Press release
September 3, 2009

CFRP Racing Bike Wheels with ROHACELL® from Evonik

These days, some of the world’s premium racing bike wheels have rims made of carbon fiber-reinforced plastic (CFRP) and a special ROHACELL® foam core, that is a polymethacrylimide rigid foam manufactured by Essen, Germany-based Evonik Industries. Because it is not only extremely rigid and solid, but also possesses very low density, ROHACELL® is an ideal material for lightweight, yet durable sandwich components.

ROHACELL® has particularly high thermal stability and compressive creep resistance; and it can be durably combined with all conventional plastics by applying heat (up to 190°C) and pressure (up to 7 bar) to manufacture extremely robust composite materials. Together with the rim’s CFRP shell, this results in a high-strength rigid, minimum-weight structure: The front and rear wheels together weigh less than a kilogram. Thanks to the remarkable characteristics of the material, the wheels are both light and aerodynamic and highly rigid. As a result, only a small fraction of the rider’s pedal power distorts the wheels and is thus lost; most of it is transmitted efficiently to the road surface. More details about this and other ROHACELL® applications are available at Evonik's Booth, F12 in Hall 4, at the Composite Europe.

Dr. M. Alexander Roth
Head of New Technologies - ROHACELL®
Performance Polymers
Evonik Röhm GmbH
64293 Darmstadt

About Evonik

Evonik Industries is the creative industrial group from Germany which operates in three business areas: Chemicals, Energy and Real Estate. Evonik is a global leader in specialty chemicals, an expert in power generation from hard coal and renewable energies, and one of the largest private residential real estate companies in Germany. Our strengths are creativity, specialization, continuous self-renewal, and reliability. Evonik is active in over 100 countries around the world. In its fiscal year 2008 about 41,000 employees generated sales of about €15.9 billion and an operating profit (EBITDA) of about €2.2 billion.


In so far as forecasts or expectations are expressed in this press release or where our statements concern the future, these forecasts, expectations or statements may involve known or unknown risks and uncertainties. Actual results or developments may vary, depending on changes in the operating environment. Neither Evonik Industries AG nor its group companies assume an obligation to update the forecasts, expectations or statements contained in this release.