STONE Pulley Wheel 11T 13T 15T 17T CNC POM Bearing Rear Derailleur Jockey Wheel MTB Road Bike 8 9 10 11 12 Speed

Upgrade your bike drivetrain with the STONE Pulley Wheel, specially designed for riders who want smoother shifting, lower drivetrain noise, stronger rigidity, and better durability.

Compared with traditional injection molded pulley wheels, STONE pulley wheels use CNC machined POM engineering plastic combined with precision sealed bearings, offering better dimensional accuracy, quieter operation, and improved long-term durability.

The structure design provides higher stiffness and impact resistance, making it ideal for MTB, road bike, gravel bike, and long-distance riding.

⭐ Main Features

✔ Structure Design

• Higher rigidity

• Better impact resistance

• More stable chain guidance

• Better long-term durability

• Easier cleaning and maintenance

Ideal for aggressive riding and high-mileage use.

✔ High Precision CNC Machining

Each pulley wheel is CNC machined for:

• Better roundness

• Lower friction

• More stable rotation

• Reduced drivetrain vibration

The precise tooth profile helps improve chain engagement and shifting stability.

✔ Premium POM Engineering Plastic

Made from high-strength Polyoxymethylene (POM):

• Low friction coefficient

• High wear resistance

• Excellent dimensional stability

• Quiet operation

• Better durability than ordinary nylon pulleys

POM is widely used in precision mechanical parts and high-performance drivetrain components.

✔ Sealed Bearing System

Built with high-quality sealed bearings for:

• Smooth rotation

• Reduced noise

• Lower rolling resistance

• Longer service life

The bearing (689RS) design is replaceable for easier maintenance and lower future repair cost.

✔ Compatible with Most 8-12 Speed Bikes

Suitable for:

• MTB

• Road Bike

• Gravel Bike

• Folding Bike

• Touring Bike

Compatible for Shimano and for SRAM rear derailleurs.

⚙ Specifications

Brand: STONE ​
Type: Pulley Wheel ​
Material: CNC POM Engineering Plastic ​
Bearing: NSK 689-2RS Sealed Bearing
​Thickness: 8mm
​Inner Hole: 6mm ​
Compatible Spacer Sizes: 4mm / 5mm / 6mm ​

Color:

• Black Pulley + Red Cover

• Black Pulley + Black Cover

📏 Size / Weight / Outer Diameter

🔧 Upgrade Recommendation

Upper Guide Pulley

The upper pulley is close to the cassette, so oversized pulleys may touch the cassette.

Recommended:

• Increase by maximum +1T compared with original size.

Example:

• Original 11T → Max recommended 12T

Lower Tension Pulley

The lower pulley has more clearance.

Recommended:

• Increase by +1T or +2T

Larger pulley wheels can:

• Improve chain rolling smoothness

• Reduce drivetrain friction

• Improve riding feel

⚠ Compatibility Notes

✔ Compatible for most Shimano / SRAM / MTB rear derailleurs

❌ NOT compatible for SRAM AXS Flattop road chains

⚠ for Shimano 12s road chain: ​The original Shimano 12s quick link may be too narrow. ​Replacing it with aftermarket 12s quick links usually solves compatibility issues.

📦 Package Includes

1pc or 2pcs x STONE Pulley Wheel