Direct Mount Chainrings for Bosch E-Bike Motor
BG4-34-ST
Pairs well with
Direct Mount Chainrings for Bosch E-Bike Motor
Free WT-1 With Chainring Purchase
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Promotion Expires 12-31-2024
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.
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55mm chainline
Tech Specs
Weights: 32t • 87g | 34t • 95gMaterial: 7075-T6 aluminum
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:
Not compatible with 12s Shimano HG+, 12s KMC, or 13s Campagnolo chains |
All 9s, 10s, and 11s Chains 12s Chains:
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:
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 |
 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 |
 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 |
*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.