Dirk Zedler is founder and managing director of Zedler-Institut (Ludwigsburg) which now also has a test laboratory exclusively for cargo bikes. According to Zedler’s own statement, he advises and supports a relevant proportion of the cargo bikes sold in Europe and has accompanied several market surveillance procedures and recalls involving cargo bikes. In addition, he is actively involved together with a colleague in Zukunft Fahrrad’s transportation work group. On the occasion of the current discussion about the safety of cargo bikes, he answers the questions related to safety.
SAZbike: “Hello Mr Zedler, is there a design-related safety problem with cargo bikes?”
Dirk Zedler: “Yes and no. There are very committed manufacturers on the market who develop these types of bikes adequately, have them tested and monitor the quality in production. Their durability and safety level is exorbitantly high and exceeds by far the minimum safety required by the standard. And then there are manufacturers who don't care a lot, produce mediocre quality and make them available on the market at very favourable prices.”
SAZbike: “Are certain designs more susceptible than others?”
Zedler: “In principle, redundancy is a magic word in design, but that is what is lacking. With only one frame tube running from front to back that is then supposed to carry 200 kilograms or more, the risk of failure and a fall as a result is significantly greater compared to a multi-tube design. If one tube fails and I have another one that can take over at least part of the function, I still have the chance to stop if it fails. Of course, you can also build single-tube design safely, but that requires a lot of effort and then the supposed price advantage is gone.”
SAZbike: “What part does the behaviour of cargo bike users play in accidents?”
Zedler: Personally, I think it's missing the point to blame the users for ‘overloading’. It is up to a manufacturer to define a use in a meaningful way. If two seats are provided for children, it can be assumed that some luggage will also be transported, e.g. lunch bags and drinking bottles for daycare or school, office bag with laptop for the adult if necessary. If you then know that the average man in the D-A-CH region weighs just under 90 kilograms, it's easy to do the maths. It seems absurd to me to set a permissible total weight below this.
A point that some users can be blamed for is that they stop by their dealers too seldom to have their transportation bikes serviced. We still need to work on the ‘culture’ in this regard. That's why I think the maintenance contracts that are part of some leasing agreements make a lot of sense.”
SAZbike: “How can the specialist trade make cargo bike traffic safer?”
Zedler: “Now that the weaknesses of some very low-priced suppliers have become public, even the last dealer should have realised that good cargo bikes have to come at a price. This must be included in the advice given, as well as the fact that transportation bikes are technical devices for which thorough checks and maintenance are essential. The current situation offers the best opportunity to position yourself as a good retailer with reputable brands. At the other end in purchasing, I consider it legitimate for retailers to ask how and where cargo bikes have been tested. In our experience, tests outside the EU are unfortunately all too often not worth the paper they are printed on.”
SAZbike: “Thanks a lot for the interview, Mr Zedler.”
The interview was conducted by: Tillman Lambert
Photo: Zedler-Institut