All about bicycles, electric-assisted bikes, technology and safety in the press

The most common safety risks that we come across in our daily work around bicycle safety, technology and operating instructions are also published by us in articles in the leading German special-interest magazines TOUR (Europe's road bike magazine no. 1), BIKE (Europe's mountain bike magazine no. 1), MYBIKE and EMTB in order to make this information, which is important for the industry, available to a wider public.

For many years now, the Eurobike Show Daily, trade fair magazine of the annual Eurobike Show, has also given us the opportunity to publish our view of major developments in the cycle industry in full-page articles.

We also speak regularly in independent expert presentations about all areas of bicycle technology and the bicycle market. In addition, we are quoted by further special-interest magazines of the industry and the trade as well as increasingly by radio and television in their media reports, which shows us that we are spot on with our advice. The section "News" informs you about the latest news from our specialist areas. The reports and publications of this section are listed chronologically or according to areas of interest.

RadMarkt 02/2010
Reading time 2:30 minutes

Carbon – The Golden Calf

On November 12/13, 2009 the German Association for Materials Research and Testing (DVM) held a workshop in Berlin in cooperation with DIN, the German Institute for Standardization. Title: Test procedures and quality assurance methodes in consideration of CRP materials.

Twelve months ago the German Association for Materials Research and Testing (DVM) had held a first workshop on “Service strength in bicycle construction” in cooperation with DIN, the German Institute for Standardization. The feedback had been positive enough to organise a follow-up workshop. It had was managed by the meanwhile founded working team “bicycle safety” with Dr. Eric Groß of Technische Universität Hamburg-Harburg, Siegfried Neuberger of the German two-wheel-industry association and the bicycle expert Dirk Zedler of lngenieur- und Sachverständigenbüro Zedler, as members.

The workshop offered a wide range of issues. The contributors were experts, mainly from research and industry. 53 percent of the 70 attendees came from the industry, one from the aircraft manufacturer Airbus, 27 percent from universities or institutes and 10 percent registered as experts. No more than one percent of the attendees was from the trade sector, the other attendees being classified as ”miscellaneous“. From this partitioning one could already expect high-quality speaches.

Carbon Findings

Some of the contributors started by explaining the structure of carbon materials: Besides die cast components with short carbon fibres, it is primarily the fibre composite components with long fibres that are well known. The finished components are made with a more or less high share of handicraft of fibres and the matrix as thermoset material.

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From this material structure one can draw two conclusions: First, it can be stated that not all components are equally suitable for being used for construction with carbon fibre material. Structures that can induce load cases on large component surfaces are particulary suitable. The extremely high fatigue strength allows very high numbers of load cycles.

Secondly, there is no such thing as ”the“ component, as due to the wide spread usage on the models the components handcrafted to a large extent are actually individual items.

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Dirk Zedler, Ingenieur- und Sachverständigenbüro für Fahrradtechnik, Ludwigsburg: “Many problems with bicycle components made of CRP arise from false expectations of the customers and a lack of knowledge of the mechanics in the cycle shop. Continuing training for dealers and mechanics are absolutely necessary; the specialised press is in charge of delivering profound and realistic reports and the final customer must be provided with clear instructions when he obtains his product.”

Conclusion

Carbon differs from other materials used for the construction of bicycle frames or components. This must be taken into account during construction as well as during manufacture and quality control including the extensive tests and test procedures. The special characteristics of the composite materials must, however, be considered to some extent by the standards, as well. The first steps in this direction have already been made: On the occasion of the meeting of the CEN TC-333 (Technical Committee for Cycles) in September 2009 it was stated that special attention should be drawn to composite materials, even with regard to the standards already in force. But the experts of the sector have already been sensibilised by the DVM workshop. This pushes a lot the issue of carbon as construction material in the cycle construction as well as bicycle safety in general.

Author: Jörg Kreinjobst

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