The figures speak for themselves: According to the European industry association CONEBI, the bicycle industry is growing steadily, from annual sales of five billion euros more than 20 years ago to around 15 billion in 2019 – a development that has been further fueled by the pandemic. The market around e-bikes in particular is booming, with 43.4 percent more of them sold in Germany alone last year, according to the ZIV, the German two-wheeler industry association. After all, e-bikes fit the zeitgeist: They make it possible to cover distances quickly without many fellow travelers, and at the same time are more sustainable and climate-friendly than many conventional means of transport.
The heart of e-bikes are the batteries. Evonik's pyrogenic metal oxides AEROXIDE® are particularly effective in lithium-ion batteries: As a ceramic coating of a separator that separates the cathode and anode in the batteries, they ensure thermal stability even when heat is generated and help prevent a short circuit. In addition, AEROXIDE® support higher cycle stability, meaning the number of times a battery can be recharged. "The metal oxides help improve battery safety, usability and performance," summarizes Frank Menzel, director of Applied Technology Specialty Oxides.
The durability of components is another factor in high-priced e-bikes. Thanks to the better friction and wear properties of the VESTAKEEP® PEEK polyetheretherketone molding compounds, high-tech plastic gears have lower abrasion than conventional metal gears – and are also lighter and quieter. Properties that mean the high-performance polymer can also be used in parts of bearings. "For us, the e-bike segment is a growing market. We see a lot of movement and estimate the potential to be relatively high," explains Dr. Steffen Kanzler, Marketing Manager Europe VESTAKEEP® Transportation.
While the pandemic has created a boom in cycling on a recreational level, the amount of canceled competitions during the pandemic has been a real challenge for professional cyclists. Now there is hope for a season that can get back on track, at least with restrictions. To achieve the best times, the weight of the bikes plays a major role for the pros – helping that the energy generated by the racer is not lost. Manufacturers in the pro segment produce bicycle rims that weigh less than 1,000 grams per wheelset – thanks to a top layer of carbon and a core made of ROHACELL® rigid foam, which Evonik has been producing in Darmstadt (Germany) since the 1970s.
The top layer consists of fibers and resin. During construction, the resin is liquid. Pressure and heat must be used to get it into the right shape. "The higher the pressure and temperature, the better the quality of the top layer," explains Felix Goldmann, ROHACELL® Market Segment Manager Lifestyle. "ROHACELL® is particularly resistant to temperature and pressure. Thus, one can create a very good, robust top layer at a very low density of the foam core – which just remains light."
As important as the inner values of a bicycle are: Ultimately, the appearance also plays a role. A matte finish in particular makes the bike an eye-catcher. This is where SPHERILEX® comes into play: as part of the powder coating, the spherical silica with its matching round shaped particles improve the hardness of the coating, while the paintwork remains flexible. The cycling thus also becomes a visual pleasure.