle nuts don't even fit. i mean, they thread on, but they wobble like they're one size too big, and i think they're made outta, i dunno, something. melted beer cans. the bearings in the hub...pfffft. the whole thing sucks. don't buy one.