This is a set of three B10 tempered steel clutch springs for the Ultimate Racing Compak clutch system. These are optional springs that you can use to fine tune the way the clutch engages.
You can choose from six different clutch springs to tune the clutch engagement to your driving style and for different track conditions. Larger diameter springs are stiffer and the clutch will engage higher in the RPM range. Smaller diameter springs are softer and will engage earlier in the RPM range.
Available in six different thicknesses for different track conditions.
B8.5 - 0.85mm springs for very slippery tracks
B9 - 0.9mm for slippery track
B9.5 - 0.95mm for grippy tracks
B10 - 1.0mm for very grippy tracks
B11 - 1.1mm for very high traction or muddy conditions
B12 - 1.2mm for Rally Game class