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Old 08-20-2017, 11:20 PM   #30 (permalink)
The Toecutter
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Join Date: May 2010
Location: Ghettoville, USA
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Rebellion - '16 KMX Framekit Custom electric velomobile
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Quote:
Originally Posted by Bicycle Bob View Post
J. Baldwin, long-time tech editor of Whole Earth Review, says that it usually takes three tries to be satisfied with a new design. The second prototype fixes up the obvious problems with the first, and the third smooths out most of the remaining irritations.
I have sort of figured this project wouldn't be completed until at least the 3rd body. I do want the first one to be at least usable and practical with a decent drag reduction. That's why I've been taking my time with it. I'm only designing to cruise at 30 mph or so, but the high top speed will be a consequence of gearing to do 30 mph with a cadence of 80-90, when I'm still capable of holding a cadence of 140 for shorter durations. I know of a KMX build with a 6.5 kW middrive though and it's rider can safely cruise at almost 40 mph and has been taken to 60+ mph a few times. The steering knuckles and stock wheels are the weak points of the KMX frame kit when it comes to tolerating road imperfections and hazards, but the knuckles can reliably handle cruising at 30 mph or so *IF* you have a front suspension setup, according to this builder.

I'm also partially inspired by the efficiency that Cedric Lynch has achieved in his electric recumbent motorcycle, roughly 30-40 wh/mi to do 50+ mph:




Adding a small amount of human power to that will yield more than marginal improvements in efficiency, and pedal power is awesome for extending your possible range to the point that even if you somehow cannot get electricity anywhere, you'll be able to still go anywhere that you can pedal it. It must be light enough to be pedaled, and geared so that at least a fit rider could climb steep grades at 4 mph. I think 100 lbs or less is a good target. There's a lot of efficient custom-build vehicles out there that are too heavy, but are worth drawing ideas from.

Adding some ass-hauling capacity with an overpowered drive system would make the vehicle fun and more appealing to hoons, and less prone to getting laughed at by the general public, as well as the practical application of being able to get away from a dangerous situation as well or better than most cars.
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