Fixed-gear lockrings require a specific wrench that most toolboxes don't include. The threading is reverse (left-hand) to prevent the lockring from loosening as you pedal, and the notches are spaced differently than cassette lockrings or bottom bracket cups. Park Tool's HCW-17 fits those notches precisely, giving you the leverage to properly secure a track cog without damaging the lockring or slipping mid-turn.

The wrench works on standard fixed-gear lockrings with notch spacing of 35.3mm between engagement points. That covers the lockrings you'll find on track hubs, flip-flop hubs, and single-speed conversions using threaded fixed-gear cogs. The stamped steel construction handles the torque these lockrings require—you're essentially locking the cog against the hub's threads, and that connection needs to be tight enough that pedaling force in either direction won't work it loose.

Installation is straightforward once the cog is threaded on: the lockring threads in the opposite direction (counterclockwise to tighten) and cinches against the cog. The HCW-17's two-pin engagement keeps the tool seated in the lockring notches while you apply force, which matters because these lockrings sit in a recessed area where a slipping tool can gouge the hub shell or your knuckles.... Read More