Recycled cars get a new life as bike sharing docks

In a new article, automobile recycling organization Autoretur revealed how recycled aluminum from cars is making its way back onto the streets — this time, as an integral part of our bike sharing systems.

The new Trondheim City Bike, launched in May 2018.

In addition to reducing traffic congestion and carbon emissions by getting people out of cars and onto bikes, our latest dock design is now making bike sharing even more environmentally sustainable.

“For the contracts we won for Trondheim and Bergen, we designed the entire system from scratch, including bikes and stands,” says our CTO Johan Høgåsen-Hallesby. “The big change is that we have moved the lock — the mechanical and electronic components — from the dock to the bike. This allows us to operate with docks that are easier to establish and maintain.”

In this new system design, bikes can be locked both to the physical docks and within “virtual stations” via geo-fencing technology. At the top of the physical docks is what we call a flex pin, which is the interface that connects to the bike and which contains a magnet and a passive RFID chip. This enables us to detect which bike is in any given dock.

“With this we have created one of the first hybrid solutions, which brings the best from both dock-based and free-floating bike sharing,” says Høgåsen-Hallesby.

The sleek new physical docks, which are easy to install and minimally disruptive to the flow of the city, are produced by R-Metall and made of aluminum that’s been recycled from Norwegian freight cars. After a vehicle has been discarded, it’s driven through a shredder and the parts are torn apart and sorted by materials. The car’s aluminum parts are then melted down to become new products. In this case, aluminum bike docks.

The bikes can be unlocked from the docks with the tap of a button in the app.

Terje Mass Andersen, General Manager at Rolvsøy Metallindustri in Fredrikstad, purchases aluminum waste through the Autoretur system.

“When aluminum is first produced, the metal can be recycled for almost eternity,” says Andersen. Aluminum casting is dependent on so-called secondary aluminum, he explains, as unused aluminum is not moldable. Products that can be made from recycled aluminum includes awnings, car seats, and car radio frames. Now, bike sharing docks can be added to that list.

The recycling of aluminum provides energy savings of 38 kWh per kilo and a calculated reduction in CO2 emissions of ten kilograms per kilo. This means that material recycling of aluminum in rims and fragmentation plants reduced CO2 emissions by 78,600 tonnes in 2017, saving 299 GWh.

A circular economy

Autoretur reports that there is a great need for projects like this one, which helps to create circular economy. Aluminum is lighter than steel, which makes the installation and removal of our docks easier and also more sustainable, as it also reduces fuel consumption during transportation. Compared with steel, aluminum is also less corrosive, which makes it an ideal material for our docks, which must be able to endure a wide range of weather conditions.

As we expand to new cities, we need the ability to build stations rapidly, while also having the flexibility to move the docks as we adapt to the needs of the city. These sturdy yet lightweight docks made from recycled aluminum meet these needs perfectly.

“That old cars are being made into infrastructure for bike sharing really is a fantastic story,” says Høgåsen-Hallesby.

Read the full environmental report here. Read the entire environmental accounts here.


1) Gesamtverband der Aluminiumindustrie e.V (GDA)

2) Authors’ environmental accounts 2017 / Authors environmental report 2017