Transition index: This is intended to support simulation for shifting gearbox models. In this case the numerical index (cell C23) marks the shifting point in the simulation.
Selected operating point: This is intended to provide a snapshot of the system values at a particular time-step. Changing cell H12 will update the time point, the data values in H14:H34 will then also be updated.
Human command: This is intended to model the extent of the command from the driver, I think this should remain 100%; I.e. “go fast as I can”.
Your question is modeling of custom gearboxes.
Look at the Gearboxes.
On that page you will see all of the modeled gearboxes.
At present, there is one space identified as “custom”. The present custom gearbox defines a single stage gear reduction.
Most likely way to model a custom gearbox is to start with an existing gearbox and start changing the gear selections - this will change the gear ratio. Be careful! Not all selections can be built!!
Once you have updated the gear ratio: go back to the UserInterface tab, Change both the Low Speed (cell C20) and the High speed (C28) to the gearbox you want to consider.
There are other ways to do this, but I think this is the most straight forward.