Primary Case

Back in the day most racers used replacement primary case covers that provided better cornering clearance and lighter weight. The stock Bonneville and Thruxton primary covers are heavy, and incorporate a rather antiquated mechanical clutch actuation system.

In keeping with traditional styles, and functionality, Streetmaster has developed an aluminum primary cover that is almost three pounds lighter than stock and incorporates a hydraulic clutch!

The design consists of two pieces allowing quick clutch adjustments without the necessity of draining the case or removing the entire cover. The clutch cover can also be removed without disconnecting the hydraulic lines eliminating the need to re-bleed the system.

Besides saving weight, the pull of the hydraulic unit is light and can easily accommodate heavier clutch springs.

Thruxton and Bonneville primary cover: $949. Will accept customer provided master cylinder (Magura or Brembo). We’re in the process of establishing kit pricing complete with master cylinder and hose options.