Calculating the crankshaft balance factor for your crankshaft 

Here the crankshaft balance factor is calculated for a single cylinder crankshaft.
The balance factor is what determines the vibrations on your bike.
The example here is for a Lambretta, but will work for any single cylinder 2 stroke engine.
At the end of the video we compare the balance factor of an old crankshaft to it's replacement.