The crankshaft is the hearth of the engine. In our beloved V twins they are put together from different components as the drive shaft, flywheels, crankpin and pinionshaft. It is essential that these are put together in perfect geometery. Both shafts and crankpin must be inline and squared in relation to the flywheels. This is done by checking and if necesary remachining the tapered bores in the flywheels and/ or tapered sides of the crankpin. It is even important to check and/or remachine the threads and nuts on both shafts and crankpin. When put together it's truied in a set up as seen on the photo above. The weight of the flywheels is supported by special fabricated v blocks, instead of center which are commonly used. So the weight of the flywheels won't affect the reading on the dials.