The bgm PRO Touring crankshafts are forged. The material is denser and therefore conducts heat better and is more resistant to distortion. In addition to the crank webs, the connecting rod is also forged.
The shaft is available with 60mm (long stroke) and with 57mm (standard) stroke. With the long-stroke variant, more displacement is achieved, and at the same time the cylinder`s intake angles (overflow and exhaust ports) can be changed to increase performance.
The crankshaft design of the PX engines is based on that of the first 125cm³ engines from 1960 with approx. 5 HP power. Unfortunately Piaggio never really changed this design in the later displacement extensions . Thus, the load capacity of the crankshaft with the standard 200cc models with 12HP is mathematically already exhausted. The crank webs are very narrow and have very little overlap (web material that, seen in diameter, is available above the lower crankpin). This means that neither a particularly high interference fit nor a large crankpin can be used, as would be necessary (for the performance of today`s engines).
The BGM PRO Touring crankshafts have a very high material quality and bearing. In addition, the crankpins are glued for maximum torsion resistance. Due to the positive experiences, collected in many thousands of test kilometers of our own daily used engines, we release the BGM PRO Touring crankshafts for engine power up to 25HP. We recommend for engines in this power range the use of a lightened pole wheel with max. 2300gr.