GPM Racing Medium Carbon Steel Hub Chain Sprocket Set (35T/11T) for Losi Promoto-MX Motorcycle RTR FXR (MX3511S)

Precision-fit medium carbon sprockets

The MX3511S sprocket set is supplied as a scale replacement for LOSI Promoto-MX 1/4 motorcycle RTR models. The rear hub and front sprockets use medium carbon steel to improve wear resistance over standard stamped components while retaining a direct fit to factory drivetrain parts.

Configured for direct replacement, this kit emphasises dependable drivetrain behaviour and part life rather than changing final ratios. The screw pin included matches factory fastening method to simplify installation on compatible units.

Installation notes: remove the stock hub sprocket and front pinion, transfer spacers or washers as required, fit the 35T rear hub sprocket and 11T front sprocket, and secure the screw pin to recommended torque. Verify chain alignment and perform a controlled run-in before full-power operation.

Packing includes

• Hub Chain Sprocket 35T – 1pcs
• Front Chain Sprocket 11T – 1pcs
• Screw Pin M4x2.5×14 – 1pcs

Original Name / Part No:

LOS262003+LOS262004

Compatible Models

• LOSI-1/4 PROMOTO-MX MOTORCYCLE RTR, FXR-LOS06000
• LOSI-1/4 PROMOTO-MX MOTORCYCLE RTR, FXR-LOS06002

Use this set to replace worn sprockets and to reduce replacement frequency during regular riding; maintain correct chain tension and alignment to maximise service life.

Is this a direct OEM-style replacement?

Yes, the MX3511S is produced to match the mounting interface of the listed Promoto-MX RTRs for direct replacement.

What advantages does medium carbon steel provide?

Medium carbon steel increases wear resistance compared with standard stamped sprockets, which helps extend service intervals under normal usage.

Will I need to alter chain length or gearing?

No alterations are required since the kit retains the original 35T rear and 11T front tooth counts; fitting focuses on correct alignment and torque.

Recommended installation checks?

Transfer any spacers or washers, secure the screw pin to specification, confirm chain line and bearing clearance, and perform a short moderate-speed run-in.

What should I inspect during maintenance?

Inspect tooth profiles for hooked wear, check the chain for elongation, and monitor bearing smoothness to determine replacement intervals. Write Product Review Please sign in your account before you can write any review. Sign In Close

Made to order: GPM Racing parts are shipped to us from GPM’s factory, so please allow around 14 days for dispatch.