[sendler]

This has been very fun so I guess that makes me a serious Geek. I would much rather be spending my time studying physics than watching a movie even though my only formal training is a very rusty NYS High School algebra based physics class from 30+ years ago. I really appreciate the time and effort of everyone who is reading and or contributing to the discussion.
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The physics we need to understand are really very simple. Reciprocating engines make Torque and when looked at by multiplying that by the Revolutions (How many "Torques") in a certain amount of Time, you get the Power of the engine.
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Rear wheel Torque is Force on the road. But it is interesting to note that the highest rear wheel Torque will occur, ie with a constantly variable transmission, which is set to the Power peak of the engine. Not the Torque peak. Due to the fact that it will be using more torque multiplication (lower gear) at the higher rpm of the power peak.
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Force (from the rear wheel Torque) times the Distance the bike moved is Work.
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Power is the measure of Work vs Time. If you do the same amount of Work in a shorter Time, you have used more Power.
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P=W/T
Work=Force*Distance so
P=F*D/T and D/T is Velocity so
P=F*V
Given the same Power from the engine, The Force at the rear wheel must be less as the Speed between the road and the bike increases.
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F=M*A
Acceleration = Force/ Mass
F, and therefore A, must be less and less as the speed difference between the driven wheel and the road, or the airplane propeller and the air, is increasing.
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So this is the "Captain Obvious" over complicated way of saying the bike will pull harder in 1st than in 6th.
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It is fascinating to note also that the Propeller in air follows the same theory. It pulls harder at 100 mph than it does at 240 mph. Note also the the efficiency for this prop at 100 mph is only 64% versus 85% at 240 so the slope of the thrust drop off would be even steeper if real world efficiency were left out.