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.

News

Eurobike Show Daily 2011 - day 3
Reading time 5:20 minutes

Choice of the material – philosophy or technical reasons

Aluminium, carbon, steel or titanium, the discussions about the proper bicycle material are older than the beginning of the mountain bike boom and the triathlon hype that started in the middle of the eighties. Today, about 25 years after the comeback of the bicycle, every material has found its place and both wood and bamboo are experiencing a revival. An emotionally detached and therefore technically oriented guide through the often imaginative names and additional titles of the manufacturers.

Aluminium – the multi-purpose material

As early as in the thirties of the last century the first frames made of aluminium were made in France and Germany. The material that had been in the shadow of steel for many years, started its triumphal march when one succeeded in welding aluminium on a large scale and in manufacturing oversized tubes and thin wall thicknesses.

Pure aluminium as bicycle material would be completely unsuitable. It is only by the admixture of further metals, such as magnesium, titanium, zinc etc. in inferior percentages that readily processable and appropriate materials developed. The basic technical key figures of the tube sets remain mainly identical in spite of the alloy elements. Decisive for the question whether the frame is good or not is the constructive design of the frame, such as tube diameter, wall thicknesses, geometry, welds etc.

A miss is as good as a mile, in this case as well, as titanal is nothing but a highly alloyed aluminium with a high strength and poor weldability. This proved correct when frames made of lengthwise welded titanal tubes burst by the dozen.

You should therefore neither be impressed by the alloy descriptions, such as AL 6061, AL 7020 or AL 7005, nor by the trade marks, such as Kinesium, Ceramics or Scandium.

The facts

+ low density (1/3 from steel)

+ highly processable

+ ductile

+ allows many surface treatments

+ very good weldability according to the alloy

+ cost-effective

+ highly recyclable

- low elastic modulus (1/3 from steel)

- low strength

Status quo and potential

A reasonable bulk material that allows the production of bicycles from the city or trekking bike to the high-end downhiller. Due to the ductile properties, the material will maintain its place on the market, also in the field of sports bikes and in particular when it comes to the production of mountain bikes.

Carbon – top form in sports

In the middle of the eighties the first carbon tube frames rolled over French roads during the Tour de France. 1987 experienced the first entire monocoque frame and after 1992 it became relatively quiet with regard to the composite material composed of matrix, mostly epoxy resin, and the fibers, mainly carbon fibers.

In 2003 the first series-production frames at a weight of less than one kilogram was manufactured in Taiwan/China. This was the kick-off fort he the second wave of the carbon material. Contrary to all declarations stating otherwise, carbon frames do require the highest degree of manual work. Typically, the carbon fiber connection and orientation is made completely manually, the material is recreated with every component. Therefore, the basic material, i.e. the pure fiber grade, says absolutely nothing about the finished component. In theory, it is even possible that every component of a series has the most different properties, if the quality of the series production is not controlled and checked at one hundred percent.

The facts

+ very low density

+ very high elastic modulus realisable

+ very high strength realisable

+ nearly free design possible

+ corrosion-resistant

- non-ductile, breaks brittle

- sensitive to pressure

- difficulty in evaluating possible damage

- costly processing

- high priced

- durable surface coating difficult

- at present hardly recyclable

Status quo and potential

The material with still huge potential. Undoubtedly the number one when it comes to low weight, sophisticated design and highest strength. The anisotropic material properties provide an additional high frame stiffness when riding out of the saddle, act against wobbling and combine it with comfort. These properties are incompatible with all metallic materials. Limits are set by the professional and careful handling that is absolutely necessary with the partly extreme lightweight constructions and that not every customer is able to cope with.

Steel – the myth

First, it was wood that was used as material for the production of the draisine bicycle, then it was replaced by steel that was the number one material in bicycle production for more than one hundred years. In the beginning, enormous progress was made in the manufacture and processing, so that steel frames in the year 1935 already had conified tubes. After this period, however, the technical properties due to standardized tube and tube sleeve diameters remained nearly identic, i.e. until the middle of the eighties. In spite of focussing on true development, the tube and frame manufacturers concentrated on well-shaped craftsmanship, imaginative names and myth creation. With the appearance of aluminium, steel had hardly anything to add, despite a few tries. In the case of human-powered vehicles weight plays a major role and steel was quickly left behind.

The facts

+ high elastic modulus

+ high strength

+ highly ductile

+ highly processable

+ allows many surface treatments

+ very good weldability according to the alloy

+ cost-effective

+ highly recyclable

- high density

- oversizing only possible at limited degrees

Status quo and potential

Once it was the Rohloff hub, then the retro shaft for the singlespeeders and the cruisers that enchanted the fans of classical material and as a result provided both manufacturers and dealers with customers. Although exhausted in terms of engineering, steel tube sets are an option for small frame builders to manufacture individual frames in technical perfection for their customers by using a relatively moderate number of tools and with high manufacturing depth.

Titanium – pure material

Frames made of titanium have been built for decades and attract by a fine, but subtle appearance. In the beginning titanium frames were also praised for the inferior weight compared to steel frames, but the elastic modulus that is about half of that of steel frames put a spoke in the wheel. The classic titanium frame country USA are more and more overtaken by Russia and China. In particular, since the end of the cold war, Russian manufacturers of military devices have been looking for new uses for the titanium tubes.

The facts

+ high strength

+ corrosion-resistant

+ medium density (1/2 from steel)

+ ductile

+ resistant surface

+ highly weldable

- medium elastic modulus (1/2 from steel)

- oversizing only possible at limited degrees

- limited tube selection

- costly processing

- poorly durable coatings

- poorly recyclable

- highly priced

Status quo and potential

Due to the corrosion resistance and the high strength, titanium is predestined as frame material which does not need particular care and can be used throughout the whole year. It is the high material price, the costly processing and the relatively low elastic modulus which counteract a wider distribution. Therefore, titanium frames will have their place in the niche of those who are looking either for a corrosion-resistant frame or with a passion for the pure material surface and perfectly made welds on the precious metal.

Wood and bamboo – exotic material for the showcase race

Bicycle frames made of renewable raw materials have already been tested as early as at the beginning of bicycle development and are no invention of our current affluent society. With a modern design these bicycles not only have a fashionable and exciting appearance, but are also suitable for occasional rides. However, you shouldn’t have too high sporting ambitions as regards the suitability for daily use. As one the one hand some of the constructions are not competitive in terms of weight and on the other hand they possibly do not withstand high loads like the often used materials.

For this reason it wouldn’t be fair to compare the technical data.

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