safe wrote:I know that this is an "Electricity" based messageboard, but when you go about designing an electric bike you have to decide whether aerodynamics are going to be a factor or not. The simple fact of the matter is that the legal limit for most electric bikes is 30 mph or in many cases 20 mph. At those low speeds aerodynamics have almost no effect. Above 30 mph the effects of wind resistance predominate to such a degree that you can almost factor out other issues. (like losses due to gearing, tires, etc..)
Let's see if there are ideas or opinions about this:
Should the electric bike designer ever concern themselves with aerodynamics?
Maybe designing for aerodynamics is a confession of guilt for breaking the law?
The statement that aerodynamics have almost no effect at these speeds is so wrong, at speeds above 30 kph wind resistance is 80% of the resistance to forward motion.
Using the http://www.kreuzotter.de/english/espeed.htm
a MTB at 160 watt input will achieve 16.3 mph, whereas the same wattage on a velomobile (Quest) will achieve 25.6 mph.
Put another way the MTB will require over 3 times as much power (over 500w) to achieve the same speed.
Real world my GT3 trike which is much, much lower drag than a MTB, but putting a shell on it increased speed from 48 kph bare upto 63 kph on a control hill that I can easily replicate a no pedal speed, and my shell is optimised for practicality rather than speed.
Oh and if you throw in a 20 mph head wind it is barley discernable in a velomobile, how about on a bike?
Velomobiles are slowly starting to increase world wide as people realize all the benefits, speed being one of them.