Bike Adapter: the history of the device for cycling

The idea of the Bike Adapter was born in a period of maximum inspiration in the design of devices in 2020 by Michele Praga, not only passionate about model aircraft and a skilled pilot but with a strong note of genius in his mind: he is able to see a solution where a ordinary person would see only resignation. This gift of his combined with his propensity to help people with disability problems means that he has a real volcano in full swing. And like the best geniuses, how is an idea born? Obviously in my sleep imagining and dreaming about the device.

The idea was born precisely from the need to convey normality in daily life activities and to facilitate children's introduction to prostheses it was deemed necessary to design aids for everyday life including sport, which has always been an unspeakable sign of inclusion and group.

Until then there were few good solutions to allow people without hands to ride bicycles. The few existing solutions were too complex and fragile, often made of plastic materials, which could have broken in the event of a fall, resulting in sharp and dangerous edges. At that time it made extensive use of elastic materials (TPU) for 3D printing, a practically indestructible solution, in the creation of devices. In fact, unlike normal printing materials, such as PLA, PETG and ABS, it does not have the defect of delamination and resists high temperatures. The decision was to create a joint system to be fixed to the bicycle handlebars, which was in a single piece and exploited the elasticity of the TPU as a hinge, in this way an eternal and indestructible device would be obtained. After the first sketches of the project by hand, and the first CADs on the PC, Michele started with the first print, long and slow due to the extremely soft materials... the 10 January 2021 the first Bike Adapter was adapted to the bike handlebars and ready for testing. Michele, not having any disability, did a test by putting a sock on the fist of his hand to simulate the missing limb and started walking around the street; to his great amazement his project worked! After the first test he presented the idea to the Enable community and from then on the idea was developed. It took some time to go from a prototype to a definitive device and a lot of help from another community volunteer: Alessandro Villa, an expert in 3D design and graphics.

Until now the device had only been tested on Greta, but everyone's desire was to make it usable for anyone who needed it. In fact, it was necessary to make the device scalable and adaptable to the various needs of people with different limb sizes. To solve this problem Alessandro relied on a parametric modeling software called Fusion 360 and the turning point was precisely the adjective PARAMETRIC. In fact, the recipient family is asked to take essentially six measurements: the distance between the base of the elbow and the fist in the healthy limb, the distance between the base of the elbow and the end of the stump, the circumference at the end of the stump, the circumference at the base of the stump, near the elbow, the diameter of the manubrium, and the distance between the inside crease of the elbow and the end of the stump. And, without going into too much detail, by combining sketches, extrusions, circular series, fillets and other similar gadgets, it was possible to link these measurements with the creation of the famous customized 3D file.

One of the current limits is that at the moment it has not been possible to replicate the project on another online parametric modeling software called OnShape. Also in this case there is a professional version and a free one. We have migrated the project to the OnShape platform in view of future developments as it is a "user friendly" platform. This is the step to effectively make the project international, breaking the constraints of territoriality and giving anyone who owns a printer the opportunity to create their own device. Obviously we tried to reduce and simplify the intervention of the families as much as possible during the initial phase of taking the parameters by reducing the acquisition time of the biometric parameters in just 5 minutes to avoid errors as much as possible.

The first test in January 2021 brought so much joy and hope, tears and satisfaction to the inventor and creator of the project and to all those who supported him by believing in him. It was the beginning of something beautiful, it was a moment of great strength to believe more and more in the project and how much more normal it would make the children's lives, because there is nothing more beautiful than having a nice bike ride with friends. To think that with little, both in terms of money and time, you can allow a child suffering from agenesis or trans-radial amputation to ride a bicycle is irrelevant, and the emotion is even stronger.

Article by Giulia Mariani