Made from 3mm thick High Carbon British Spring steel and coiled as tight as possible on some custom spring tooling to get maximum strength! 

These springs are designed to work with FS Steel Shoes, but also really successful when used with the heavier UFC shoes for a little less rpm. Not suited to stock clutches, the wire is too thick.
 
Coated with a think heat resistant paint to prevent fade over time Provides 10,000+rpm on FS Steel Clutch Shoes.
 
NOT suited to big bore engines (too high engagement rpm - will cause excess slip on taller gears and not required for big engines anyway)