A Ducati Diavel with over 1,500 Nm of torque at the wheel, but …

by Matteo Accurso (Polimi Motorcycle Factory)

Generally, in the technical data sheets of motorcycles with traditional internal combustion engines, the torque values ​​at the crankshaft are indicated, which for a 1,000 cc vary between 90 and 160 Nm. Verge for the TS, its electric motorcycle with the engine integrated into the rear wheel, declares 1,000 Nm of maximum torque delivered (although it does not specify at what speed this figure is reached). However, we must be careful because this value, which may seem disproportionate, must be contextualized.

Take, for example, the Ducati Diavel 1260 (which we also quote as a comparison in the Verge TS test): we have 118.4 Nm for it at 7,400 rpm at the wheel (data collected by our test center). What we commonly indicate as the value to the wheel is actually the value that the roller bench calculates at the hub, based on the various losses due to the transmission: the primary one, that of the gearbox (its value depends on the gear engaged) and the final compound. from chain, pinion and crown. For example, the Diavel has a primary transmission ratio of 1.84, the final one of 2.86 and an internal ratio in first gear of 2.46. If you calculate the maximum torque value of the Diavel in first gear then (or 118.4×1.84×2.86×2.46) you get a value of 1,532 Nm. And this is what the bench detects at the point of contact of the tire with the roller, that is, where the angular speed of the wheel is measured. Since the electric motor of the Verge cannot count on the torque transformation given by the mechanical transmission (it is itself a rotating element), if we could put it on the test bench, we would not have to enter the values ​​of the transmissions (which are not there) and therefore the bench it could register a torque of 1,000 Nm at the point of contact between rubber and roller, comparable to that of a modern 1,000 cc.

To conclude, let’s take a practical example: since 1,000 Nm equals 101.972 kgm, it is like saying that we have a weight of almost 102 kg on a 1 meter long lever. All clear?