Introduction
Engineering and vehicles have always been an interest of mine. The very idea that there could be a vehicle that can travel without burning any petrol was very intriguing. I always wondered about the possibilities, and even did some calculations. But because solar vehicles didn’t exist I assumed that there must be a reason, probably because they aren’t practical.
That changed when I saw a solar tricycle parked in the front of the bed&breakfast of a hotel where I once stayed.
I learned about the Suntrip tour, and I decided there and then that I would one day be part of it.
It took a few years, but I have the opportunity to give it a try.
My intention was to enter into the 2020 edition. I didn’t care about being competitive, I just wanted to prepare with the least budget I could. I even purchased a tandem bicycle and I intended to fit the solar panels and cargo space on the back.
My intention was to enter into the 2020 edition. I didn’t care about being competitive, I just wanted to prepare with the least budget I could. I even purchased a tandem bicycle and I intended to fit the solar panels and cargo space on the back.
I wasn’t interested in fighting to get a sponsor because I wasn’t comfortable with the extra pressure. The event looked very stressful and dangerous, so I didn’t want some marketing person to have a say in my on-the-road decisions.
I knew that a velomobile would be faster, but I didn’t know how much faster. And the price was very prohibitive.
However I ran some python and matlab simulations using the expected course to China, and the results were astonishing. On a 10000 km course, according to the simulations I would gain 6 days with a velomobile compared to an upright bicycle.
That moment the decision was simple. It was just a matter of finding a velomobile to compete with.
Soon enough I found a used velomobile, and I changed my whole strategy.
The vehicle and its electrical equipment
The vehicle is a standard carbon quest. Not an extremely fast vehicle by today’s standards, but very practical and with potential.
I devised some mounts, put the order in for the solar panels and put together all the details. I knew I had very little fabrication experience, but I did not let that deter me.
The vehicle did have a drawback: there was no way to use a hub motor. I hoped it would not be a problem, and indeed, it made the vehicle more efficient with low solar production, but not being able to regen was a problem.
Also relying on the gear shift too much was going to be difficult. Both for comfort and for reliability. A hub motor would have been so much easier.
I have found a chinese manufacturer that agreed to fabricate a special batch of 11×7 cells panel. The price was also excellent.
I also didn’t want to buy an expensive genasun MPPT controller, so I bought 2 development boards from aliexpress:
LT8490: dedicated MPPT tracking boost controller, about Euro 50
LT8705: constant input voltage controller, about Euro 44
Sadly before my departure LT8705 failed catastrophically, in a big flame. I quickly purchased a genasun so I can start the event.
LT8490 however proved to be extremely efficient and reliable. It was even more efficient than the Genasun. I did purchase extra aluminium fins that I attached to the aluminium case to manage the heat.
Repairs and modifications
In Riga I went to a fabrication shop because my aluminium top mounds broke. They did the job in about 2 hours for 50 euro
At my parents house in Romania I replaced the rear tire. After many many kilometres it was still rubbing against the body, so it was best to use a thinner one. I also added a fan for the motor and for my legs.
In Italy, the front rims developed a longitudinal crack. That got worse and worse, and it led to excessive wear. I never fixed them, and it took me a long time to realise what was the issue.
The cable hoses of one of the brakes started sticking, due to excessive heat. This led to even more heating and loss of efficiency.
In Porto the main derailleur spring broke, and I was stuck on the shortest gear. To make things worse, it was lunch time, so I had to wait 3 hours until the bike shops opened.
The last two failures would have never happened with a hub motor. I knew the risk, but I had no choice.
Futur project
Sadly with the current political climate a big adventure would be difficult (Russian war, China closeness to foreigners). So I’m not planning anything at the moment.
The trip also made me realise how dangerous riding on the road is, so lately I’m trying to avoid it. Rather spend time on the trails away from the traffic.
Should another international Suntrip opportunity arise, I think I would jump in.