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.


Soon, we will be able to move into our newly constructed building. Eleven month after the ground-breaking ceremony, the outer shell of the new company building was finished. Recently, this memorable moment was celebrated together with the craftsmen, staff members and business partners at a small topping-out ceremony. We are very happy about the fast progressing of the construction in spite of the hard winter so that we can move soon.

The additional space will be of good use for us: The current, rented company building in Ludwigsburg is bursting at the seams. We cannot wait to further develop at the new location which is in close vicinity. In the new functional rooms we will be able to maintain the usual high level of services for our customers and render them even more efficiently. Provided that the interior construction will progress as planned, we will be able to start moving in June. The company-own test laboratories and the offices will then be relocated step-by-step.

Pleasant reading wishes
Dirk Zedler

Topping-out ceremony

Faster results on components’ quality

Before moving into the new building already, Zedler-Institut extended their test laboratory. From now on our customers will benefit from additional testing systems for components and obtain the ordered test results as quickly as usual.

Not only frames, but also forks and add-on parts for bicycles and pedelecs must withstand the loads during the ride. To avoid material defects and defective constructions as well as expensive recall actions as a consequence thereof, more and more manufacturers also have components tested for fatigue strength and operational safety. Zedler-Institut responded to these needs by extending their company-own test laboratory. What's new is that eleven frames as well as forks, handlebars and seatposts are tested dynamically on two test stands respectively at the same time. For steerer tubes or handlebar/stem-combinations three test stands were set up side-by-side only recently.

Zedler-Institut does not only offer load tests complying with the currently applicable standards and ISO standards, but also extended test cycles upon request. These exceed the minimum requirements of the standards and realistically simulate the loads in service. In doing so each bicycle category is considered specifically. The bicycles and components are tested dynamically for fatigue strength, whereas the loads are adjusted to the forces of the respective categories realistically occurring in service.

Due to this increase in capacities we do provide our customers with the results at constantly high speed, regardless of the fact that the testing volume at Zedler-Institut has multiplied in many fields in the past months. It is a rule that each frame and each component is mounted on the first testing system 48 hours upon arrival at the test institute at the latest. After that the results can be made available within three to seven days depending on the test. This accelerates the processes in development and shortens the time to market of new developments.

Revised new edition of Zedler-Institut’s Basic user manuals

New developments in bicycle technology and new legal regulations regularly require revisions of the user manuals. Zedler-Institut grabbed the chance: together with the latest updates of their popular Basic user manuals in terms of contents the layout was redesigned.

Bicycle and pedelec manufacturers and importers who want to position themselves as customer-friendly suppliers and protect themselves against unjustified liability claims cannot do without practicable user manuals for their products. Manuals which meet these requirements must be precise, detailed, up-to-date, easy to understand and comply with the ISO/DIN standards.

Zedler-Institut has been elaborating such manuals for more than twenty years. The two most widespread two manuals were subject to a comprehensive update. The Basic manuals with brand neutral layout and contents as well as the Brand Basic manuals with customer-specific cover were brought up-to-date in terms of bicycle terminology. The road bike version, for example, was complemented with thru-axle instructions. The mountain bike manual was updated with a new chapter on the adjustment, use and maintenance of vario seatposts. The EPAC manuals were completed with information on new drive systems. In addition, all contents were updated legally in consideration of legislative changes for bicycles and pedelecs in countries, such as Germany, France, Switzerland, the Netherlands, Italy, Spain or Great Britain.

Legal certainty by means of confirmed quality
“Our manuals meet all necessary requirements and release our customers from liability in legal issues”, says Petra Grunewald, Head of Technical Documentation at Zeder-Institut. The bicycle experts from the Ludwigsburg, Southern Germany, know what they are talking about, because their manuals have repeatedly been tested and approved by the authorities when customers were in critical situations. With the help of the carefully compiled contents it has already been possible to prevent officially threatened sales bans in several cases.

The value in use of the Zedler manuals was repeatedly pointed out by independent bodies, such as the German foundation for comparative product testing (Stiwa). In comparative tests of the consumer protection organisation they have come out as winner already several times. Many bicycle suppliers trust in this quality. In the past years the Basic and Brand Basic manuals were printed for more than 100 customers with a total print run of more than one million copies.

Small quantities, fast availability
In order to be able to serve customers in line with demand, Zedler-Institut deliver the Basic user manual in six languages starting from quantities of 50 pieces. All versions for mountain bikes, city/trekking bikes, kids’ bikes, BMX bikes and road racing bikes as well as the supplementary instructions for pedelecs/e-bikes are available in Germany ex warehouse within about four working days. Brand Basic manuals with an individualized cover from our German print shop or from our production partners in Taiwan can be shipped upon approval by the customer to a desired destination within about four working weeks.

Pedelec and the law: two lectures at the Eurobike Show

The pedelec set the cycle industry in motion, it entails, however, additional challenges in terms of legislation, too. These will remain in the industry, like the pedelec itself. Therefore, it is already worth noting two lectures at this year’s Eurobike Show: Dirk Zedler will speak about modifications as a result of applicable law relating to the pedelec from the view of the manufacturers and the dealers.

Addressing the cycle industry, graduate engineer Dirk Zedler presents the technical challenges that pedelecs must fulfil in accordance with legislation, EN/ISO standards and court decisions in the European Union. In addition, he will explain why pedelecs should be tested under test requirements going beyond the EN/ISO standards.

He will advise manufacturers and dealers on how to prevent lawsuits with disappointed customers. From his experience as publicly appointed and sworn-in bicycle expert he will show ways of how to harmonize processes in companies with applicable legislation and standards.

The lecture addressing the cycle industry will be held in English, the other one addressing manufacturers and dealers in German language. Both seminars will last 45 minutes and take place during one of the business days at the 2017 Eurobike Show. Detailed information on the precise date and the conditions of participation will be published online in the following weeks at

The press about us or "do good and let the others report about it"


Dirk Zedler - Pedelec Akku-Check

The 2016 market statistics of the German bicycle association ZIV most recently confirmed, what every bicycle manufacturer and retailer have probably already realized in his daily routine: The pedelec has actually arrived at the centre of society. More and more people use the electric bicycle, and these are by far not only “best agers”.

The new consumer groups and new fields of use come along with new demands what pedelecs can and should be able to bear. We have been thinking about these requirements on the cycle industry and we would like to share these thoughts with you.

Inspiring and pleasant reading wishes

Dirk Zedler

A weighty challenge

E-mountain bikes are enjoying increasing popularity. According to the latest market figures released by the German bicycle association ZIV, more than one in seven of the 605,000 pedelecs already sold in Germany are eMTBs. To ensure a long-term success for manufacturers and dealers you should be aware of the additional challenges with regard to product liability and fatigue strength this young product group entails.

As there is currently no specific testing standard for e-mountain bikes in force, the models are often tested in accordance with the EPAC standard EN 15194. This standard is, however, made for designs and loads typical for city and trekking bikes. Experience that is meanwhile acknowledged in the industry shows, though, that even the forces on motorless bicycles are significantly higher on sporty off-road rides than those arising in everyday mobility. This fact is accounted for by the ISO standard 4210 for mountain bikes.

Therefore, this standard is sometimes used as reference value for the fatigue strength and the operational safety of e-mountain bikes. It is closer to the loads arising in riding practice. It is, however, not able to depict these in full. On the one hand this is due to the fact that these bicycles are clearly faster uphill as an auxiliary motor allows for more powerful acceleration. This increases the forces acting on the frame and on some components of e-mountain bikes compared to those motorless models are exposed to. On the other hand cross-country bicycles with auxiliary drive are currently about 8 to 10 kilograms heavier than usual mountain bikes which is another reason why the frame is exposed to higher loads.

The standard currently does not include a hard limit, the implicitly given limit of the total weight being, however, around 100 kilograms. The limit is easily exceeded, a fact made clear by a simple calculation: According to the manufacturer’s indication, the weight of an average electric hardtail is mainly above 19 kg in model year 2017. Adding a packed rucksack with carefully calculated 6 kg, the rider’s weight including personal equipment (clothing, shoes, helmet) must not exceed 75 kg. According to the official statistics, the German average man, however weighs 84.3 kg (source: For him, the safety reserves of the mountain bike standard are definitely not sufficient, if he sits on a customary ISO tested electric mountain bike.

In order to account for the loads arising during the ride, Zedler-Institut developed SAFETY tests for bicycles and pedelecs which are based on the ISO standard, but subsequently go beyond these requirements. Frames and components do not only undergo tests with higher loads, but also tests which are not included in the standard. According to our experience and the customer service departments of our clients, the bicycles can be approved for higher weights of 120 or 140 kg with a clearly reduced failure rate.

These types of tests and load levels were developed on the basis of our experiences from our activity as bicycle experts writing expert reports about material failure during the ride. The operational safety of all products that pass these strict requirements will in addition be awarded with the Advanced or Advanced Plus seal of Zedler-Institut. In general, SAFETY tests will be performed in the laboratory of Zedler-Institut within three to ten working days.

Any difference between English and English?

British and US cyclists do not speak the same language: Especially in terms of technical terms, spelling and units of measurement there are significant differences between the English languages of both countries. Bicycle manufacturers committed to customer satisfaction in the respective markets supply their customers with user manuals which are adjusted to the respective language.

In many cases there are minor differences between British and American English. Sometimes, the differences come as varying spelling (e.g. tire / tyre, aluminium / aluminum, fiber / fibre, derailleur / derailer) and sometimes the different technical terms need a context to be identified correctly (e.g. puncture / flat). There are, however, some bicycle components, for which the British and Americans use completely different terms (e.g. mudguard / fender, luggage / baggage etc.). To avoid any misunderstandings before your customer sets off on his or her bike for the first time, the terms in the user manuals should be adapted to the country-specific requirements.

But still more important are the respective units of measurements used in the user manual of a bicycle. With regard to virtually all measures which are important for the individual adjustment of a bicycle to its user, Englishmen and Americans use different units, such as for example cm / inches for the lengths, kg / lb for the weights, bar / psi for the air pressures and °C / °F for the temperatures. The average cyclist is not used to converting the units, as a consequence of which the risk of error is comparably high. But once riding fun or operational safety depends on the correct adjustment (e.g. air pressure of suspension elements or tyres), a bicycle manufacturer with customer satisfaction in mind should avoid any misunderstandings and conversion errors by using the respectively familiar units in the user manuals.

The team of Zedler-Institut has many years of experience in the production of user manuals for the American and the British market. Linguistic differences are therefore taken into account when developing customer-specific premium manuals. Upon request we are also able to adapt existing user manuals from the British to the American version at a small extra fee. Bicycle manufacturers considering the country-specific differences between the USA and England signal their particular appreciation for their customers in these countries.

"Triceratops" for Munich

Whoever wants to perform objective tests, needs suitable test devices. This is the reason why Zedler-Institut updated and extended the laboratory of the leading German special-interest magazine bike – Das Mountainbike Magazin in the past months.

In its internal laboratory, bike has been performing tests for years to discover incorrect statements of manufacturers and to confirm findings of field tests. The editorial team of Europe’s biggest special-interest mountain bike magazine mainly relies on test stands made by Zedler-Institut. In the past months the bike laboratory was brought to the state-of-the-art with a newly developed testing system to record the relevant frame data of a mountain bike and a wheel testing system.

These testing systems are appreciated a lot by the editorial team; that’s why one of the delivered new test stands was affectionately nicknamed "triceratops" after a few weeks only. This nickname refers to the three functions for the measurement of the central frame stiffness, the spring characteristic curve of fork and rear frame as well as to the wheel trajectory curve.

The way tests are performed by the editorial testing team was videotaped. See the video by clicking the following link:

Identical testing systems are available at the Zedler-Institut laboratory and may accompany your new developments. This means, the innovative recording of relevant data can improve your products prior to their market launch already.

Upcoming event: young meets old

To celebrate the bicycle’s 200th birthday, pupils designed an exhibition on the history and development of the bicycle. Zedler-Institut actively supported them during preparation. The results of this cooperation will be shown in the following months at the State Archives Ludwigsburg.

The seminar course of Technisches Gymnasium Umwelttechnik of Ludwigsburg’s Oscar-Walcker school had been exploring the development of the bicycle from its beginning on during the past months. The results of these inquiries were comprised in an exhibition that will be open to the public from March 22 to June 29, 2017 at the State Archives Ludwigsburg.

Each pupil focused on an outstanding bicycle from the past 200 years, which will be documented in the exhibition about the development from Draiss’ velocipede to today’s bicycle. The exhibition does not only show the technical developments, but also the bicycle’s impacts on mobility, culture and society.

Zedler-Institut helped the pupils to work their way through history and development of the bicycle. A few bicycles displayed originate from the collection built up by Dirk Zedler together with the Ludwigsburg bicycle enthusiast Helge Schultz. For their project the pupils obtained the necessary technical information, historical background knowledge and extensive photographic material.

Some of the bicycles described will be shown as a loan during the exhibition at the State Archives Ludwigsburg. Besides the historical exhibits Zedler-Group contributes to the exhibition numerous active elements by means of which the interested public may experience directly the progress in bicycle technology. This includes samples of various components, such as wheels or frame tubes. By touching and lifting these parts visitors may experience the differences in weight and comfort between former designs and state-of-the-art designs. On two cycle trainer rollers visitors of the exhibition have the opportunity to cycle on two considerably different bicycles.

The exhibition’s opening hours are from Monday to Thursday, 9.00 a.m. to 4.30 p.m., and on Friday, 9.00 a.m. to 3.30 p.m. In addition, the exhibition is open on Saturday, April 29, 2017 from 11.00 a.m. to 5.00 p.m. as well as on the following Sundays April 9, May 7 and June 11, 2017 from 2.00 p.m. to 5.00 p.m. The entry is free. More information and details on booking a tour through the exhibition are available at the State Archives’ website.

51,000 kilometres or 31,700 miles

The team members of Zedler-Group do not only deal with bicycle theory. In fact, they use their bikes for commuting every day - even at sub-zero temperatures. All kilometres taken together, they ride once around the world every year.

For many of the employees working at Zedler-Group offers the opportunity to combine personal passion with professional commitment. The fact that they use their bicycles for commuting regularly, hereby covering considerable distances, is therefore not astonishing. A current count revealed that the 22 employees cover a distance of altogether 51,000 kilometres / 31,700 miles by commuting. This is once around the world. The daily distances range from a few hundred metres to up to 50 kilometres / 31 miles. This means all in all about 230 kilometres / 140 miles ridden on average per working day.

This does not only keep the Zedler team fit and healthy, they also gather valuable practical experience on how bicycles and individual components prove in real conditions. Therefore, various test bicycles and pedelecs for commuting are made available to them by their employer. In return, the employees document distances, irregularities, wear and tear and in the case of pedelecs each battery charging. The results of a five-year study on wear and tear was published for example as largely noted report in the German special-interest magazine Trekkingbike. These bicycles are regularly serviced in the company’s own workshop to ensure that they are safe and reliable at any time.

As environmentally conscious company, Zedler-Group support their employees a lot when it comes to commuting by bike. There is for example a large, weather-proofed bicycle parking close to the company’s main entrance. Locks are available for free use. There are clean shower facilities and regularly washed towels available inside the building. Everyone has a locker and access to drying rooms for his/her cycle clothing and personal stuff.



Dirk Zedler - Pedelec Akku-Check

Shortly after the press had reported about the battery fire in an e-bike shop in Hanover, Germany, numerous enquiries about the incident of worried pedelec owners and employees of the cycle industry started piling up at Zedler-Institut. The battery of an electric bike had allegedly caught fire after charging and caused a major fire with high damage to property. The fire had not yet been fully extinguished when the safety of pedelec batteries was questioned in general by the first media reports and comment columns already.

With regard to this excitement I ask for patience in this matter: Blanket speculations on the safety of pedelec batteries as a consequence of this event of loss alone are not reasonable. We know that various reputed battery manufacturers use every technology available to successfully prevent their products from malfunction.

On the other hand, we found that the shop in question offers complete vehicles, conversion kits, batteries from little known suppliers as well as tuning kits on their website. With some of these products the statutory reference values for the legal operation of pedelecs and further vehicles on public roads are most probably ignored. This raises doubts as to the safety awareness of the e-bike shop. Final statements cannot be given until the official findings as to investigations of the causes of fire will be available.

Warm regards and good thoughts wishes
Dirk Zedler

Making the sector "battery-proof"

Those who want to deal seriously with objective information on development, sale and safe use of pedelec batteries, regardless of the current event of loss, are recommended to attend a seminar of Battery University in Karlstein on Main, Germany. There are still free places available for all interested parties.

Various lecturers in the fields of research, production and testing will provide among other things an overview of the basics of battery construction, the current state of the art and legal framework conditions (CE marking, transport regulations, product liability etc.). Dirk Zedler will give a lecture on bicycle testing and expert reports, product safety and the legal situation. Short-term registrations are still accepted directly at Battery University.

Real loads in the laboratory

Prüfmethoden für Hinterbauten von Mountainbikes

In the past years various bicycle manufacturers had to learn the hard way that tests passed in accordance with ISO standards are no guarantee for a reliable, safe function of bicycles and components. To avoid expensive liability claims or civil actions as well as costly recall actions it is worth performing load tests going beyond the standards prior to the market launch. For this purpose Zedler-Institut developed additional test methods for the rear triangles of mountain bikes.

In addition to the ISO standard and Zedler-Institut Advanced Plus, frame fatigue is tested first by applying recurrent vertical loads to the rear triangle. Subsequently, concentrated load peaks are simulated. The frame is tested intensively to its capability of withstanding terrain-induced effects and heavy impacts (e.g. In the case of jumps, drops).

In their completeness the tests not only meet the Zedler-Institut standards, but also the ISO standards currently in force. They also comply with the state of the art required by the product liability law. Test seals on Advanced Plus level developed by Zedler-Institut can be ordered optionally by frame and fork manufacturers, together with the basic ISO tests.


Batteries in use

Akkus in der Anwendung

The reliable safety of a pedelec battery depends only in parts on its construction. The way it is handled by its owner is at least equally important. A customer-oriented user manual can prevent fears and faults in battery handling.

The strongest and safest battery cannot develop its full potential when not used as specified by the manufacturer. We know from our expert practice that negligence and a too careless handling of the power storages are frequently the reason why batteries get broken.

Such kind of damage can be prevented, if the pedelec owner is instructed in readily comprehensible language how to make the best of a battery. "Our completely documented manuals explain to the reader step-by-step how to charge and store the battery of an e-bike, what things he is allowed to do and what he should prevent," says Petra Grunewald, Head of the Technical Documentation department of Zedler-Institut. "Such kind of clear information establishes clarity for the customer and confidence into the product. This increases the riding fun in the long run and hence the customer’s satisfaction with his pedelec."

Exact and comprehensible instructions for an appropriate handling of batteries are already part of our Basic user manuals which are immediately available ex store in six languages. The individualised user manuals "Brand Basic", "Individual" and "Premium" can be provided with additional information and pictures tailored to a manufacturer or a certain pedelec model.

Politics at the test laboratory

Politik im Prüfinstitut

The fact that bicycles play an increasingly important role not only in the field of mobility, but also in Germany’s economy, is more and more perceived by politicians as well. The visit of Matthias Gastel, member of the German parliament, at Zedler-Institut is just one example for this.

The member of the Committee of transport and digital infrastructure used the visit to get our test laboratory and the development of expert reports and user manuals explained. Gastel seemed to be impressed by the high level of testing technology in the cycle industry as well as by the way Zedler-Institut managed to increase their economic success in the past years which in his eyes was not easy. Matthias Gastel praised the company’s innovative power and certified Dirk Zedler and his team a high motivation to promote the "good" bicycle.

200 kilograms of novelties

The market archive of Zedler-Group is constantly growing: Since 2016 Eurobike Show our employees have collected and catalogued several hundreds of sales brochures and technical manuals of bicycles, pedelecs, components and accessories. This helps us providing you with information on what is sold today at a later date.

When it comes to determine the age and the value of a bicycle, the Zedler-Group market archive renders indispensable services for the development of expert reports. Every year they spend several working days on completing the archive with the latest product documents of several hundreds of manufacturers to enable the experts of GDFS to continue their work over the long term.

For this purpose the GDFS team systematically visited the more than 1,000 exhibitors on two days of the past Eurobike Show and collected catalogues and price lists of the 2017 model year from their booths. During these two days the six employees collected catalogues with a total weight of about 200 kilograms. Since the Show these product documentations have been registered in the content overview of the market archive and filed in a way that they are available without searching, if needed. In addition to the printed catalogues, the GDFS team also stores the offers made available by brand manufacturers, mail-order companies, department stores and DIY-stores in digital form. This is necessary for a comprehensive market overview, because many brands display their bicycle models on their websites only and often this information is not available for download over the long term.

At present the Zedler-Group market archive comprises already more than 15,000 catalogues and technical user manuals of bicycle brands and component manufacturers that have been active on the German market over the past 30 years.

The press about us or "do good and let the others report about it"

SAZBike - Akku-Explosion Dirk Zedler