The STONE 3-Bolt Direct Mount Oval Chainring is designed for SRAM-style 3-bolt direct mount cranksets with 3mm offset, suitable for Boost 148mm MTB frames.
Made from aerospace-grade 7075-T651 aluminum, this chainring offers high stiffness, excellent durability, and reliable chain retention for mountain biking, racing, and high-load riding.
Available in Hollow and Aero styles, with tooth sizes from 26T to 40T.
Specifications
| Item | Details |
|---|---|
| Brand | STONE |
| Product Type | Oval Chainring |
| Crank Interface | 3-Bolt Direct Mount |
| Offset | 3mm |
| Frame Compatibility | Boost 148mm |
| Material | Aerospace-grade Aluminum 7075-T651 |
| Color | Anodized Black / Silver |
| Speed Compatibility | Standard 9 / 10 / 11 / 12 Speed (Not for AXS flattop chain) |
| Tooth Options | 26T / 28T / 30T / 32T / 34T / 36T / 38T / 40T |
| Thickness | 6.7mm |
| Hardness | HB150 |
| CNC Precision | 0.03mm |
| Style Options | Hollow / Aero |
Important Compatibility Notice
Please check carefully before ordering.
- Compatible with standard 9 / 10 / 11 / 12-speed chains
- Compatible with SRAM 3-bolt direct mount cranksets
- Suitable for Boost 148mm frames
- Not compatible with SRAM AXS FlatTop chains
- Not compatible with SRAM T-Type chains
- Not compatible with 8-bolt crank interface
- If using a Shimano original 12-speed road bike chain, please replace the original Shimano 12-speed quick link with another brand quick link, because the original quick link is too narrow.
Fitment
Compatible with SRAM Boost 148 cranksets, including:
- For SRAM GX
- For SRAM NX
- For SRAM XX1 / XX1 Eagle
- For SRAM X01 / X01 Eagle
- For SRAM X0
- For SRAM X9
- For SRAM X7
- For SRAM S2210
- For SRAM S1400
Also suitable for other cranksets using the same SRAM 3-bolt direct mount interface.
Size & Weight Chart
| Teeth | Max Outer Diameter | Hollow Weight | Aero Weight |
|---|---|---|---|
| 26T | 121.5mm | 47g | 49.3g |
| 28T | 129.5mm | 52.9g | 55.5g |
| 30T | 137.5mm | 57.3g | 62g |
| 32T | 146mm | 63.6g | 68.4g |
| 34T | 154mm | 67.5g | 75.7g |
| 36T | 162mm | 71.6g | 82.4g |
| 38T | 169mm | 79.9g | 91.3g |
| 40T | 178mm | 84.4g | 97.1g |
Note: Due to manual measurement, slight weight variation may occur.
Hollow Style vs Aero Style
| Style | Features |
|---|---|
| Hollow Style | Lighter weight, lower chain noise, suitable for most riders |
| Aero Style | Strong visual design, slightly heavier, chain noise may be louder than hollow style |
Key Features
- Oval chainring design for smoother pedaling and improved power transfer
- Narrow-wide tooth profile for better chain retention
- Helps reduce chain drop during rough riding
- Improved self-cleaning performance in mud, soil, and dirty conditions
- CNC-machined from high-strength 7075-T651 aluminum
- Lightweight structure with excellent stiffness
- Suitable for MTB, trail riding, XC, and racing use
Advantages
1. Aerospace-Grade Material
Made from high-strength 7075-T651 aluminum, offering excellent stiffness, durability, and long service life.
2. High-Precision CNC Machining
Manufactured with 0.03mm machining accuracy for smooth chain engagement and stable riding performance.
3. Race-Ready Tooth Profile
STONE’s narrow-wide tooth design improves chain grip, reduces chain drop, and delivers reliable performance under high-load riding conditions.
4. Lightweight & Durable
Available in Hollow and Aero versions to meet different rider preferences for weight, appearance, and riding feel.
Package Includes
- 1 × STONE Oval Chainring
- 3 × Steel Mounting Bolts
STONE Chainrings — Race-Ready Precision
Trusted by riders worldwide and used by race teams in Europe and the USA, STONE chainrings are built for high-load riding and competitive performance.
Using aerospace-grade 7075-T651 aluminum, STONE chainrings deliver outstanding stiffness, strength, and durability, with a tested lifespan of up to 15,000 km.
High-precision CNC machining within 0.03mm tolerance ensures efficient power transfer, stable chain engagement, and reliable performance under pressure.
STONE is more than a manufacturer — we focus on tooth profile innovation, lightweight design, secure chain retention, and race-proven reliability.
Engineered for racing. Proven on the trail.
