
This part being universal, it may require adaptations
EK CHAIN 420SR 420 (Manufacturer reference: 420SR-STL 126 SPJ) is a transmission chain designed for lightweight and off-road machines where compactness and reliability are paramount. Coming from the SR series, it features a specialized heat treatment on the plates aimed at enhancing wear resistance while maintaining the chain's flexibility after miles of use.
Designed for urban, quad, motocross, and roadster environments, this chain is aimed at riders looking for a robust transmission part for small displacement sprockets and crowns. Its construction limits premature stiffening of the links while facilitating tension adjustment and regular maintenance (lubrication and link spacing checks).
Common compatibilities: RIEJU MRT 50 SM (2025), FANTIC XM 50 PERFORMANCE (2025), BETA RR 50 MOTARD (2025). For safe installation, follow the manufacturer's procedures for tension and fastening. EK CHAIN offers a simple and reliable solution to restore the transmission of your 50 cc or lightweight machine.