High-end Bell-Shaped Crankshafts (mushroom crankshafts) in LPC design - SERIE PRO crankshafts for Vespa tuning beyond the 25 hp mark.

For powerful Engines, there is always a step up: The SERIE PRO series includes several German-Austrian tuners who offer high-end Crankshafts for performance-oriented Vespa setups with high manufacturing quality, many years of experience and, in some cases, an international reputation. These bell or mushroom crankshafts are inserted when 25 hp and more are realistically on the agenda.

• LPC design (Low Primary Compression) for significantly improved filling level in Reed Valve setups.
• Based on MAZZUCCHELLI or TAMENI with high-quality material and low tendency to twist.
• Smooth engine running thanks to symmetrical cheeks and optimized balance factor.
• Designed for powerful setups with 60-62 mm stroke and Racing Cylinders such as MALOSSI 210.

The Bell-Shaped Crankshaft in LPC design is a diaphragm shaft with 60 mm stroke based on a MAZZUCCHELLI Full Circle Crankshaft. Targeted material removal reduces pre-compression, while at the same time creating more volume for the fresh gas in the crankcase. In conjunction with a "high-suction" Exhaust, the additional mixture stored under the Piston is flushed up very efficiently. The symmetrical mushroom design allows the mixture to flow in unhindered and reduces the tendency to twist, as both cheeks are equally heavy - the Shaft swings cleanly at 12 Clock and runs correspondingly smoothly.

MAZZUCCHELLI now manufactures the Bell-Shaped Crankshaft directly in the factory. In combination with the MALOSSI 210 Piston, this results in a balance factor of around 50 %, with axial play of approx. 2/100. The major advantage of factory production: no subsequent machining work and therefore a significantly lower end price compared to rebuilt standard shafts.

The Bell-Shaped Crankshafts from Scooter & Service follow the same basic principle, but rely on their own bell geometry and extremely high machining quality. They also provide a noticeable power boost and smoother engine running; the 62 mm versions are equipped with DRT eccentric journals.

The Bell-Shaped Crankshaft from worb5 also uses the DRT eccentric journal for an incredible 62 mm stroke. Here, the crankcase must be spindled out a little so that the Conrod, which runs further out, does not hit it, and the Cylinder should be raised by about 1 mm so that the Piston Rings do not move out of the running pattern. The basis is a TAMENI Long Stroke Crankshaft, which has been modified accordingly for this application.

Conclusion: The arms race in the street racer scene is impressively reflected in these Bell-Shaped Crankshafts - a must for PS junkies who want to get the maximum out of their largeframe engines.