Bottom Bracket Wrench 12 notch

Praxis Works M30 external bottom brackets use a 12-notch interface that doesn't match the 16-notch Shimano-pattern wrenches that cover most of the current market. The notch diameter sits at approximately 46.3 mm. A 16-notch wrench skates across the cup; a 12-notch tool sized to the wrong diameter rounds the notches on the first hard turn. The 1671.9/2DP is the dedicated wrench for this specific interface.

How it's used

Mount the wrench's notched face over the BB cup so all 12 notches mesh fully with the cup's pattern. Press the wrench home before applying torque; partial engagement is what rounds notches on press-fit-threaded crossover designs like the M30.

The wrench body has a 1/2″ square drive on the working face for driving with a torque wrench or a 1/2″ ratchet. That matters on M30 cups: Praxis specifies an install torque, and a torque wrench is what hits it cleanly.

Drive side on most M30 cups is right-hand thread (loosens counter-clockwise); non-drive side is normally threaded. Verify against the BB's marking before applying force; some M30 generations differ from the standard.

Compatibility

• Praxis Works M30 external bottom brackets
• Other external BBs with a 12-notch pattern at approximately 46.3 mm diameter
• Not compatible with 16-notch external BBs (Shimano Hollowtech II, SRAM GXP / DUB); for those, use the 16 Notch External Bottom Bracket Wrench (1609/2BI-US).

Specs

• Material: premium flex plus carbon steel
• Surface finish: chrome-plated to ISO 1456:2009
• Notch pattern: 12-notch, sized for ~46.3 mm OD cups
• Drive interface: 1/2″ square on the working face for torque wrench or 1/2″ ratchet

Built in Zreče

Unior has been forging hand tools in Zreče since 1919, and is the official technical partner of multiple World Tour and downhill teams. The 1671.9/2DP exists because the modern BB market hasn't converged on a single notch standard; threaded crossovers like Praxis M30 are common enough that a dedicated 12-notch wrench earns its place on the wall, not just a generic spline tool.

Pro tip from our mechanics

Praxis M30 cups can creak under load when the cup-to-shell interface dries out. Before reinstalling, clean the threads thoroughly and apply a thin film of grease or anti-seize. A dry interface is the most common cause of M30 BB creaks, and the fix is exactly the workshop step that takes thirty seconds at install time and ninety minutes if it's missed.

For the full BB removal-and-reinstall procedure including thread cleaning and grease application: Replace or clean your bottom bracket →.