Imagine a race where the only rule is not to touch a power outlet. This is Sun Trip, a test of endurance and engineering ingenuity where participants must rely entirely on solar energy. This year, the Alpine stage of the competition saw an unusual contender: a cargo bike converted into a fully autonomous solar-powered vehicle. Sean Boden Ryan, an enthusiast engineer, took a used Omnium cargo bike with an impressive front cargo platform as his base. His task was to transform this workhorse into a machine for long journeys, where every watt counts. The standard panels were removed from the front, making way for a unique 200W solar installation. This system is connected to a Genasun GVB-8 boost MPPT charge controller and powers two 36-volt batteries. The "heavy lifting" is done by a 250-watt Tongsheng TSDZ2B motor integrated into the bottom bracket. A key factor for success in such races is minimizing weight. Even with camping gear, photo equipment, and other necessary items, the total weight of the bike was just under 61 kg. However, as often happens in survival races, the weather made its own adjustments. The heat became a serious challenge: one of the batteries, an Infinit modular, was exposed to a temperature of 41 degrees Celsius. "The battery management system (BMS) was doing its job, protecting the battery, but it meant that during certain hours of the day, I couldn't store all the energy produced by the panels," says Ryan. This incident forced him to connect to the grid to charge 1 kWh, which automatically disqualified him from the "solar" stage of the competition. Even on the best days, 200W of solar power was enough for movement, but there was little margin for error. Ryan admits that the Tongsheng motor also experienced thermal loads on long climbs. The experience gained on this journey is already pushing him to rethink the concept. For the next Sun Trip from France to China in 2028, he plans to abandon the cargo platform in favor of a long-wheelbase recumbent layout. The new bike will have a more forward-positioned seat under a wide solar canopy. This will increase the energy collection area, improve aerodynamics, and make the ride more comfortable over long distances. Essentially, it's a step from a cargo bike to a true solar motorhome for extreme travelers.