Hybrid crankshaft suitable for the old Vespa models with large chassis, up to 150cc and small cone on the alternator side of the crankshaft. The best known of these models is certainly the Sprint (not Veloce!) as well as the GT and VBB models. Mazzucchelli standard rotary valve crank - VESPA 125-150 with PX taper. With its 57mm stroke this will fit straight in any GT125, GTR125, 150 Super, 150 Sprint, VBA, VBB motor, and add the fatter PX crank taper, so a PX type ignition and flywheel must be used with this cranks , Con rod 105mm, inlet timing 112 degree/-6 degree post TDC.

This crankshaft is a fusion of two types of crankshaft.
So the whole construction up to the generator side cone corresponds to the old specification for the Sprint engines. The cone for the mounting of the flywheel on the alternator side was manufactured with the dimensions of the later PX models.

This not only brings stability advantages as the stub can now be made much thicker, the biggest advantage is the possibility to use a contactless PX ignition. These are still available as original as well as in performance enhanced version from BGM & SIP.

Therefore one can increase the light output and the reliability with this shaft type without large expenditure, under retention of the original engine, around a multiple.

This shaft is manufactured in small series by the Italian steeped in tradition crankshaft manufacturer Mazzucchelli.