Steering rear wheel
Had, would, bicycle chain: No, this saying does not work with this new wheel. Because the Chainless S1 has no bike chain.
The pedals are located just behind the axle. And even more crazy: the rear wheel can be steered.
So one has to leave the young developer Sean Chan from the USA: his design of a bike is really different: In June the bike celebrates its 200th birthday.
And Chan seems to have taken the original model of Prince Karl von Drais as an example.
He had taken a wooden beam 200 years ago and attached the two wheels to the front and rear of two diagonally seated wooden forks, Drais’ was the running machine.
Model wheel of the Freiherr von Drais
The design also has a central top tube, but of aluminum, on the front and rear two fully rotatable front wheel forks are mounted.
In the middle, under the central top pipe, there is nothing. No pedal crank, no bike chain.
Only clear space between front and rear wheel, which are quite close. The whole is similar to that of the Prince of Drais.
While in the traditional diamond frame, the central triangle ensures stability and the forces acting on the pedal crank at the bottom of the triangle point, the Chainless forces act directly on the rear wheel.
Because Chan has attached the pedals directly to the rear wheel axle.
Drive via planetary gear in the rear wheel
The rear wheel contains a planetary gear, so that the driver can also choose different gears at the Chainless.
How many, the inventor is silent. The frame of the Chainless is made of aluminum, the three-spoke wheels are made of magnesium.
These are available in three sizes: 20, 24 and 26 inches. The unusual bike weighs around 11 kg.
Notable for the Chainless S1 is not only the missing bike chain, but also the unusual sitting position of the driver. It sits slightly in front of the rear wheel and therefore has to step slightly behind.
This looks quite unusual in the video and makes the question about the tenn efficiency to arise.
Speaking of efficiency: engineers from Thuringia have thought about this and have developed a crankshaft that will increase torque by up to 50 percent.
Rear wheel turns into the curve
It is also unusual that the rear wheel is placed in a front fork. In normal operation the fork is blocked.
This means that as with any other bicycle, the driver also steers the front wheel with the handlebars. By contrast, a completely different feeling is generated in the so-called RTS mode.
Then the rear fork is unlocked and can swing freely.
RTS, which stands for Rapid Turning System. Great name for a simple unlock.
The result: If you want to drive a very narrow circle, the rear wheel automatically turns to the right position.
Driving snake lines is also a special experience,and certainly needs exercise. Why, watch the video.
Bicycle is scheduled to go into series at the end of the year
And when does the unusual bicycle come onto the market?
That depends on whether or not enough bicycle fans believe in the idea in the US.
By the beginning of June, Sean Chan, with his start-up over Kickstarter, tries to collect the starting capital of 75,000 US dollars for serial production.
At the end of this year, the first series model could be built.
There are two versions: the above described standard version S1 and a version S1F, which can be folded.
For this purpose, a joint is installed in the top pipe. The S1 is about $ 1,000!