Machines putting bikes through their paces

The Zedler-Institut in Ludwigsburg, Germany, tests bicycle components and prototypes and develops testing machines that are used worldwide in the labs of major bicycle brands. When designing bicycle test systems, Zedler's engineers rely on standard and operating parts from norelem.

Zedler - Institut für Fahrradtechnik und -Sicherheit GmbH, based in Ludwigsburg, Germany, is part of the Zedler Group and has specialised in the development and construction of testing systems for bicycles and e-bikes since 1994. In the company's own test laboratory, bicycles and components such as frames, handlebars, saddles and baggage racks are tested for operational stability - both on behalf of manufacturers and dealers when testing prototypes and for insurance and courts as part of expert reports in the event of accidents or damage.

As well as carrying out tests, the company develops and produces its own testing machines, which are used worldwide in the test labs of leading bicycle manufacturers. The institute also produces standard compliant operating instructions and manuals for bicycles and e-bikes. With four dynamic laboratories and around 50 fatigue testing systems together with a consistently sustainable corporate orientation, Zedler GmbH is today a globally recognised partner for quality and safety in bicycle technology. "We are a classic hidden champion for customers from all over the world, although we are primarily known in the bicycle industry," says Dirk Zedler, founder, test specialist and expert at the Zedler-Institut.

Bicycles and pedelecs are in motion, often daily and over alternating surfaces. Bicycle frames range from very compact folding bikes with small 16-inch wheels to cargo bikes with a wheelbase of up to 2.15 metres and different size wheels front and rear to tandems for two cyclists. In addition:°

• City bikes often have a deep peddle position so that cyclists can comfortably put their feet on the ground when stopping at traffic lights.
• Mountain bikes (e.g. Enduro), on the other hand, need a lot of ground clearance so that the pedals do not scrape on the floor so easily when off-road, even by compressed suspension.

Versatile, adjustable and always resilient

In order to accurately reproduce different geometries, wheelbases and pedal heights, test systems must be highly adjustable and simultaneously very rigid and resilient, as they have to be able to transfer precise forces to a wide variety of bicycle frames over many years.

To ensure that a frame can withstand these permanent loads over many years, there is a classic test in bicycle technology: the bottom bracket fatigue (BBF) or pedal bearing position fatigue test. The bottom bracket is one of the most stressed areas on a bike frame and the point at which the pedals are connected to the frame via the pedal cranks. Each rotation generates alternating torques, bending and torsional forces that accumulate over a long period of time. Without sufficient stability, cracks could form, eventually leading to fractures or failures.

Simulating pedalling forces

In their test laboratory, Zedler simulates the forces that a person generates when pedalling, the so-called "pedalling forces". A bicycle frame with built-in bottom bracket is repeatedly subjected to artificial loads. This enables the determination of how many load changes (cycles) it can withstand before the first signs of damage such as hairline cracks, cracking or play in the bearing appear. The BBF system developed by Zedler is characterised by its special adaptability to different types of bicycles and its durable design. As soon as all parameters have been adjusted, the test system reproduces the pedalling load that a cyclist applies to the frame over the course of the bicycle's life, within ca. 24 hours.

The institute works exclusively with test systems developed in-house, such as the performance testing machines. They measure the cycling characteristics and also the properties of individual components and deliver reliable results on cycling stability, cycling safety and comfort under comparable conditions. Statements can also be made about the consistently high quality of a production batch.

Inspiring product portfolio

When building testing machines, Zedler does not rely solely on its in-house expertise, but also relies on partners such as norelem and their extensive portfolio of standard and operating parts for machine and plant construction, or in other words: Here you will find a lot of ideas and solutions that inspire Zedler time and again.