BGM Pro crankshaft (rotary valve) advanced stroke 60 mm, connecting rod 128 mm, pin = Ø16 mm - Vespa PX200, Rally200 (Ducati), Cosa200, Motovespa TX200 - suitable for the Quattrini M244/VMC244 cylinder

Description

Special crankshaft with extra-long connecting rod, e.g. for Quattini M244, VMC Explorer 244 This crankshaft has been equipped with an extra-long connecting rod (128mm instead of 110mm). e.g. for Quattrini M244, VMC Explorer 244
It is the perfect crankshaft for special engine conversions where a long connecting rod is required.
Thanks to the significantly better connecting rod ratio (0.23 instead of 0.29), engines with this shaft run particularly smoothly.
STROKE: 60 mm
CONNECTING ROD: 128 mm
ADMISSION: Rotary valve (cheek width same as PX200)
PISTONS: Ø16mm (Ø15mm also possible with piston pin conversion bearing, see accessories)

MATERIAL
The bgm PRO Touring crankshafts are forged. The material is denser and therefore dissipates heat better. In addition to the cranks, the connecting rod is also forged
BEARINGS
The lower connecting rod bearing is lubricated by two large lubrication slots and a total of four additional side pockets. The SSC racing bearing and side thrust washers ensure a solid bearing. The upper connecting rod bearing is lubricated via two lubrication holes. The INA piston pin bearing is included in the crankshaft.
ENTRANCE CORNER
Compared to many other racing shafts, the bgm PRO Touring shaft has a noticeably better intake timing arrangement. With tuning cylinders, the standard shaft, with its very short suction time, cannot keep up. The bgm PRO shaft, however, closes on a PX motor approximately 58° after top dead center (this varies depending on the motor case). The engine can be tuned well with these timing angles. TIP: If the intake is worked so that the crankshaft passes into the intake slot first, additional power can be gained. A good value in this case is around 120° from TDC
The crankshaft design of the PX engines is based on that of the first 125 cc engines from 1960 with a power output of approximately 5 HP. Unfortunately, Piaggio never modified this design in subsequent increases in displacement. The load capacity of the crankshaft of the standard 200 cc models with 12 HP has already been mathematically exhausted. The crank webs are very narrow and have very little overlap (web material available above the lower crank pin in terms of diameter). This means that neither a particularly high interference nor a large crank pin can be used, as would be necessary (for the performance of today's engines).
The BGM PRO Touring crankshaft has a very high quality of materials and bearings. Furthermore, the crank pins are glued to ensure maximum torsional rigidity. Based on the positive experience gained over many thousands of kilometers of testing our engines in everyday use, we approve BGM PRO Touring crankshafts for outputs up to 25 HP. For engines in this power range, we recommend the use of a lightened sprocket with a maximum weight of 2300 grams.

The conclusion is that the bgm PRO crankshaft offers the highest quality from all points of view in every component. The precision in manufacturing, the materials used and, above all, the precise balancing leave nothing to be desired. This ensures extremely smooth and vibration-free engine operation