The idea is so simple that it seems to have sprung from a child's brain. But the principle also works with the good old Velosolex: a motor-driven roller is pressed onto the tire and thus drives a two-wheeler.

The Kamingo eBike conversion kit is an electric motor with such a drive roller, which can be attached to the bicycle frame in a few simple steps and thus turns any bicycle into an e-bike. Well, almost any bike, but more on that later.

In the video, it looks totally simple. The motor is controlled via a remote control on the handlebars, which issues commands to the drive via Bluetooth. The battery is located in the bottle cage, whereby the one supplied is to be used. The motor and battery together weigh just 2.3 kilograms. Some e-bike batteries are heavier on their own.

Not compatible with rim brakes and carbon frames

Kamingo has a few restrictions, however: In order for the motor to be attached to the seat stays, there must be no brakes blocking the space - bikes with rim brakes are therefore not compatible. The part must also not be attached to carbon frames - which is even more unfavorable for mountain bikers. However, if you are on an aluminum bike, you could use the Kamingo for the ascent, then stow it in your backpack and drop it in the usual configuration for the descent.

The motor is said to deliver up to 750 watts. The control system reacts to the rider's pedaling thanks to a pedal sensor supplied. However, there is also a cruise mode in which the motor turns without the person in the saddle pedaling. The battery should last for up to 90 kilometers. Several Youtubers have tested the Kamingo. It seems to work, at least in the city.

According to the Kickstarter description, engineers who previously worked for Huawei and BYD are behind the compact conversion kit. And Kamingo, the friendly helper on the rear wheel, looks just as sophisticated as the products of the two top Chinese brands.

On Kickstarter, Kamingo has raised almost 1.4 million Swiss francs in just over six weeks. And backers can still pre-order a copy for 359 dollars instead of 589. Kits are due to be delivered in December. If you have ordered one, we would be very interested to hear about your experience.