







EK/PBR 420SR Chain Kit 11/52 - Standard Sprocket
This final drive kit includes the EK 420SR chain (non O-ring), a PBR steel front sprocket, and a standard steel rear sprocket — the ideal combination for urban use and light off-road applications. Designed for small displacement machines, it focuses on simplicity, robustness, and reliable transmission without frills.
Check compatibility with your model before installation. Ideal for small displacement bikes like RIEJU MRX 50, SMX 50, and MRX 50 PRO. After installation, check and adjust the tension, and regularly maintain the chain to preserve the longevity of the final drive.