Quote:
Originally Posted by darcane
However, your example is still misleading because the effects of aerodynamic drag increase exponentially and very quickly dwarf the power needed for acceleration.
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Hi darcane,
OK, misleading. I was going to have a chart showing power for RR cdA and acceleration all vs speed with limits and stuff. It is kind of a mess, here it is. This is for a 600 lb bike with A=5 sq ft and cdA= 0.5 - assumptions: 100 hp available from engine, excess hp goes to accelerate the bike - which is crazy at 10 mph it only takes 16 hp for 1 g.
Code:
speed HP Aero RR Accel hp for [accel using
MPH total hp hp hp avail 1 g avail hp]
10 100 0 0.2 99.8 16 6.2
20 100 0 0.3 99.5 32 3.1
30 100 0 0.5 99.1 48 2.1
40 100 1 0.6 98.3 64 1.5
50 100 2 0.8 97.1 80 1.2
60 100 4 1.0 95.3 96 0.99
70 100 6 1.1 93.0 0.83
80 100 9 1.3 90.0 0.70
90 100 12 1.4 86.1 0.60
100 100 17 1.6 81.3 0.51
110 100 23 1.8 75.5 0.43
120 100 30 1.9 68.5 0.36
130 100 38 2.1 60.4 0.29
140 100 47 2.2 50.8 0.23 <-- aero and accel hp about equal
150 100 58 2.4 39.9 0.17
160 100 70 2.6 27.4 0.11
170 100 84 2.7 13.3 0.05
180 103 100 2.9 0.0 <-- top speed
So at 100 mph you have 81 hp available to use to accelerate. Which allows about .5 g
-mort