2023 Award Winners
Award-winning project: 3X3 NINE – Test bench development for the next generation of bicycle hub gears
Project partners: H+B Hightech GmbH, Adelmannsfelden | Steinbeis Transfer Center Innovative Drive Technology and Waste Heat Utilization (IAA), Aalen
H+B Hightech GmbH has specialised in high-precision engine components for internal combustion engines since 2014. The medium-sized company from Adelmannsfelden is now also applying its expertise to the cycling market: under the 3X3 brand, H+B Hightech offers innovative cycling components of a high technical standard, all manufactured in-house. At the heart of the brand is the 3X3 NINE wheel hub gearbox. To develop a test bench for testing bicycle gearboxes, the company sought expert assistance from the Steinbeis Transfer Centre for Innovative Drive Technology and Waste Heat Utilisation (IAA) in Aalen, which specialises in the development and testing of drive units.
In the test rig designed, a drive motor drives a pulley via a drive shaft; this pulley is mounted on a bearing block. The test gearbox is driven via belts and pulleys fitted to the input and output shafts. It is held in place by a rigid axle, just as is the case on a bicycle. Two measuring flanges are used to determine the rotational speeds and torques in the area of the bearing block. The test rig was designed as a dedicated hub test rig; the test cycles simulate a mileage of 45,000 km. The wheel hub gearbox can be driven via belts or a chain. The gearboxes can be changed quickly and flexibly using a quick-release system that mirrors a bicycle’s rear triangle.
As the gearbox will be available with both manual twist-shift and electronic gear changes, it was necessary to develop an electromechanical shift actuator. In addition to analyses of the gearbox’s long-term durability, the Steinbeis team therefore carried out investigations to determine the required shifting force and shifting torque.
Unlike existing complete-bike test benches, the advantages of a hub test bench lie in extremely short set-up times and the ability to test different gears directly on the test bench. The test bench designed is therefore ideally suited to the development of a new hub gearbox.
Thanks to the extensive preparatory work, the Steinbeis team’s precise testing technology and the excellent synergy between the project partners’ areas of expertise, H+B Hightech was able to present the 3X3 NINE wheel hub gearbox to the public in July 2022 – a year earlier than planned. The hub gearbox is scheduled to go into series production in 2023. The process know-how acquired regarding in-house hub testing gives H+B Hightech a unique selling point compared to its competitors in the growing bike market. With its new ‘Bike Technology’ division, H+B Hightech aims to secure the future of its 100 employees outside the automotive industry.
The project reflects an extremely successful development partnership between Steinbeis and industry. Thanks to the project partners’ close ties to Aalen University, this knowledge is incorporated into teaching and research in an abstract form, thereby contributing to the transfer of knowledge and technology.