Crankdhaft BGM Evolution - stroke 52mm, conrod 105mm, webs Ø 90mm - Piaggio Maxi 2 tempi, Aprilia SR 125, Gilera Runner 125FX-180FXR

Description

The bgm EVOLUTION crankshafts are racing shafts of the highest quality.

The completely forged shafts are finely balanced full metal shafts. Both the crank webs and the connecting rod are forged. This gives the shaft an unbelievable resistance.

In order to achieve the highest possible weight, enormously important for a low-vibration engine run, the shafts were not provided with plastic paddings. Instead, the crank webs were designed directly as solid web shafts. It may not look as colourful, but it has only advantages.

The solid cheek shaft, by increasing the precompression, results in a better filling level of the cylinder over the entire speed range.

The bearing is in no way inferior to this top quality. Thus the SSC racing bearings resist even the most extreme speed orgies. The double slotted conrod with silver cage, as well as double lubrication holes in the upper conrod bearing, can withstand even the most brutal continuous loads.

The holes, in order to achieve optimal balancing, are balanced with copper and aluminum weights.

Thanks to its very high weight and the choice of balancing weights, it achieves first class running characteristics.

Piaggio has used two different types of crankshaft in its automatic 2-stroke engines in the 125cc-180cc displacement segment. These differ only in the diameter of the crank webs and the pin diameter of the lower connecting rod eye.

The early engines, as used in the SKR, TPH and Hexagon models of the EX series, used crank webs with a diameter of only 90mm.

The later engines of the Gilera Runner FX/FXR, Piaggio Skipper, Hexagon LX/LXT and Italjet Dragster 125/180 series used crank webs with a diameter of 92mm.

So the shafts of the younger engines do not fit into the old cases. For this reason almost all tuning crankshafts are manufactured with 90mm side plates (BGM, Malossi). So they always fit into all housings.