LOSI Promoto-MX Chain Roller 70 Manganese Steel MX070 by GPM  [MX070]

Promoto-MX chain roller service part

This replacement chain roller is an RC-scale drivetrain spare designed for the LOSI Promoto-MX motorcycle platform. It pairs a manganese steel chain element with a size 70 roller to restore lateral guidance and consistent chain tracking on 1/4 scale Promoto-MX machines. The design prioritises drivetrain reliability and predictable behaviour during regular track sessions or practice.

Fitment covers the Promoto-MX RTR models listed below; installation requires removing the existing roller, seating the new unit in line with the chain path, and securing fasteners to the original mounting points. After fitting, verify chain tension and lateral alignment, and inspect the roller mount and fasteners for wear or deformation before reuse.

As a service item rather than a tuning upgrade, this roller helps maintain even wear across sprockets and keeps the drive feeling stable under throttle changes when chain alignment is preserved.