Crankshafts for scooters
at SIP Scootershop
The Crankshaft is also one of the most stressed engine components in a scooter. It rotates many thousands of times per minute and the performance of an Engine depends on its quality. The basic requirements for optimum engine tuning in scooters are minimal manufacturing tolerances, high speed stability, low bearing play and maximum durability of the shaft. Crankshafts in scooter engines that have already clocked up many kilometres or have more power often have worn Bearing and shaft seal seats and even worn connecting rod bearings. In such cases, the Crankshaft should be replaced during a major engine overhaul.
In the field under "Scooter", you can now select your "Vehicle type" to see all the Crankshafts that are suitable for it. If this is not quite clear, you can alternatively restrict the make of the scooter in the vehicle selection with "Select manufacturer".
MINARELLI or PIAGGIO are the names of the players here, and most of them are two-strokes
There are countless 50 cc scooters. But most of them use one of the engines listed here. Even if a scooter is not listed here, you can find a wide range of parts if you know which Engine is installed.
50-80 cc 2T AC/LC: This is where the music is played. Large performance increases are possible with two-stroke engines. Of course, we also stock standard Crankshaft. The most important engine types here are
PIAGGIOmany 50 cc scooters from APRILIA, DERBI, GILERA, ITALJET and PIAGGIO are equipped with the same PIAGGIO two-stroke engine. The Modern Vespas ET2/LX/Primavera/S/Sprint also run this engine in the AC version. The Crankshafts of the air-cooled and water-cooled Models are the same.
MINARELLI horizontal: manufacturers such as APRILIA, MALAGUTI, MBK and even YAMAHA are happy to use this 50 cc two-stroke engine with a horizontal Cylinder. The Crankshafts of the air-cooled and water-cooled Models are the same. A distinction is made between Ø10 mm and Ø12 mm Gudgeon Pins.
MINARELLI vertical:The two-stroke engine with vertical Cylinder can be found on many APRILIA, ITALJET, MBK and YAMAHA Models. A distinction is made here between Crankshafts with Ø10 mm and Ø12 mm Gudgeon Pins.
MORINI: Found on many ITALJET, MALAGUTI and SUZUKI scooters.
PEUGEOT: Unlike other manufacturers, Peugeot only uses its own engines for its scooters. A distinction is made here between horizontal and vertical Cylinders and in some cases the Euro standards (Euro1 / Euro2 etc.). We recommend paying attention to the model designation when making your choice.
50 ccm 4T AC/LC: The 50 cc four-stroke engines fulfil the strict exhaust emission standards, but are usually weaker than their two-stroke cousins. Our range currently includes standard Crankshafts for air-cooled (AC) PIAGGIO and GY6 Engines.
The different crankshaft types for 50-90cc scooters
We divide the crankshafts for scooters into the following groups.
Standard Crankshaft
Standard crankshafts are usually faithful reproductions of the originals. However, various improvements have been made to some models, e.g. a Gudgeon Pin Bearing for reduced frictional torque instead of a bronze bush or a polished forged connecting rod. The transition to Racing Crankshafts is sometimes fluid.
Racing crankshafts
Racing Crankshafts are basically crankshafts that deviate from the standard specifications:
- different shape of the crank webs
- more stroke
- longer or higher quality Conrod
- Variator/pole wheel stub not intended for the original parts
Our top brands for Crankshafts for scooters
MALOSSI: Finest Racing Crankshaft with a decent price-performance ratio.
MALOSSI MHR: If you want to take it to the extreme, there's no getting round the MALOSSI MHR.
RMS: Standard shafts that are perfectly suited as inexpensive original replacements.
POLINI: Perfect for street tuning and Engines with a little more power.
OTTOPUNTOUNO: High-end level and absolutely suitable for racing.
Technology tips
If you want to delve even deeper into Crankshaft technology, we recommend our Technology blogs.
Customers ask - SIP answers
"Do I absolutely need new bearings and Oil Seals for the new Crankshaft?"
The bearings are the connection between the Engine and the Crankshaft and are constantly exposed to the highest loads. The Oil Seals seal the crankshaft stump on the right and left. If both components are worn, the Engine will run unevenly or not at all. We recommend installing new bearings and Oil Seals when replacing the Crankshaft to avoid unpleasant surprises.
