Primary transmission ratios 25 / 62 teeth (2.48) BGM PRO for Vespa PX

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

The smaller the result, the longer the reduction ratio of the engine, the higher the final maximum 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 Engines requiring such a long reduction is transmitted directly into the gearbox via straight teeth without exerting lateral forces on the auxiliary shaft bearing. Thanks to precise manufacturing, straight tooth drives are still as quiet as helical tooth drives.

PRIMARY KIT
The primary kit included in the delivery contains all the parts necessary for assembly.
The kit also features reinforced BGM Proirmary springs. This protects the entire drivetrain, as the springs do not lock even with high torques and no load peaks are transmitted.
The cover plates in the set have a smaller diameter and only fit BGM Pro primary wheels with 62/63 teeth.

There
The scope of delivery includes the clutch pinion with the corresponding primary gear (both straight-toothed) and a special repair kit for riveting the primary gear onto an existing auxiliary shaft (fir tree).

NOTE: BGM straight tooth primary sprockets and primary gears cannot be combined with Polini or Malossi parts. The module is chosen differently for RGB components for maximum stability.

(USA)