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- dafuli01@ebikeserviceparts.com
Bafang BBS M33 bottom‑bracket mounting lock ring, outer frame‑side lock nut for securing BBS01 BBS02 BBSHD BBS03 mid‑drive motor to frame BB shell. NOT gearbox‑internal nut / crank bolt, installation spare replacement part。
This is the outer frame‑side M33 threaded lock ring, used to fasten Bafang BBS‑series mid‑drive motor firmly onto bicycle frame bottom‑bracket shell. It is essential hardware for ebike conversion installation.
✅ Bafang BBS01 / BBS01B（G340 M215）
✅ Bafang BBS02 / BBS02B（G340 M315）
✅ Bafang BBSHD / BBS03（G320 M615）
✅ Bafang G341（M225 M325）
Universal for full BBS‑series mid‑drive motors. Not compatible with hub‑motors or other‑brand mid‑drive units.
| Parameter | Value |
|---|---|
| Product Name | BBS Bottom‑Bracket Mounting Lock Ring |
| Thread Spec | M33 |
| Material | Carbon Steel |
| Recommended Tightening Torque | 50‑60 Nm |
| Installation Position | Outside bicycle frame bottom‑bracket shell (motor outer side) |
| Remarks | Frame‑mount hardware; NOT gearbox‑internal nut / crank bolt |
1 × Bottom‑Bracket Mounting Lock Ring
✅ Full BBS‑Series Universal Fit: Works for BBS01, BBS02, BBSHD, BBS03, G340, G320, G341 mid‑drive motors.
✅ Secure Frame Mounting: M33 thread lock ring clamps motor against frame bottom‑bracket shell, prevents motor loosening during off‑road & heavy‑load riding.
✅ OEM‑Precision Thread Machining: Matches original thread specification, direct replacement for lost, worn or deformed original lock ring.
✅ Conversion & Overhaul Essential Hardware: Must‑have spare for new ebike conversion, motor reinstallation and repair projects.
✅ High‑Strength Carbon‑Steel Construction: Resists deformation under high mounting torque for long‑term reliability.
Brand: After‑market compatible for Bafang
Product Name: BBS Bottom‑Bracket Mounting Lock Ring
Thread: M33
Material: Carbon Steel
Recommended Torque: 50‑60 Nm
Fitment: Bafang BBS01 BBS02 BBSHD BBS03 G340 G320 G341 mid‑drive motors
Installation Location: Outside frame bottom‑bracket shell
Package Content:1 × Bottom‑Bracket Mounting Lock Ring
❗ Critical distinction: This lock ring mounts outside frame bottom‑bracket shell. Suggest tightening torque: 50‑60 Nm. Appropriate socket tool is required for installation. Double‑confirm required part location before placing order to avoid wrong‑item purchase. Minor measurement tolerance ±1 mm is normal. Only lock ring included; motor, frame, tooling shown in demo pictures are NOT included. Ideal spare stock for ebike conversion shops, DIY builders and wholesale distributors.
We specialize in mid-drive motors and e-bike parts. Strict testing, powerful R&D and flexible OEM service guarantee long-term cooperation.
It used to take me weeks to hunt down hard‑to‑find e‑bike spare parts. Their compatibility‑check technical support saved me countless repair headaches. Reliable supplier I can always count on.
For more FAQs and further details, please get in touch with us
We supply genuine OEM parts and premium compatible aftermarket replacement parts for e-bikes, including motor components, controllers, throttles, PAS sensors, wiring harnesses, connectors and Bosch form-factor batteries.
We serve mainstream drive system manufacturers: Ananda, Bafang, Aikema, Tongsheng, Shengyi, Bosch and more. We also provide repair components for complete e-bike brands including Sur‑Ron, Aventon, Trek and many others.
All items are brand-new and inspected before shipment. We do not supply second-hand or refurbished goods.
Our team verifies compatibility according to your bike model, motor info or original part photos. We confirm available OEM parts or recommend workable alternative solutions.
Yes. Flexible order sizes are supported, ranging from single spare parts to bulk purchases.
Sea freight, air freight and rail transport are optional.
Lead time varies by item and shipping mode. We confirm exact timelines before each order and share tracking updates.
We provide part identification, model matching and full order follow-up support.
