Introduction
You will find descriptions in this article:
- of the first version we both participated in the SunTrip 2015 (7500 km).
- of the second version of Beatrice’s bike after the one -this has suffered serious damage.
Feedback after 60,000 km has allowed for significant improvements..
Bicycles
We decided to use our mountain bikes, mid-range full suspension bikes from Decathlon.
The battery
The 1000 Wh battery (48  ;Volts – 20 Ah) is Lifepo technology, a technology chosen for its resistance, safety and longevity. The disadvantages are the weight and the price. We bought cells that we wired and we added the BMS.
Solar Equipment
The solar panels are commercial panels found on the Internet (Wattuneed). Additional panels were mounted on slides. Our solution then includes 240 Wc permanently exposed and 200 Wc deployable when stationary, which gives an average of 340 Wc They are adjustable, as they are mounted on a longitudinal axis, in order to optimize solar charging when driving in light winds. The orientation also allows access to luggage.
For solar controllers, we used Victron 24V Step-up Bucks, high quality for a reasonable price, instead of the only boost available in 2015, the Genasun 48V, which we found too expensive.
The trailer
The trailer
The upright bike involves the use of a trailer that carries the luggage and the solar panels. The choice fell on a single-wheel trailer which has the advantage of stability at high speeds downhill and which allows fine steering on poorly passable roads. It had to be suspended to protect the panels from vibrations and it had to be attached to the seat post in order to take advantage of the rear suspension of the bike. For the resistance we decided to get a high-end commercial trailer: the AEVON STD 120.
Feedback after more than 60,000 km, in 2024
Positive points
- Solar panels: they still provide their peak value when the conditions are good.
- Orientation of the panels: we have made their orientation easier by motorizing it using a Clio window lift motor.
Points to improve
- Motorization: we installed a second motor on the front wheel, identical to the rear wheel motor. Indeed, a single motor is not enough to take a crew of almost 200 kg up mountain passes without overheating. Since we have been using two motors, we have not had to replace them due to overheating.
- Retractable solar panel slide system: it is fragile, they must be changed regularly.
Technical description of the second version – spring 2024
Observation
During the Sun Trip Alpes 2023, Béatrice’s bike suffered major damage: a gust of wind at the Stelvio Pass (2,758 m) overturned the trailer, breaking the additional solar panels, and on the way home a hailstorm damaged the panels that were still exposed, causing them to lose 30% of their power.
These technical problems provided an opportunity to completely review the design.
The motorization
The motorization remains the same: a motor on the front wheel and an identical motor on the rear wheel (400W each).
The battery
We decide to abandon the Lifepo battery technology to switch to the classic Lithium-ion technology, which is cheaper and lighter. We choose a battery with a higher capacity: 1200 Wh instead of 1000 Wh. The weight is halved: from 12 kg to 6 kg.
Solar equipment
Solar panels:
The drop in prices has made it possible to order custom-made panels directly from a Chinese manufacturer. The new system is a little more bulky – 6 cells in width instead of 5.33 – but more compact than the first version. In use, this second version is slightly more favorable than the first in terms of average load.
We are abandoning the slide system. So, there will no longer be retractable panels, but the bike will have 360 Wc permanently exposed, instead of the average 340 Wc of the first version.
In addition, Boost technology solar regulators have appeared on the market at very affordable prices (Chinese regulators). We are abandoning the Victron Step-Up regulator.
The trailer
The total weight of the empty trailer drops from 50.7 kg to 39.5 kg, a saving of 11.2 kg or 22%. For the record, the bike alone equipped with the motors weighs 27 kg.
For solar controllers, we used Victron 24V Step-up Bucks, high quality for a reasonable price, instead of the only boost available in 2015, the Genasun 48V, which we found too expensive.
The trailer
The trailer
The upright bike involves the use of a trailer that carries the luggage and the solar panels. The choice fell on a single-wheel trailer which has the advantage of stability at high speeds downhill and which allows fine steering on poorly passable roads. It had to be suspended to protect the panels from vibrations and it had to be attached to the seat post in order to take advantage of the rear suspension of the bike. For the resistance we decided to get a high-end commercial trailer: the AEVON STD 120.
Feedback after more than 60,000 km, in 2024
Positive points
- Solar panels: they still provide their peak value when the conditions are good.
- Orientation of the panels: we have made their orientation easier by motorizing it using a Clio window lift motor.
Points to improve
- Motorization: we installed a second motor on the front wheel, identical to the rear wheel motor. Indeed, a single motor is not enough to take a crew of almost 200 kg up mountain passes without overheating. Since we have been using two motors, we have not had to replace them due to overheating.
- Retractable solar panel slide system: it is fragile, they must be changed regularly.
Technical description of the second version – spring 2024
Observation
During the Sun Trip Alpes 2023, Béatrice’s bike suffered major damage: a gust of wind at the Stelvio Pass (2,758 m) overturned the trailer, breaking the additional solar panels, and on the way home a hailstorm damaged the panels that were still exposed, causing them to lose 30% of their power.
These technical problems provided an opportunity to completely review the design.
The motorization
The motorization remains the same: a motor on the front wheel and an identical motor on the rear wheel (400W each).
The battery
We decide to abandon the Lifepo battery technology to switch to the classic Lithium-ion technology, which is cheaper and lighter. We choose a battery with a higher capacity: 1200 Wh instead of 1000 Wh. The weight is halved: from 12 kg to 6 kg.
Solar equipment
Solar panels:
The drop in prices has made it possible to order custom-made panels directly from a Chinese manufacturer. The new system is a little more bulky – 6 cells in width instead of 5.33 – but more compact than the first version. In use, this second version is slightly more favorable than the first in terms of average load.
We are abandoning the slide system. So, there will no longer be retractable panels, but the bike will have 360 Wc permanently exposed, instead of the average 340 Wc of the first version.
In addition, Boost technology solar regulators have appeared on the market at very affordable prices (Chinese regulators). We are abandoning the Victron Step-Up regulator.
The trailer
The total weight of the empty trailer drops from 50.7 kg to 39.5 kg, a saving of 11.2 kg or 22%. For the record, the bike alone equipped with the motors weighs 27 kg.