A high end crankshaft for all vintage Vespa models. Highest quality, enabling an ideal restoration including a reliable, smooth-running motor.

Together with the cylinder, the crankshaft represents the beating heart of any internal combustion engine. It is amongst the hardest working components and the conversion of the pistons stroke to a rotary movement places the highest demands on both quality and the care taken during construction. The crankshaft should also be well balanced to reduce any unwanted vibrations and the oscillating mass kept to a minimum to support an efficient delivery of the power created by the motor. The big-end bearing rotates at the same rate as the motors RPM, receives lubrication from the petrol/two-stroke oil gas mixture and must withstand two abrupt changes in direction of the piston for each motor revolution. The crank-pin, connecting both crankshaft webs with the con rod, has to be pressed into the webs with a certain clearance to the openings in the webs. If this connection is not strong enough the crankshaft can twist and the crankshaft webs become misaligned and seize. To ensure the big end bearing receives sufficient lubrication the big end of the con rod should be provided with slots to facilitate this.

The SIP Crankshafts:

• Especially fine balancing
• High quality construction materials
• High precision manufacture

This all-new range of crankshafts are produced for SIP in Italy and satisfy all of the above listed demands. We have concentrated our efforts to provide the highest quality combined with tried and tested technological features. Each crankshaft is balanced specifically to suit the stroke, con rod length and model of scooter for which it is intended.

The SIP Premium range of crankshafts includes versions suitable for many of the rarer vintage Vespa models. We placed priority on being in a position to offer high quality aftermarket components to replace the originals which are long out of production.