Crankshaft MALOSSI connecting rod 97, stroke 51, cone 20, full circle - Vespa 125 primavera/et3, PK125, PK125XL, ETS

STRENGTH AND RESISTANCE

MALOSSI DRIVE SHAFTS FOR VESPA

The drive shaft of a Vespa is one of the most delicate yet important components of this type of propulsion unit, having to handle the movement of rods and pistons, as well as regulating intake through the crank timings.

The Malossi technical office has dedicated its attention to both of these elements, creating two versions of the drive shaft and developing unique solutions with a high technological value, starting with the choice of materials; top quality as always.

All Malossi drive shafts for Vespa are made from aeronautical quality reinforced steel and are founded in a vacuum. It is a material highly resistant to scratches and guaranteed by the certifications required in Malossi's strict handbook. The "viper head" piston rod's shape is designed to limit weight to a minimum whilst guaranteeing the required rigidity.

Not even the smallest detail has been overlooked. Indeed, Malossi technicians have even worked on the thread on the transmission side axis of the drive shaft, succeeding in significantly increasing resistance by producing smoother stepping. Even the position of the key has been reviewed both in terms of size and shape, so as to no longer damage the thread and contribute to resistance in what is an avant-garde solution. Drive shafts are supplied with special nuts, much stronger, to take advantage of the increased resistance offered by the tighter thread.



SUMP AXLE WITH ROTATING VALVE

In the version for rotating valve propulsion units, the suction phase has been worked into the half crank, inside the circular mass structure itself, which results in a significant inward pitch, whilst maintaining a normal shape externally. This innovative choice has allowed for a unique shape able to guarantee extremely efficient fluid dynamics.

The prominent pitch has always been one of the most delicate elements of Vespa drive shafts when trying to balance the motor correctly. Malossi has resolved this problem by inserting parts made from tungsten into the drive shaft, used as counterweights for increased stability of the shaft itself.



FULL CRANKSHAFT

TheMalossi full crankshaft, designed only for Vespa motors modified for use with a reed valve inlet systems in place of the original rotating valve, is the next level for Vespa enthusiasts.

As with the rotating valve version, this version is also guaranteed to offer optimal balance, having tungsten inserts. Furthermore the half crank on the transmission end has a specially-designed chamfer to ease fresh gas intake under the sump.

The circular mass structure is the zone which benefits the most from this new shaft and sump configuration, receiving the maximum possible pressure level.



DIFFERENT VERSIONS

Drive shafts are available with different piston rod lengths for "small frame" Vespas, on to which the full crankshaft is fitted.

The shaft for motors with a rotating valve inlet has a standard length shaft and piston rod.

Product reserved exclusively for competitive use in areas designated for competitions, according to regulations stipulated by the relevant sporting authority. We do not accept any liability for improper use.