The Wolf Tooth Oval Direct Mount Chainring for Shimano is a 32 tooth oval ring that mounts straight to Shimano 12 speed direct mount mountain cranks.

What it's for

This ring replaces the stock chainring on a Shimano 12 speed direct mount crank when you want an oval shape or a different tooth count. An oval ring changes the effective gear size through the pedal stroke. Wolf Tooth describes its oval shape as PowerTrac.

How it works

Drop-Stop tooth profile: The teeth alternate wide and narrow to match the wide and narrow gaps in a chain. That keeps the chain centered on the ring. Wolf Tooth says the wide teeth spread the load for longer wear and the narrow teeth leave room for mud to clear.

Compatibility

• Fits: Shimano XTR M9100, XT M8100, and SLX M7100 series 12 speed cranksets
• Offset: Wolf Tooth makes this ring in 0 mm offset and Boost (3 mm offset) versions. Wolf Tooth says the chainline matches Shimano's original for each crankset. Check the package to confirm which offset you have.
• Chain: depends on the tooth profile marked on the ring. See the three profiles below.
• Drop-Stop A: all 9, 10, and 11 speed chains, plus 12 speed SRAM Eagle, Connex, and Wippermann. Not for Shimano HG+ 12 speed, KMC 12 speed, SRAM Transmission flattop, or Campagnolo 12 speed.
• Drop-Stop B: all 9, 10, and 11 speed chains, plus 12 speed SRAM Eagle, SRAM flattop (road and Transmission), Connex, Wippermann, and Campagnolo. Not for Shimano HG+ 12 speed, KMC 12 speed, or Campagnolo 13 speed.
• Drop-Stop ST: Shimano HG+ 12 speed and KMC 12 speed chains only.
• How to check yours: Look at the crank model stamped on the inside of the arm, and match the tooth profile on the ring to your chain brand and speed.

Specs

• Teeth: 32t, oval
• Weight: 65 g
• Material: 7075-T6 aluminum
• Made in: USA (machined in Minnesota)

You will also need

• Chainring lockring tool: Shimano direct mount rings are held by a lockring. Wolf Tooth's page does not list the tool or torque, so follow Shimano's crank instructions or have OMG's bike shop install it.