Cassette Wrench 11/12t

A chain whip is the standard cassette-holding tool. It also wraps around a greasy chain, fights the chain's tendency to walk off the cog, and leaves your hand smelling like a drivetrain. The Cassette Wrench 11/12t is the chain-free version of the same job: three steel pins engage the small cog directly, the 350 mm handle gives you the leverage to break a stuck lockring, and you can put the tool back in the drawer without wiping it down.

The three pins are the design call that matters. A chain whip relies on a wrapped-chain length around the cog teeth; friction plus geometry; to hold the cassette still under load. That works, but it depends on the chain seating cleanly in the cog valley, which it doesn't always do on cogs that have been ridden until the teeth are uneven. The 11/12t wrench's three pins drop into three separate tooth gaps and grip the cog from inside the gap rather than around the outside. The grip stays positive whether the cog is fresh or already shaped by a worn chain.

The pins are notched to keep the tool from popping off under the kind of force a 350 mm handle delivers. We've put a hand at the end of the handle on cassettes torqued well past spec, and the pins stay seated.

Three versions for three cog sizes

The Unior cassette-wrench family covers three small-cog ranges. The 11/12t version here is sized for cassettes with an 11- or 12-tooth small cog; the dominant configuration on modern Shimano and SRAM HG cassettes from 9-speed through 12-speed, and Campagnolo cassettes through 12-speed. The other two:

• The Cassette Wrench 13/14t is for cassettes with a 13- or 14-tooth small cog; older derailleur cassettes, some touring builds, and a number of BMX-style cassettes.
• The Cassette Wrench X Range is for SRAM AXS X-Range cassettes with a 10-tooth small cog. Neither this 11/12t version nor the 13/14t reach that small.

If you're not sure which small cog you have, count the teeth; the cassette's spec sheet will list the cog range as 10- or 11- or 12- something, and the first number is the small cog.

Compatibility

• Shimano HG cassettes with 11- or 12-tooth small cogs (most current road and MTB 9- through 12-speed)
• SRAM HG cassettes with 11- or 12-tooth small cogs (XD and XDR included)
• Campagnolo cassettes with 11- or 12-tooth small cogs
• Microshift and Sunrace HG cassettes with 11- or 12-tooth small cogs
• Not for 10-tooth small cog cassettes (use X-Range)
• Not for 13- or 14-tooth small cog cassettes (use 13/14t)

Specs

• Three pin engagement on the small cog
• Notched pins for slip resistance under load
• 350 mm handle for full lockring break-free leverage
• Sized for 11- or 12-tooth small cog cassettes
• Article number: 1670/2BI-US

Built in Zreče, Slovenia

Unior has been forging hand tools in Zreče since 1919, and is the official technical partner of multiple World Tour and downhill teams. The cassette wrench design is the kind of detail that comes out of a professional service environment; a chain whip works, but it doesn't work better the longer you've been wrenching, and the pin-engagement version is faster, cleaner, and easier on the cog teeth. The three Unior cassette wrenches together cover the full small-cog range from 10t up to 14t.

Pro tip from our mechanics

If you're working through a stack of cassettes; wheel building, batch service, a season's worth of swaps; the time the cassette wrench saves over a chain whip adds up. The pins seat in two seconds where a chain whip takes ten to wrap and seat, and there's no chain-management between cassettes. Pair the wrench with the Integrated Cassette Lockring Wrench 1670.8/2BI-US and the swap is two motions: chain whip side and lockring side, both with handles long enough to break torque without a ratchet. The cassette-replacement workflow has more on which holder fits which drivetrain: When and how to replace your cassette →