Mugen MRX5 20T 7075 Hard Pulley Upgrade by Arrowmax AM-MRX5-H0251B  [AM-MRX5-H0251B]

MRX5 aluminium pulley for precision tuning

The Arrowmax AM-MRX5-H0251B serves as an RC-scale replacement for the Mugen MRX5 belt-drive layout. Manufactured by CNC from 7075 T6 aluminium with a hard surface treatment, it provides a resilient, lightweight rotating component while keeping existing shaft positions unchanged.

Design notes: side openings let contaminants escape the belt contact zone to reduce material buildup on the friction surface. The hard coating increases wear resistance and the high-strength 7075 alloy keeps mass low, supporting faster spool-up in belt-driven tuning setups. Installation follows the MRX5 chassis' stock pulley retention, so no additional adapter is required.

Use case: install this pulley to reduce rotating inertia versus heavier parts, maintain reliable belt engagement under normal circuit conditions, and simplify cleaning thanks to the vented holes.