Is primary drive ratio normally included into the gearbox ratio specification, or should it be considered as a sum of the two to get the true ratio?
Lets take a modern BMW motorcycle engine as an example - what would be a gearbox output ratio at i.e. 1st gear - 2.38 or 1.73*2.38 = 4.11?
Gear Box 6 speed
Primary Drive 1.73:1
1st Gear Ratio 2.38:1
2nd Gear Ratio 1.65:1
3rd Gear Ratio 1.30:1
4th Gear Ratio 1.07:1
5th Gear Ratio 0.96:1
6th Gear Ratio 0.84:1
Final Drive System Enclosed driveshaft with
universal joints
Final Drive Ratio 2.9