This is a set of optional 1.1mm clutch springs. This is a common clutch spring for RB Concepts WS7 and WS7II engines. The stiffer the spring, the later the clutch will engage allowing the engine to spool up to a higher RPM range before the clutch comes on. The later the clutch engages, the more the clutch will slip causing the clutch shoes to wear out more quickly.
This product was added to our catalog on May 27, 2004