Quote:
Originally Posted by sendler
Here is an interesting quote by DieselMaxPower at the Honda site which explains the conundrum of the power at the rear wheel not being multiplied by using a lower gear even though the vehicle does accelerate much faster. An example would be The CBR250R with an engine power peak at 8,700. If you are rolling along at a steady speed in first at 8,700 rpm, and then crack full throttle, the bike will accelerate violently. We can feel this very obviously. Now do the same in top gear. The bike is felt to start going faster but the rate of acceleration is much, much less. Even though we used the same amount of power from the engine and at the wheel. The acceleration is much greater with the lower gearing but we have put the same amount of power to the ground over time as in the higher gear. There must be some quantity that is increasing at the same rate in either gear (disregarding the higher resistance of speed to wind drag in top gear).
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Here's the problem... you can't disregard air resistance at higher speeds. That's like saying granite would float in water if you disregard gravity.
In top gear, you use a significant amount of your power due to wind resistance and friction. Only the remainder is used to accelerate the vehicle. Since you have less available power to accelerate the vehicle, you will accelerate slower.
It is also more "violent" in low gears because you have more torque at the wheels which is more likely to get the tire to lose traction or for the reaction to lift the nose of your vehicle upwards.