Crankshaft -BGM PRO Racing (rotary valve)- Vespa V50, PK50 S (Ø=19mm cone) 51699 fitting for Vespa V 50 V5SA1T 1974, 2,5 PS, 1,8 kw

The BGM crankshafts are forged like in the good old Piaggio times. In forging, the material is pressed together under temperature and high pressure. This results in a higher density of the material. Heat is dissipated much better. The material is more resistant to distortion. This is a huge advantage compared to crankshafts made to order by other manufacturers whose materials used often do not even reach the level of a series shaft.

Tuning:
The high quality of the material used also allows the use of very light-weight spark plugs without the risk of crankshaft damage. This allows a better acceleration behaviour to be combined with a considerably increased durability of the engine. This is particularly important on engines with large displacement and high speeds.

Control angle:
The control angle of this crankshaft is longer than that of a standard shaft.
Ideal for all cylinders, from 50cc Sport to 112cc Racing, to miss a lot more steam.
On tuning cylinders the standard shaft with its much too short intake time does not keep up. When a certain speed level is reached, it is then really locked off.
The engine can be tuned with the optimized control angles of our shaft as if an original Piaggio shaft was used. Nevertheless, the extended intake angle ensures that even completely made engines can turn out fully.

In addition, the rotary vane inlet of the housing can be extended to create enough space for larger carburettors and to further increase the engine`s performance.

Design:
Crankshaft with so-called small cone with 19mm. Such shafts can be recognized by the diameter of the shaft sealing ring surface on the alternator side. This is the surface which is located after the cone but before the bearing seat of the Limal bearing on the crankshaft stub.

• cone: 19mm,pointed
• control angle: standard
• stroke: 43mm
• common bearing top: 12mm

TIP: The shafts with a diameter of 19mm have a narrow pointed cone which can also break off in strong motors with high speeds. Here the conversion to a crankshaft with 20mm cone is recommended. However, here the conversion of the ignition is necessary.

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