I recently acquired a Nukeproof hubbed wheelset for cheap and I now realize why. These things are supposed to have a collar with a locking screw that tightens onto the axle and this is what presses against the drop-out to hold the wheel onto the bike. Unfortunately, mine didn't have them. Anyone know where I can get such a locking collar? I ordered a set from some fastener company, but they ended up being too deep. Any other fixes would be welcome.

Thanks