
This part being universal, it may require adaptations
EK CHAIN 420SR 420 (ref. 420SR-STL 100 SPJ) — a transmission designed for riders seeking reliability and ease of maintenance. From the SR series, this chain maintains its flexibility even after long use thanks to a specialized heat treatment applied to the plates, which enhances their durability and wear resistance.
Versatile, it caters to urban, quad, motocross, and roadster environments — ideal for small displacement or trail/road learning. Compact and lightweight, the 420SR is particularly suited for 50 cc motorcycles listed in compatibility, while remaining appropriate for any setup accepting the 420 pitch. Its raw steel finish facilitates visual wear inspection and maintenance (regular cleaning and lubrication recommended).
To preserve its longevity: check the tension, monitor the wear of the sprocket/crown teeth, and lubricate according to usage frequency. Manufacturer reference: 420SR-STL 100 SPJ.