Recycling of an old bicycle into an electric bicycle

In December 2021, Rok Mohorič and Žan Pirih, 3rd year students of the mechatronics operator program, completed the conversion of an old bicycle into an electric bicycle in the subject of assembling and testing mechatronic systems under the mentorship of Andrej Kavčič, a practical teacher.

The bicycle, which has already been taken out of use, was obtained at the waste collection centre in Idrija. Since it already had a lot of missing parts, the students first finished and repaired the bike so that it was rideable. They later installed a 600W e-bike conversion kit on it, with the engine in the rear wheel hub. This was followed by the installation of a rechargeable battery on the wheel frame and the connection of the electrical installation with the installation of a sensor for detecting the speed of turning the pedals. The battery was bought with the funds from the Erasmus+ project R4MAD.

When assembling the kit, it was necessary to drill some new holes to attach the battery and widen the distance between the rear forks, as the hub with the electric motor is wider than the standard wheel. It was time to paint the frame, for which it was necessary to completely disassemble the bike again and clean it of stickers and old paint. After applying the base coat, they repainted it with dark blue metallic paint. Once the frame was dry, the wheel was carefully assembled by assembling new bearings, gear wires, and bowden brakes. They re-installed the battery, the rear wheel with the hub and the speed control panel on the bike’s handlebars. All that was needed was to fine-tune both gearboxes and the brakes and the bike was ready for a ride.

Students Rok Mohorič and Žan Pirih deserve praise for their innovation and ingenuity in bicycle processing.

The bike has aroused a lot of interest among students and there is no shortage of candidates for test drives. The electric bicycle will be available for use for the purposes of the Jurij Vega Grammar School.

This is an example of good practice in reusing used bicycles. During their work, the students also gained new knowledge in the field of assembly, electrical engineering and materials design.