09-09-2016, 03:46 AM
(09-08-2016, 10:48 PM)The ferret_imp Wrote: rotor what does" and power to travel-mass ratio of 150 w/kg minimum and 200 maximum" mean? I am not familiar with this specification.The usual "power over weight" (it should be "power over mass", but let's ignore for the moment those that do not understand the difference between "mass" and "weight") quotient takes into account only the mass of the vehicle. However, when it comes to acceleration, it makes a whole lot of difference whether some particular motorcycle is ridden solo or with a passenger. Since I'm hardly ever riding with a passenger, the power over mass measure that makes sense to me is the power over the mass of the vehicle, the rider and the cargo.
As an example, my current bike has a curb mass of 215 kg, and I (with the full gear and a bag I normally carry on a trip) have a mass of 100 kg (give or take). So the traveling mass is 315 kg. The plant of that bike outputs 57 kW (some 70+ horsepower IIRC, cf http://www.onlineconversion.com/ if you prefer imperial measurements) and thus the power/mass quotient is 181 W/kg. For me, this bike is both powerful enough (when ridden solo!) for decent acceleration in urban traffic, as well as light enough to be maneuverable; it is also heavy enough to be steady in quite a bit of cross-wind on a highway and fast enough to make it possible for me to decide where I fit in a fast, divided highway traffic.
Two more things on this measure:
With a passenger, (total mass 215+220, as per manufacturers specifications) my current bike would have 131 W/kg. This is inadequate, based on my solo riding experience with either Honda shadow 750 (96 W/kg) or Honda CB500F (126 W/kg). And no bike powerful enough for two-up riding with necessary minimum of power/mass would be light enough for me to handle in dense urban traffic. But for me, it hardly matters: I ride with a passenger so infrequently that I can make any adjustment I feel necessary.
These numbers are based on my own experience and riding style. YMMW.