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The Wolf Tooth Direct Mount Chainrings for Bosch E-Bike Motors are compatible with all Boost and Super Boost bikes that use the Bosch Gen 4 E-Bike Motor. This continues the Wolf Tooth product line of Drop-Stop chainrings for e-bike motors. Direct Mount Chainrings for Bosch E-Bike Motors are machined with 7075-T6 aluminum at Wolf Tooth in Minnesota, USA.


Compatibility

  • Chainring is compatible with most bikes that use the Bosch Gen 4 e-bike motor. Not compatible with Pivot bikes using Superboost chainline.
  • Drop-Stop B tooth profile is compatible with almost all 9-, 10-, 11-, and 12-speed chains, including SRAM Transmission T-Type
  • Drop-Stop ST tooth profile is compatible with Shimano HG+ 12-speed chains and KMC 12-speed chains.
  • 55mm chainline
 
 

Tech Specs

Weights: 32t • 98g    | 34t • 105g 
Material:   7075-T6 aluminum
Made in the USA


Wolf Tooth is committed to provide the most precision components possible and has three different tooth profiles for optimal performance based on your chain type.


Tooth Profile

Tooth Profile

Drop-Stop® B

Drop-Stop® A

Drop-Stop® ST

Chain Compatibility

Chain Compatibility

All 9s, 10s, and 11s Chains

12s Chains:

  • Connex
  • Wipperman
  • Campagnolo
  • SRAM Eagle
  • SRAM Road and Transmission (T-type) Flattop chains

Not compatible with 12s Shimano HG+, KMC, or 13s Campagnolo chains

All 9s, 10s, and 11s Chains

12s Chains:

  • SRAM® Eagle
  • Connex
  • Wippermann

You can use Drop-Stop B when Drop-Stop A is not available*

Not compatible with 12s SRAM Transmission (T-Type) and Road Flattop, 12s Shimano HG+, 12s KMC, 12s Campagnolo, or 13s Campagnolo chains

12s Chains:

  • Shimano HG+
  • 12s KMC

Not compatible with all other chains

Details

Details

Tooth shape is nearly identical to Drop-Stop A, but has narrower teeth. Valley between teeth is deeper to accommodate larger rollers on Flattop chain. Outside faces of narrow and wide teeth touch chain to guide alignment.

Drop Stop B Chainrings navigate_next

The original Drop-Stop tooth profile. The wide teeth are wider than Drop-Stop B. Outside faces of narrow and wide teeth guide chain alignment.

Drop Stop A Chainrings navigate_next

Narrower teeth than Drop-Stop A. Wide teeth use Symmetric Trapezoidal (ST) profile to match extended inner edge on chain to create alignment (outside faces of wide teeth do not touch). Interaction of narrow teeth and chain are similar to Drop-Stop A and B.

Drop Stop ST Chainrings navigate_next

*We are in the process of migrating most Drop-Stop A to Drop-Stop B to make them compatible with  SRAM Road and Transmission (T-type) Flattop chains.