Michael Polak


– 44 years-old – Czech Republic


Lagging behind in 2015 with a bamboo-fitted solar bike, he’s back with a completely rethought machine!

Michael’s goal is now to ride a daily average of more than 200 km on the 12 000 km between Lyon and Guangzhou.


The Solar Bike:

Bike: This lowrider recumbent is a prototype – Lenochod-1 built by Cargobikes.cz  and based on a custom multi-purpose space frame configurable either as long haul lowrider or as heavy-duty urban cargo bicycle. Fully suspended, it is equipped by lightweight aluminum aerodynamic shields. It’s length is 270 cm (without cargo box).
Motor:  Generic Chinese direct-drive 1 kW imported by E-pohon.cz used with regenerative braking.

Motor controller: ESC3-AM sine-wave prototype built by PearControl.cz and provided by E-pohon.cz. It is probably based on vesc-project.com (originally designed as Electric Skateboard Controller – ESC).

Battery: 48V 21 Ah Li-ion prototype built by JV-Labs.EU and sealed in 3D printed container, includes built-in Chinese BMS

Solar panels: all monocrystaline – 2 horizontal panels (79 x 130 cm, total 380 Wp) visible while riding. Panels are connected using a generic MPPT charge controller. Solar roof is easily removable and is equipped with a front bumper enhancing pedestrian safety. Solar roof struts are shaped to provide additional safety for both rider and solar panels in case of tip-over.

Some words from the adventurer…

I like traveling to places which I never visited before and which I may never visit again in my life. I tried many different modes of budget travel, of which being independent traveler with backpack was probably most interesting – especially when I managed to go off-the beaten path. But of course, I was dreaming of travelling even more independently and autonomously, not just by trains, buses and rented scooters.

I am not trained enough to really enjoy conventional long distance bicycle rides where one carries all its luggage and camping equipment, but I was intrigued by the idea of solar bicycles as soon I stumbled upon videos featuring them on YouTube, maybe as soon as 2010.

I built my first solar-charged vehicle based on a second hand 36V e-bike and trailer in 2013, but it was complete failure – it disintegrated many times during just my 1300 km test journey, although it did cross the Great St. Bernard pass in Switzerland. Another attempt was with a 24V tandem bike with a bamboo solar roof, which made a 8000 km journey in 2015 during the Sun Trip 2015, and a more conventional CT2 cargo bicycle, recycling spare parts that survived the tandem project with smaller solar panels covering a huge aluminum cargobox.

Cargo bicycle development and innovation may be an interesting side effect of solar bicycle development: carrying larger amounts of useful load on an electrically-assisted bicycle in a urban environment is surprisingly similar task to carrying lots of luggage and solar panels on a bicycle trip. The necessity of finding innovative clean solutions for logistics in congested and polluted cities is obvious, and e-bikes are much more readily available, compared to larger electric cars, trucks and buses.

I am generally interested in renewable and alternative power sources and I was trying to obtain hands-on experience using solar power even before building my first solar-powered vehicle.

Also, since childhood I was dreaming about designing various types of vehicles, so this solar bicycle hobby basically connects a mature desire to travel with a childhood dream of traveling the vehicle of my own design. The design of my Lenochod-1 lightweight steel space frame cites late 19th century engineering, Art Nouveau and also early airplanes and airships.

The name “Lenochod” is the Czech word for sloth, an animal that lives in Central and Southern America. In Czech, we typically invent words for plants and animals from all over the world, even if they are not native to Europe. This word literally means “lazy walker” and it is quite similar to the Russian word “Lunochod“, which was name of their quite successful unmanned lunar rover in 1970’s. Also, the Russian word for an all-terrain vehicle is “vezdechod“, with meaning close to “can walk/ride anywhere”. As the Russian name for the sloth/bicycle would be “Lenivec” (“the lazy one”, like in Czech) Russian speakers that I encounter may or may not understand the meaning… who knows!

My ultimate goal is to design and build an autonomous, solar-charged and assisted ultralight airplane and change my mode of independent traveling from roads to air. This would require huge leap in energy efficiency and engineering skills, so for now, I’m only trying to catch-up with The Sun Trip rally level. Know-how and skills is the logical first step, before aiming higher.

Regarding Sun Trip 2018, I know, that I need a 6 Wh/km efficiency to be able to travel at least 200 km/day, with average speed exceeding 25 km/h. I don’t know if I will manage to achieve this goal, but I did my best to design my prototype solar bicycle to make this possible.

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