More stroke allows more cubic capacity, which in turn, means more power. That's why most 200er motors, whether race or road tuned, turn to long stroke crankshafts. To balance out stroke increase, spacers are set in either at the cylinder base or head. It's also a simple way to play around with timing.
With long stroke crankshafts, the stroke pivot is further from the crankcase axel: with 60 mm shafts, 1.5 mm. The additional 1.5 mm pushes over the top and lower dead center. To keep the piston from touching the cylinder head, cylinder head/base spacers can be installed or suitable SIP/MMW cylinder heads can be used. Timing changes in any case. Depending on type of race cylinder, there are several favored combinations which we've put together for you in the technical department.
For the MALOSSI 210cc, the following applies:
1.5 mm base compensation: wide rpm range and high PS, lowered torque coupled with late and sudden acceleration.
1.5 mm head compensation: hefty torque and free wheelies in lower rpm's, lower top speeds. This is SIP's favorite touring combination, especially when coupled with a longer transmission.
The MAZZUCCHELLI long stroke crankshafts have a substantially extended intake timing, just like the racing crankshafts. The conrod is partially a polished special edged conrod, and the lower conrod bearing is a silver bearing. It is also available as a strengthened 'K2D' version. The higher solidity of the K2D alloy means it is possible to achieve a higher pressing dimension on the crank pins. This means that the torsion resistance is also increased without welding. This material is now used on all MAZZUCHELLI full circle crankshafts.
Conclusion: A perfect basis for powerful torque touring motors or rpm hefty PS monsters. For those wanting more, we suggest long stroke flowed shafts.
Long stroke crankshaft / stroke 60 mm / connecting rod 105-110 / 24/25 mm, M12
Long stroke crankshaft, with ø 95 mm (flywheel side), ø 97.9 mm crankweb (disc valve side), partially balanced at 12 o'clock, lower connecting rod bearing = silver bearing, 105 mm connecting rod (125/150 cc) or 110 mm connecting rod (200 cc), 60 mm stroke, oil seal housing 24 mm, bearing housing 25 mm, stump cone with M12 thread, incl. connecting rod bearing.
SIP-TIP: SIP/MMW long stroke head, MALOSSI 210cc and SIP Road exhaust for touring set up, 1.5 mm base gasket, SIP Performance/RZ/DSE exhaust, MALOSSI or POLINI, 28-30 mm carburetor as basics for sport set up. Try out a variety of base/head gaskets to find the right one for your needs.