PRIMARY-KIT BGM PRO EXTRA LANG
Engines with a lot of torque and early power peak choose the straight-toothed clutches which also require a straight-toothed primary gear (also available as a set with clutch). This allows very long gear reductions to be achieved. Also perfectly suited if the overall gear ratio is too short for very sporty engines with a modified auxiliary shaft and shorter gear steps (e.g. MHR). Another option if the actual gearbox is very short (PX80) or the ratio is too low due to a small wheel diameter (PX200 engine with 8 inch tyres in Oldie).

The smaller the result the longer the motor is stepped down the higher the max. speed can be. The extra-long primary reduction ratios based on the 62/63 tooth primary gear are only available with straight teeth and therefore cannot be combined with conventional (helical) drives.
The high torque of motors requiring such long reduction ratios is transmitted directly into the gearbox via straight teeth without exerting lateral forces on the auxiliary shaft bearing. Due to the precise manufacturing, the straight-toothed drives are nevertheless just as quiet as the helical-toothed drives.

PRIMARY KIT
The primary kit included in the scope of delivery contains all parts required for mounting.
The kit also has reinforced BGM Proirmary springs. This protects the entire drive train as the springs do not go on block even at high torque and no load peaks are transmitted.
The cover plates of the set have a smaller diameter and only fit the BGM Pro primary wheels with 62/63 teeth.

COMPLETE OF DELIVERY
The delivery includes the clutch pinion with matching primary gear (both straight-toothed) and a special repair kit to rivet the primary gear with an existing auxiliary shaft (fir tree).

BITTE NOTE: The straight-toothed BGM primary pinion and primary gears cannot be combined with Polini or Malossi parts. The module is chosen differently for the BGM parts for maximum stability.

(US)