Jump to main content
Press Office and Crossmedia Communications
University News
University News Research

The astounding bowbike

Ultralight and inexpensive: The three-membered entrepreneurial team „bowbike“ of the Chemnitz University is about to launch an extraordinary designed lightweight bicycle frame made of carbon fibers

The three inventors Sven Gläser, Hendrik Berthel and Leon Kontny of the Chemnitz University of Technology developed an ultralight bicycle that reminds on the first glance of the sports equipment of a bowman. “Only the top tube and the seat stays of the bicycle frame are firmly attached, the down tube and the chain stay are replaced by a tightly stretched rope”, explains Hendrik Berthel, who until recently studied Sports Engineering and further deepened this idea in his thesis. Together with the recent business engineer Sven Gläser and the Mechanical Engineering student Leon Kontny, he aims for the prompt revolutionization of bicycle frame construction with the so-called “bowbike” and capture the market.

“A bicycle frame of carbon is compared to aluminum and steel constructions light as a feather”, says Kontny. But the weight reduction has its price as a bike made of carbon is at least twice times expensive as an aluminum bike. This is due to two reasons: “Firstly, carbon fibers are much more expensive than aluminum, and secondly, components made of carbon are seldom possible to produce with a high degree of automation”, illustrates Kontny.

And right there the three-membered entrepreneurial team applies its bicycle frame concept “bowbike”: The only tensile forces absorbing components of the bicycle frame were replaced by a significantly lighter, rope-shaped medium. The hitherto hand-made glass fiber reinforced top tube of the frame will be manufactured with a novel cost-efficient technology in the future. “The acquisition of a pultrusion plant for the neighboring Fraunhofer Institute for Machine Tools and Forming Technology IWU gave the final impetus. The plant enables access to the pultrusion technology and thus the possibility to manufacture fiber-reinforced plastic profiles”, explains Berthel.

In the following two years the team wants to combine the bicycle frame concept with the pultrusion procedure and push their intention to establish a business forward. Aided by a EXIST Business Start-up Grant they want to manufacture a product in series production ready for sale and concurrently work on new developments. Scientific support offers Prof. Welf-Guntram Drossel, Chair of the Professorship of Adapatronics and Lightweight Design (in Production) at the Chemnitz University of Technology. Thomas Hipke, Head of Department Functionally-integrated Lightweight Structures at the Fraunhofer Institute IWU, is mentor in the field of construction, calculation, and pultrusion. Technical support for the team comes from Prof. Stephan Odenwald, Chair of the Professorship of Sports Equipment and Technology, at the Chemnitz University.

“Our main objective is to introduce a bicycle frame with an unbeatable price-performance ratio made of carbon fibers onto the market – made in Germany”, says Gläser. Bicycle dealers would benefit from it, too – the direct communication with the manufacturer, a short-term delivery, and high-quality standard just to name a few. “We could produce bicycle frames demand-driven and know from our previous market research activities that many bicycle dealers would prefer a production in Germany than in Asia”, adds Gläser.

The targeted market sector of the “bowbike” team are City-, trekking-, e-bikes, and children’s bikes. “The production of an ecological bicycle frame made of bio-fibers and bio-plastics is perspectively aimed for”, anticipates Berthel. Main target group are customers looking for an inexpensive and light bicycle with good design. “Many will be surprised about the look of our bowbike”, says Berthel.

The entrepreneurial project “bowbike” at the Chemnitz University is funded by the Federal Ministry for Economic Affairs and Energy and the European Social Fund (ESF) with approx. 118,000 euros from April 2017 till end of March 2018. The application took place through the entrepreneurial network SAXEED.

Further information on the project:

Contact: Sven Gläser, Hendrik Berthel and Leon Kontny, phone +49 371 5397 1233, email

Matthias Fejes

All "University News" articles

Press Articles