There will be 3 models for the standard crankcase and 1 model for the A-kit crankcase. The difference of the models of the crankshafts is the inertia and weight. With these 3 type's of inertia, you can change the characteristics of the motor for each circuit.

For example, model 1 with a highest inertia reacts slower on the gas throttle when turning out of the corner. The great advantage is that the rider can open the gas throttle earlier. The risk of spinning of the rear wheel will be a lot smaller. Another advantage of the higher inertia is that the topspeed will increase due to the increased and improved overrevolution characteristic. This crankshaft is heavier then the standard Honda crankshaft, but the crankshaft is designed so that the inertia has increased relatively more then the mass of the crankshaft.

The crankshaft with a lower inertia reacts faster, which will increase the acceleration of the bike. On short and slow racetracks, we advise to use the crankshaft with a lower inertia. Here you can find a chart of all crankshafts for the Honda RS125.

All VHM crankshaft has began a heat treatment and has been CNC grinded to precise dimensions. The advantage of the heat treatment is that the crankshaft in totally will be a lot stiffer, because the resistance against bending of the crankshaft is much bigger. This results in a much longer performance and the crankshaft can also be overhauled many times.

To obtain maximum performance, the service limit for the VHM crankshaft is 1200 km running. VHM can rebuild the crankshaft. The crankshaft will be disassembled and the connecting rod, big end pin, needle bearing and side washers will be replaced. After assembly, the crankshaft will be aligned with high accuracy.