Development
2015
Citroen 2cv Trailing Arms on a Heavy Coffee Bike
2019
Differential Suspension Tilting Trike
2020
The Patent
2022
BiTrike
A New Promising Design
2018
Front Suspension
Tilting Trike
2020
Prototype #1
Building a Unique Trike for CECTA
2021
Prototype #2
A Build That Fails
2022
Kickstarter Live
21-11-2022
Development
2015
Citroen 2cv Trailing Arms on a Heavy Coffee Bike
2018
Front Suspension
Tilting Trike
2019
Differential Suspension Tilting Trike
2020
Prototype #1
Building a Unique Trike for CECTA
2020
The Patent
2021
Prototype #2
A Build That Fails
2022
BiTrike
A New Promising Design
2022
Kickstarter Live
21-11-2022
The 2CV Coffee Bike
2015
The adventure begins, with the thought that tricycles deserve a second look. Τhe opportunity to experiment on trikes came at 2015, when an order for a coffee bike was made. In this particular trike a suspension system with trailing arms was used, inspired by the suspension system of Citroen 2CV. Despite all its 350 kg, it offered a unique traction experience to the young lady who was riding it. However, it was quite unstable when turning, with the risk of tipping over.
Front Suspension Tilting Trike
2018
A few years later, a two-wheel front tilting system with suspension, was designed and built for everyday commuters, who wanted on one hand to ride on three wheels, and on the other hand not to lose the bicycle experience. This design became very popular on YouTube. But while it promised comfort in the unevenness of the roads, it presented stiffness in turning and when reaching the pavement with one of the two wheels to precede, causing unpredictable twisting of the handle bar and insecurity to the rider.
However, an improved version of this particular front system is available to order for anyone who wants to turn their own bike into a trike in defiance of the above difficulties. Feel free to contact us if you are interested in the kit.
The Brainstorming
The next step was to invent a way to keep the benefits of both previous constructions eliminating the drawbacks, which took a lot of time and effort. The key element in the new three-wheeler was that the cargo should be placed between the rear wheels, in order to less affect the steering system. The trailing arms respond perfectly on rough terrain, but they need to move in reverse, when tilting in turns, so that the rider can keep constant speed when cornering.
Using a Car Differential for a Rear Suspension Tilting System
2019
It didn’t take long to come up with the idea. A differential, like those in cars, could be placed in the frame’s center and connect the wheels’ trailing arms to its planetary gears. Thanks to the angle gear drive of the planet gears and sun gears within the differential, the trailing arms of the specific tricycle acquire a dependent relationship of opposite rotation of each other, whereas the differential remains stable. So, the rider could lean his/her body in any direction he/she wanted and the tricycle would perform like a common bicycle, achieving better traction of the three wheels on the road and much better control of centrifugal forces in turns, especially at high speeds. At the same time, if an obstacle or pothole overturned the dependent relationship of the arms mentioned above by vertically displacing one of the two rear wheels, this change would be transferred as an oscillation to the system’s damper. The damper would function as suspension of the morphology and slope of the ground and would be mounted with one joint on the frame and the other on the differential.
The Prototype #1
2020
Mechanically speaking, it was a very difficult project to implement until Cecta, a film company in Greece, placed an order for such a tricycle. The idea of being able to capture steady footage despite the unevenness of the road was very tempting to them. It took a whole summer to design such a complex and innovative rear suspension tilting trike system and it turned out to be more difficult than the initial estimation, because the rear wheels work as drivetrain at the same time! After many hours of designing and in the workshop, the UTurn was born – a tricycle that used a car differential for suspension system! The performance of the bicycle at an all-terrain testing was impressive. It gave the feeling that you could ride anywhere and speed was never an issue.
The Patent
2020
It was obvious that such an innovative system had to be patented. The main reason was to register the idea and at the same time to check if anyone else in the world had thought of something similar. So on the 15th of December 2020, the patent request was submitted to the Hellenic Industrial Property Organization (OBI.gr), and 6 months later it was confirmed that the idea of using of a differential for suspension on a tricycle, was officially the first and only one in the world!
The Prototype #2
2021
Apart from the patent, at the same time a second prototype with an improved setup in the transmission and the trailing arms carrier was heading towards completion. While the first tricycle had a parallel set up, the second one would be coaxial! It was a very difficult engineering project and the implementation was a failure. Not even an experienced cyclist could ride it. When laying sideways, it needed a lot of strength to get back up. While the idea was correct, the implementation was impossible! At least with the existing capabilities at the time. When the bike carried no weight, everything worked fine. Unfortunately, nothing was the same, when the weight of the rider was on. The construction of this tricycle was almost absolutely disengaged, when a new idea for the solution emerged!
The BiTrike | All Terrain Tilting Trike
2022
The system has been reconstructed. This is a new design of the previous layout minus the differential! The trailing arms and the damper are kept in place, while they are connected using a floating pivot. A few days of testing and fine tuning were then in order, and a markedly better result came to life: The BiTrike | The all-terrain tilting trike.
