Backstory of my solar ebike

A brief history of my solar ebike…

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In 2006, I completed a 2 month, 2000 mile (3200 km) fully loaded bike tour of Italy.
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I had a solar backpack to charge my phone and batteries for lights.
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When I passed through Cinque Terre, I noticed these solar panels on the roof of a train station and had an idea.

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When I returned to California, I started researching solar vehicles and found a lot of this.
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And a little bit of this.
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So I started sketching out ideas.
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I got a tadpole trike and started experimenting to get an idea of what was practical.

My first attempt at building a custom solar panel was instructive but the cells all cracked during the lamination process and the panel output was too low to be usable.

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It looked kind of cool, though.
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I found some off-spec satellite-grade dual junction gallium arsenide cells on eBay. The seller was in Mountain View, California so I like to think these were leftovers from a NASA project.
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In 2008, I got my first taste of success with this 50 watt panel.
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I upgraded the bike to this 2-wheeled model with suspension and higher seat height for commuting 20 miles a day in traffic. The tail-box fairing was a bit awkward.
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Later, I experimented with a curved front fairing design using a commercially made semi-flexible panel.
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After a dozen or so overnight camping trips, I knew I needed more solar to get the daily range I was looking for. I didn’t want the high center of gravity and cross wind issues an overhead solar panel would bring so I started experimenting with a trailer solution.
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Thanks to an extra battery and a manually operated panel tilt mount, I set a personal single day distance record of 144 miles (232 km) by traveling from Oakland to Pinnacles National Park.
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I set out to improve on the trailer design by making a one-wheeled trailer from scratch. This first attempt used undersized aluminum tubing and connected to the rear bike rack, causing it to flex like a wet noodle while riding. Not good.
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A larger diameter tube with carbon fiber reinforcement fixed the flexing problem. An elastomer suspension smoothed out the rough spots without adding too much weight. And a linear actuator added motorized tilting while riding to get more energy.
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A few more tweaks and she’ll be ready for the ultimate test ride.

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