
The RFX Race front sprocket 12 teeth (manufacturer reference: FXFS 40-12 55ST) is designed for motocross riders looking for a reliable and straightforward drive component. CNC machined from alloy steel, this sprocket is carburized to achieve approximately 60 Rockwell (HRC), a treatment that strengthens the surface and limits wear during off-road use. Its silver finish and standard version make it a clean-looking part that is easy to integrate.
RFX also offers sprockets with lightening holes on certain models to reduce rotating mass; however, this standard model is designed for durability and consistent performance. Compatible with 520 chain drives, it is commonly fitted on trails and motocross bikes such as the SUZUKI RM-Z 250 (2012), DR-Z 400 E (2004), or RMX 250 (1999) depending on the applications. Always check the inner diameter and axle of your motorcycle before installation.