They do, because i bought one a while ago :D. You have to take it apart and mess around all day to get it off.
Loctite it, itll never come loose, and it takes 5 minutes literally. I've done it on about 5 claws :D
Just read youd loctited it before but it didnt work.......sooo..........buy a brand new standard acs claw from tarty bikes. Take the lockring off carefully making sure you dont make any ball bearings fall out etc etc. take off the little washers inside. Clean the thread on the lockring, and the thread on the freewheel with petrol or similar, making sure that you dont get any on the ball bearings. Wipe with a cloth and leave to dry. If you're using petrol itll evaporate so its easy. Put a moderate amount of loctite on the LOCKRING ONLY. If you put it on the freewheel aswell you risk getting it on the bearings. Screw it on, leave for around an hour, put it on the crank, go ride. It won't come loose. If it does, youve not done the above properly, because mine never failed me :P .
Sorted!