Crankshafts
for Maxiscooter 2T
The Crankshaft is also one of the most heavily stressed engine components on a two-stroke maxi scooter. It rotates thousands of times per minute and the performance of an Engine depends heavily on the quality of the Crankshaft. Very low manufacturing tolerances, enormous speed stability, hardly any bearing play and durability of the Shaft are the basic requirements for successful engine tuning. Crankshafts in maxi-scooter engines that have already clocked up a few kilometres or have more power can sometimes have worn Bearing and shaft seal seats or worn connecting rod bearings. In such cases, the Crankshaft, among other things, should be replaced during an engine overhaul.
In the field under "Maxiscooter 2T" you can now select your "Vehicle type" to see all suitable Crankshafts. If this is not entirely clear, you can alternatively restrict the make of the scooter in the vehicle selection with "Select manufacturer".
The wide world of maxi scooters
The market for maxi scooters is almost inexhaustible. However, if you limit the world exclusively to two-stroke engines, you quickly realise that, apart from some HONDA, PEUGEOT and various other engines, PIAGGIO two-strokes are actually the only true engines in this segment.
100-180 cc 2T AC/LCalmost an old-timer. The popular GILERA/PIAGGIO 125-180 cc two-stroke engine is the top dog here. Easy to tune and then very powerful. The Crankshaft is the key to power here. The PIAGGIO 125-180 cc 2T AC/LC is probably the most common engine type for maxi scooters. Models such as the PIAGGIO Hexagon/SKR, GILERA Runner FX/FXR or APRILIA SR, which are now considered classics, are fitted with PIAGGIO engines in versions with air-cooled or water-cooled cylinders. However, it does not matter whether the Crankshaft is AC or LC, it fits both engine types.
The different crankshaft types for maxi scooters 100-180 ccm 2T
We divide the Crankshafts for classic maxi scooters into the following groups.
Standard Crankshaft
Standard Crankshafts are replicas of the originals. However, improvements have been made to some models, e.g. a Gudgeon Pin Bearing for a lower frictional torque instead of a bronze bush or a polished forged connecting rod. The transition to Racing Crankshafts is usually seamless.
Racing crankshafts
In principle, racing crankshafts are all crankshafts that deviate from the pure standard specifications:
- different crank web shape
- more stroke
- longer or higher quality Conrod
- Variator/pole wheel stub - not intended for the original parts
Long Stroke Crankshafts
In principle with similar specifications to the Racing Crankshafts, but with more stroke. Cylinder Head and/or cylinder base spacers are required here to compensate for the longer stroke.
More stroke = more cc = more power
Standard stroke: In addition to the cylinder diameters, the original engine types also differ in terms of stroke, as we have described in the engine classes.
Long stroke: If you want more torque, you can opt for long-stroke variants. We refer to Racing Crankshafts with a longer stroke as Long Stroke Crankshafts to make them easier to distinguish. These are currently only available for PIAGGIO 125-180 ccm two-stroke engines with55 mm stroke .
Our top brands for Crankshafts for maxi scooters
The most popular crankshaft manufacturers for maxi scooters are
MAZZUCCHELLIstandard shafts that are perfectly suited as inexpensive original replacements.
MALOSSI: Finest Racing Crankshafts with a decent price/performance ratio.
JASIL: Inexpensive shafts with good quality.
PM TUNING: High end shafts for extreme inserts.
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.
