Park Tool HCW17 Head-Gear Lockring Wrench, Blue — Dual-Radius Hooks for 41–44mm Rings

The Park Tool HCW17 is a two-radius head-gear lockring wrench designed to securely engage 41–44mm lockrings and compatible single-speed cassette hub rings.

Compact and purpose-built, the HCW-17 gives bike mechanics and home technicians a precise tool for installing and removing common head-gear lockrings found on many headsets and some single-speed hubs. Its dual-hook design ensures a snug contact with either 41–42mm or 43–44mm outside-diameter rings, reducing slippage and damage during service.

What makes the HCW17 reliable for headset lockrings?

The wrench uses two different radius hooks machined to match common lockring profiles, preventing rounded edges and poor engagement. Its small footprint reaches into tight headtube areas and holds rings firmly while you torque or loosen them.

• Dual-radius hooks for precise contact with varying ring sizes
• Narrow profile fits recessed headsets and tight frame clearances
• Stiffer metal construction resists bending under torque

Which lockring sizes and hub types does it fit?

The HCW-17 is sized for lockrings with outside diameters of 41–42mm on one hook and 43–44mm on the other, covering the majority of head-gear lockrings. It also works on single-speed cassette hubs that use externally notched lockrings, giving the wrench some cross-compatibility beyond headsets.

• Hook A: fits 41–42mm outside-diameter lockrings
• Hook B: fits 43–44mm outside-diameter lockrings
• Also fits single-speed cassette hubs with external notches

How should I use the HCW17 without damaging parts?

Align the appropriate hook so it fully mates with the lockring’s notches or outer edge before applying force; avoid partial engagement. Use steady, controlled torque and support the opposing components (like the cone or bearings) to prevent stress on adjacent parts.

• Select the hook matching the ring diameter for full contact
• Hold the hub or headset steady to prevent slippage
• Apply controlled turning force; avoid hammering the wrench

How does the HCW17 compare to multi-tool alternatives?

Specialized single-purpose wrenches like the HCW-17 typically offer a cleaner fit and less risk of rounding than generic adjustable tools. While a multi-tool is handy for on-the-road fixes, the HCW-17 provides better leverage, accuracy, and durability for workshop maintenance.

• Better hook geometry for specific lockring sizes versus generic jaws
• Stronger, single-piece construction for repeated shop use
• Smaller profile for accessing recessed rings compared with bulky tools

Who is this for: The Park Tool HCW-17 is ideal for bicycle mechanics, weekend wrenchers, and anyone who services headsets or single-speed hubs regularly. If you want a compact, precise wrench that reduces the risk of ring damage and fits common 41–44mm lockrings, this tool is a practical addition to your toolbox.