The Sun Trip has to be one of the most grueling eco-adventures and rallies where e-bikes race against time for 100 percent solar recharging ability. The sheer level of raw testing of machines against the elements, with no support crew or vehicles during the expedition, is what makes this Alpine adventure reserved only for those who are deep in their roots of engineering.
The eco adventure requires the e-bikes to go through mandatory checkpoints via designated regions, or pick their own routes. There’s no scope for any repair assistance or night camping provisions. One rule that’s crystal clear is that you never touch grid electricity during the course of the competition; otherwise, you are disqualified for the solar leg. Since 2013, the event has run successful editions in Europe, Central Asia, China, and North Africa.
Designer: Shawn Boden Ryan
This year’s Alpine edition saw an interesting e-bike powered by a solar panel array mounted on the front of the ride. The man behind the build is Ryan, who took a salvaged Omnium cargo bike with a sizeable front rack panel and turned it into a solar-powered ride for the competition. The first task was to remove those big panels and make way for a very unique 200W solar power array connected to the Genasun GVB-8 boost MPPT single charge controller. This was then mated to the two 36-volt batteries – one of them from EM3-EV, and the other from Infinit. Doing the heavy lifting in the setup is a 250W Tongsheng TSDZ2B mid-drive motor from Varstrom.
Since the amount of energy generated by the solar panels is a premium, the setup runs perfectly in this configuration. Keeping the overall weight down to a minimum was essential; therefore, even with the camping gear, camera equipment, and other essentials, the bike clocked just under 135 lbs. The changing spectrum of weather during the course of the competition was a big challenge, as the heatwave proved to be a big challenge. One of his batteries – the Infinit modular – took the onslaught of 41 degrees Celsius. “The BMS was essentially doing its job and protecting the battery, but it meant that for periods of the day I couldn’t store all the solar energy the panels were producing,” Ryan said.
The handicap forced him to plug into the grid for 1kWh of energy harvesting, which automatically put him out of the solar-only competition. On the good days, the 200 W capacity proved enough to power his bike through, but scope for things going wrong was pretty thin. Even if the battery would not have failed, it was anybody’s guess if he would have managed to make it through the solar-only competition. That I say because Ryan himself admitted that, “250W Tongsheng did struggle thermally on some of the really long climbs.” Learning from those little outcomes, he is already redesigning the concept bike for the Sun Trip from France to China in 2028.
He is considering shifting from a cargo bike to a long-wheelbase semi-recumbent layout. The solar bike will have the rider seat considerably further forward, topped with the wide solar canopy. This will increase the solar area, boost the aerodynamics, and make the ride more comfortable over long distances.
