For the Joy of a Comfortable Ride

There are many bicycle trailers on the market. But how do you make their safety and riding comfort truly unique? The answers come from Projekthaus aidoo e.k. in Seelbach near Lahr in the Black Forest. This specialist in bicycle trailers has built a strong reputation since 2012. This reputation is also based on the company’s strong emphasis on material selection and the fact that nearly all components are manufactured in Germany—as exemplified by the oil brakes from Hahn Gasfedern GmbH.

Reconciling individual mobility with environmentally responsible behavior is a guiding principle behind the company and the eponymous aidoo brand. Founded by the married couple Pascale and Turan Dardagan, the company develops, manufactures, and markets innovative, sustainable mobility and transport solutions centered on bicycle trailers. The solutions—which, among other accolades, won the Brandnew Finalist Award in the e-bike category at the 2013 ISPO sports trade show in Munich—are extremely versatile and accommodate payloads ranging from 40 kg to 100 kg.

Wanted: A compact suspension solution without spring tips

In an interview, inventor, developer, and designer Turan Dardagan describes aidoo’s customers as second-time trailer buyers who were dissatisfied with the ride quality of their first purchase. He briefly notes that he himself belonged to this target group before launching aidoo and explains: “Standard bicycle trailers either have no suspension at all, use elastomers that tend to harden over time, or are equipped with leaf springs. If telescopic springs are used, there’s always a breakaway torque, and what we really want is to dampen the small vibrations on the road—which is exactly what the rubber torsion spring does.” The expert quickly realized during his early modifications of trailers that while rubber generally provides good suspension—and rubber torsion springs in particular can be maintenance-free and durable products that even compensate for the additional installation of bearings—he elaborates: “However, rubber only provides limited damping and can contribute to the chassis rocking back and forth. So we needed something to smooth out the peaks and troughs of the rubber. We initially experimented with products from suppliers of mountain bike shock absorbers. However, these took up too much space in terms of installation dimensions, and they also provided too much damping because they were always designed for only one wheel—namely, the rear wheel.” Since aidoo trailers were designed with two wheels from the start, the research continued until a local auto parts store gave him an important tip during the prototyping phase in 2012.

Found: A Partner for Custom Oil Brakes

The automotive specialists recommended considering industrial gas springs and oil brakes for integration into aidoo’s unique independent suspension system. For Managing Director Pascale Dardagan, contacting HAHN Gasfedern GmbH in Aichwald near Stuttgart was a natural choice—and not just for geographical reasons. This expert brand, which has been part of the Stabilus Group since 2016, ranks among the industry’s leading companies thanks to its uncompromising quality, innovative products, and absolute customer focus. The specialist in gas springs, gas-tension springs, and dampers has consistently reaffirmed this position since the 1960s with a highly qualified team that now numbers over 250 employees, serving companies of all sizes worldwide with proven experience and expertise as well as state-of-the-art machinery. The fact that HAHN’s particular strength lies in the development of customer-specific solutions is also illustrated by the ongoing collaboration with aidoo.

When asked about her experience with HAHN, Pascale Dardagan points to a shared learning process and says: “If volume is the top priority, innovation cannot go into series production. As soon as an industrial company understands this, new business opportunities arise for both sides.” In the case of the relationship between a manufacturer like Projekthaus aidoo and HAHN Gasfedern GmbH—a subsidiary of Stabilus, the global market leader in gas springs— the business partners agreed to offer the oil dampers no longer exclusively as accessories, but as standard components of aidoo bicycle trailers. This allowed production volumes and prices to be integrated into a coherent overall concept for a small-batch production run, which also includes the machine-applied aidoo logo on each individual damper.

When asked how HAHN was also able to impress from a technical standpoint, Turan Dardagan replied: “This series can be customized to the customer’s specifications in terms of pistons and housings, so it could be integrated into the aidoo independent suspension system without having to modify existing design drawings. The series can be used for different damping rates by adjusting the nozzle bore. For example, with aidoo, you can choose between payloads of 40 kg to 100 kg and get the right oil dampers for every mass being carried. To the best of my knowledge, no other bicycle trailer offers this feature. And when you ride an aidoo for the first time, you don’t even notice that you’re pulling something behind you. The ride feels more like driving a car: no jolts, constant contact with the ground, no bouncing of the suspension, and higher speeds are possible while maintaining greater safety. This makes our customers 100 percent satisfied, especially when transporting dogs or delicate goods such as electronics or glass bottles."

Planned: Oil brakes for bicycle campers and swing-arm axles

Design engineer Dardagan highlights the fact that HAHN’s oil dampers are also available in stainless steel versions—optionally with V2A or V4A alloys—as an additional advantage. When asked about further potential for optimization and growth, he responds that such potential always exists and explains: “We currently offer a custom axle design for bicycle campers that combines all the advantages of the aidoo suspension system and allows campers to design their own bodywork to fit it. The delivery of the components for this can still be optimized to offer a wide variety of mounting options for customer-specific superstructures. For example, oil dampers with adjustable compression and rebound settings would be useful here. We can test this out in the future together with HAHN. We’re also currently discussing the topic of swing-arm axles internally.”

One thing is certain regarding these innovations: Regardless of which ones Projekthaus aidoo e.k. from Seelbach near Lahr in the Black Forest implements in the future, the recipe for success—the leak-free quick-release coupling, which allows an aidoo bicycle trailer to be attached to and detached from the towing vehicle in seconds—will continue to be a key feature. And we can also look forward to the further integration of custom-tailored braking and damping solutions from HAHN Gasfedern GmbH in Aichwald, Baden-Württemberg.

Expertly designed: Fixed and adjustable components that fit

Oil brakes from HAHN Gasfedern GmbH are sealed, maintenance-free hydraulic components. In addition to bicycle trailers, these are primarily used for the smooth deceleration of feed mechanisms, linear drive units, flaps, and in other designs. These easily integrable braking components ensure—not only in boat and vehicle manufacturing or the furniture industry—that moving masses do not exceed a predefined speed. This achieves uniform damping over the entire range of motion, precisely coordinated with the object being moved. This results in numerous advantages, such as increased safety, greater comfort, reduced maintenance requirements, and longer service life.

The fixed-setting HAHN oil brakes operate in the tension or compression direction—or in both directions—with braking forces ranging from 5 N to 2,500 N, depending on the model. For applications where the forces are unknown or are intended to vary, adjustable HAHN oil brakes are available, whose damping force can be increased or decreased by rotating the piston rod.

Upon request, HAHN also designs, develops, and manufactures oil brakes to meet individual requirements and supplies these custom models—as well as the standard types—in either steel or stainless steel, in the V2A (AISI 305) or V4A (AISI 316) grades. A wide selection of fittings and connectors is also available in the same materials, ensuring they are perfectly compatible with HAHN oil brakes.

Keeping Pace with the Times

“Mobility and the transportation transition are top priorities, especially in urban areas, where new solutions are urgently needed. With HAHN’s oil brake, aidoo’s chassis technology can make an innovative contribution to increasing cargo transport by bicycle. A prime example of successful collaboration between industry and the bicycle sector.”

Turan Dardagan, Consultant at Projekthaus aidoo, Seelbach