The STONE BCD120P Round Narrow Wide Chainring is designed for compatible domestic PR5 / PR6 cranksets. Made from premium 7075-T651 aluminum, it features a durable CNC-machined structure, anodized surface treatment, and a narrow-wide tooth profile for stable chain retention and efficient power transfer.
Available in 38T to 54T, this chainring is suitable for road riding, commuting, DIY upgrades, gravel, and mixed-terrain use.
Key Features
- BCD120P chainring for PR5 / PR6 compatible cranksets
- Round narrow-wide tooth design
- CNC machined from 7075-T651 aluminum
- 4mm thickness for lightweight performance
- Anodized finish for corrosion and wear resistance
- Compatible with 9/10/11/12-speed Shimano chains
- Compatible with 9/10/11/12-speed SRAM non-FlatTop chains
- AXS / FlatTop tooth profile available by customization
- Available from 38T to 54T
- Black anodized finish
- Designed for road, commuting, DIY builds, and gravel riding
Tooth Profile Compatibility
Default Tooth Profile: Non-AXS 9-12s chain
For Shimano 12-speed chains, we recommend replacing the original quick link with a KMC 12-speed quick link for improved compatibility.
Compatibility
Crank Compatibility
This chainring is designed for:
- PR5 cranksets
- PR6 cranksets
- Compatible domestic cranksets using the BCD120P standard
Please confirm your crankset interface and bolt pattern before purchase.
Riding Applications
Suitable for:
- Road cycling
- Commuting
- DIY bike upgrades
- Gravel riding
- Mixed-terrain riding
- Fitness riding
Specifications
| Item | Specification |
|---|---|
| Brand | STONE |
| Model | BCD120P |
| Type | Round narrow-wide chainring |
| Material | 7075-T651 aluminum |
| Hardness | Approx. 150HB |
| Thickness | 4mm |
| Process | CNC machined |
| Finish | Anodized |
| Color | Anodized Black |
| Tooth Range | 38T, 40T, 42T, 44T, 46T, 48T, 50T, 52T, 54T |
| Default Tooth Profile | Non-AXS |
| Custom Tooth Profile | AXS / FlatTop / T-Type available（Please contact us if you need AXS tooth profile ） |
| Compatible Cranksets | PR5 / PR6 compatible cranksets |
Size and Weight Chart
| Teeth | Max Outer Diameter | Weight | SKU | Color |
|---|---|---|---|---|
| 38T | 162 mm | 55.4 g | BCD120P-38TY | Anodized Black |
| 40T | 170 mm | 66.9 g | BCD120P-40TY | Anodized Black |
| 42T | 178 mm | 71.4 g | BCD120P-42TY | Anodized Black |
| 44T | 186 mm | 86 g | BCD120P-44TY | Anodized Black |
| 46T | 194 mm | 89.8 g | BCD120P-46TY | Anodized Black |
| 48T | 202 mm | 95.6 g | BCD120P-48TY | Anodized Black |
| 50T | 210 mm | 106.2 g | BCD120P-50TY | Anodized Black |
| 52T | 219 mm | 114.3 g | BCD120P-52TY | Anodized Black |
| 54T | 226 mm | 128.6 g | BCD120P-54TY | Anodized Black |
Weights are for reference only. Product weight may vary slightly due to production updates or structural changes.
Design Details
The STONE BCD120P chainring features a carefully optimized narrow-wide tooth structure for reliable chain engagement.
Tooth Design Advantages
- Narrow-wide tooth profile helps improve chain retention
- Mud clearance grooves help reduce mud buildup
- Rounded entry surfaces guide the chain smoothly onto the teeth
- Reinforced tooth back improves support and stability
- CNC-machined tooth shape improves fit and drivetrain smoothness
- Round chainring design provides consistent pedaling feel
Material and Finish
Each chainring is made from premium 7075-T651 aluminum plate, selected for its strength, hardness, and machining stability.
The T651 material condition includes heat treatment and pre-stretching, helping reduce internal stress and improve dimensional stability after CNC machining. This helps minimize deformation and improves chainring flatness after installation.
The anodized surface treatment helps prevent long-term oxidation and improves wear resistance.
Important Notes
- Default tooth profile is Non-AXS.
- For SRAM FlatTop / AXS / T-Type chains, please choose or request the custom AXS tooth profile.
- For Shimano 12-speed chains, replacing the original quick link with a KMC 12-speed quick link is recommended.
- Different tooth counts may have slightly different appearance and cutout design.
- Please confirm crankset compatibility before purchase.
- Product color and finish may vary slightly due to lighting, screen display, and production batch differences.
