Car meets e-bike: riding with lubrication-free polymer bearings

E-scooters, e-bikes, small electric vehicles: there are numerous car alternatives on the market for the transport revolution. Consumers are correspondingly critical when making their choice. What would be the right vehicle for the summer? The tipping point is often the issue of maintenance. For example, who wants to clean and lubricate numerous bearing points on a daily basis in order to get to work on time? That's what the designers at JetBike GmbH in Braunschweig had in mind when they developed the JetBike: a car-like e-bike with a full fairing that people can ride without a driving license, tax or insurance.

Classic metal bearings as a buzzkill

The experts suspected that classic metal bearings could cause problems in the mechanics of the vehicle. "In city traffic, there is always the risk of dust and dirt getting stuck in the metal bearings and making smooth and quiet running impossible," says Enno Hecker, Managing Director of JetBike. The constant risk of corrosion and the issue of relubrication are also unloved companions. "We therefore decided to replace the metal bearings with lubrication-free polymer bearings from Igus ."

Polymer bearings from the Iglidur series from Igus can be found everywhere in the JetBike. Cylindrical plain bearings made from Iglidur G are used, for example, in the steering and on swivel joints in the chassis. The engineers used variants with a collar for the seat backrest adjustment, among other things. Igubal rod ends and spherical plain bearings enable complex motion sequences, for example in the articulation of chassis components. The flange bearings make it possible to attach bearing points flat to the frame, for example on the hood or boot lid. The patented tilting system also uses 3D-printed sliding elements made from the SLS material Iglidur i3. "The collaboration with igus was very efficient and pleasant, as the company took us seriously as a start-up with initially very small quantities," recalls Enno Hecker. "It was therefore possible, for example, to realize special bearing sizes and adapt them precisely to our vehicle without any problems. This service at eye level significantly accelerated our design process."

Polymer bearings: no lubrication and a smoother ride

The polymer bearings have a number of advantages. Firstly, they do not require lubrication. Microscopically small solid lubricants in the material enable low-friction dry running. "The bearings are therefore significantly more resistant to dirt, more fail-safe and completely maintenance-free. That was exactly what was important to us," says Enno Hecker. In addition, owners do not need any lubricating greases, which are often_{CO2-intensive} to produce. Secondly, the polymer bearings have damping properties. This results in a smoother ride over bumps in the road. Thirdly, the bearings are robust. They deform elastically under high loads instead of being damaged. This also increases the reliability of the vehicle. Fourthly, the polymer bearings are up to 80 percent lighter than metal bearings. This weight saving helps to increase the range of the electric vehicle. Due to these many advantages, the investment in the polymer bearings, which are also up to 40 percent cheaper than metal bearings, pays for itself very quickly. The start-up is currently developing a near-series prototype of the JetBike.