have just done a freewheel conversion to replace coaster i had no instructions so guessed my way through after a number of attempts on my last go i ended up removing inner hub shims and spring then put back together leaving only the threaded cone thingy in the centre which the new freewheel sprocket and new hub winds onto put back on bike and was lookin good till i took for spin down road when as tearing at around 10 mph the crank span round and im left grazes and bruised knee ouch,it appears ive fooked up coz the freewheel is unwinding itself from inner hub what have i done wrong any ideas i may have to bring to ramp see if anyone can shed light