An Italian bike manufacturer has 3D printed a bike which will be used in an upcoming race, and as the title says, it has biomimicry features inspired by a humpback whale.
Read on to learn how nature has inspired engineers to create this racing bike.
Tubercles
Bike manufacturer Pinarello, who are based in a town called Villorba, just north of Venice, have developed their latest racing bike, the Bolide F HR 3D, with the aid of metal AM and a little inspiration from nature. Specifically, the racing bike has the addition of tubercles, which are the knobbly things that you can see on the front of a humpback whale’s fin.
It has long been known that the tubercles on a whale help to increase its maneuverability in the water, permitting rapid turns whilst in motion.
The Italian bike company has added these knobbly protrusions to the leading edge of certain components on their new bike with the aim of reducing drag as the bike is in motion.
You can see the printed tubercles in the image below. They are the protrusions at the leading face of the vertical bar.
Tubercles work on a principle called the “tubercle effect” (duh), which utilizes the protrusions in guiding the fluid flow into narrower streams over the body in question, be it a whale fin, a bike frame, or even an aircraft wing. It also prevents the fluid stream from moving up and down the body, which can result in fluid vortices off the tips of the body. Vortices are bad. They are lossy.
The bike engineers realized that the alternating movement of the rider’s legs produced an uneven airflow around the frame, and so added the tubercles to improve the aerodynamics of the bike.
“This alternating airflow makes it very difficult for the air to stay attached to the seat tube,” said Pinarello.
“The consequence is that the airflow is constantly separating from the seat tube, creating a large low-pressure area around it which in turn creates large amounts of drag. This is partly why the combined drag of the seat tube and seat post is almost 40% of the total drag of the frame and fork.”
Scalmalloy
The bike was printed with Scalmalloy metal, which is an aerospace alloy developed by Airbus, and has already found fans in the world of cycling, as we reported here. It is currently the strongest 3D printed aluminium available.
In case you were wondering what a whale tubercle looks like, you can see them in this picture.
The stiffness of the material and the design is critical in racing, as it reduces scrubbing on the tyres on the downstroke of the rider’s pedalling. This can cause literal centimeters every time the pedal is pushed down, which is obviously not great.
The bike has been designed to the exact specifications of rider Filippo Ganna to maximize comfort in his upcoming race event, the Hour Record in Grenchen, Switzerland
Comfort is critical in this kind of race, as it permits the rider to go faster for longer. This is quite important in the Hour Record, as the entire point of the race is to ride as far as possible in the space of one hour.
The current record holder, Daniel Bigham has managed to ride 55.548 km in that one hour. Bigham is a performance engineer who is also working for Ganna’s racing team, the UCI WorldTeam INEOS Grenadiers.
Ganna himself will attempt his own tubercle-assisted record on 8th October 2022.
