the bike and the secrets – Corriere.it

It costs like a high-end SUV, but has no engine. In order to overcome the resistance of the wind and go fast it does not consume gasoline but is inspired by the movement of one of the most fascinating animals on the planet, the humpback whale (a kind of whale). Paying the modest sum of 60 thousand euros (and waiting many months to receive it) any enthusiast can buy (as per the regulations of the International Cycling Union) the Bolide F Hr 3D built by the Venetian Pinarello with which Filippo Ganna (who is the champion of Verbania) will try on Saturday 8 October at the Grenchen velodrome (in Switzerland) to set the new World Record of the Hour on the track and, if possible, to be the first to break down the wall of 56 kilometers.

Pippo’s Bolide is extraordinarily normal, in the sense that the geometry of the frame must strictly comply with the rules established by the UCI for this test and in particular the dimensional ratio between the various tubes because the position does not contradict (as in the case of the bikes of Moser, Rominger and Boardman in the eighties and nineties when the racer was smeared atrociously on the bike) the natural shape of the frame.

The frame is a monocoque printed entirely (the first time this happens) in 3D but (again great news) not in carbon fiber. The material is a new alloy based on scandium, aluminum and magnesium renamed without too much imagination scalmalloy
. The advantage is that, with the same strength and lightness (we are talking about aeronautical alloys), by going to print with the scalmalloy it is possible to create interlocking angles between the various parts (glued with epoxy resins) that the versatile carbon made impossible. From this point of view, for the first time, there were no limits in passing from the Cad drawing to the mold of the single piece. The goal is always the same: to make the man + bike complex as aerodynamic as possible, which is necessary when traveling at speeds close to 60 kilometers per hour and even inside a velodrome you face enormous air resistance.

The cyclist’s legs move up and down all the time, following a rather complex but very repetitive trajectory – explain the designers of the Venetian house that supplies the bikes to Team Ineos -. The air flows around the seat tube and seat post in a never linear way: continuously displaced by the rider’s legs, which deflect the flow. This alternating flow of air makes it very difficult for air to “stick” to the seat tube. Then the airflow constantly moves away from the seat tube, creating a large low pressure zone which unfortunately generates large amounts of aerodynamic drag.

To combat air resistance, in Pinarello they studied the movement of that wonderful marine mammal that the humpback whale. Humpback whales are known for their ability to make very tight turns while swimming – they add in Pinarello – and for their spectacular leaps out of the water. The researchers found that the tubercles (the protrusions at the front of the fins) contribute significantly to this ability. At the University of Adelaide studying these particular shapes of fins since 2006: first they found them an application for aircraft wings and fans, then for bicycle frames. They also observed how the airflow around the seat tube alternates at a wide angle, resulting in flow separation and increased drag. They were then able to discover that small ridges can minimize this separation effect and reduce aerodynamic drag, generating eddies of current in the depressions between the protuberances, making sure that the flow behind the “spouts” remains as tight as possible.

And the small ridges will appear on Saturday on the bike of the world and Olympic champion of the pursuit who, floating like a marine mammal, will try to bring back to Italy a title that only two Azzurri have won in history: Fausto Coppi and Ercole Baldini.