During the last Grand Prix in Malaysia, the media were surprised to see Marc Marquez riding in the rain with carbon discs.
Indeed, all MotoGP usually use steel discs when it rains, since carbon discs require, according to Brembo itself, a minimum operating temperature of 300° (See our last complete article on this subject in the magazine GP Racing #17 still on newsstands).
Eugenio Gandolfi: « 320mm discs and 340mm discs have the same starting point of operation to be efficient i.e. 300/350 degrees, but their thermal capacities are completely different; braking therefore equivalent energy dissipation, the 320 mm can reach 900 degrees while the 340 mm will reach 100 degrees less.”
As this photo shows, the motorcycle Marc Marquez was equipped in racing with 320 mm discs, those which dissipate the least heat, as well as carbon disc guards which raise the operating temperature by around sixty degrees.
The Spanish champion shared his reactions: “Before the start I decided to use the carbon brakes which gave me a chance to be stronger when braking. It was the right choice and had nothing to do with my downfall. »
To put things in order, this idea was not born randomly in the mind of Marc Marquez, because it turns out that, since the start of the weekend, Bradley Smith had used them, in the dry or the wet , without any apparent problem, quite the contrary.
So we went back to the source and asked the essential Guy Coulon, technical manager of the Monster Yamaha Tech3 team, on the why and how of what could well become a big problem next year…
Guy, we were always told you needed steel discs in the rain. Why did you try carbon discs?
Guy Coulon: “Who is this “we”? (laughs). In 1982, when I was at Elf, we were already riding with carbon brakes in endurance for 24 hours, whether dry or not. In 2000, at Donington in the pouring rain, Olivier Jacque scored 2 in carbon discs. Two years ago, Bradley Smith had them in Motegi in the rain. Formula 1 cars run on carbon in the rain...
At Sepang, we used them in testing and then in the race, and maybe that's why others did the same in the race... I suppose the manufacturer perhaps realized that it worked well and passed on the information.
Why were they used? Because the steel brakes heat up enormously and, after a few revolutions, the metal is torn off and it starts to vibrate. With carbon discs there are only advantages; it's more powerful and easier to control. Everything is going better. »
So it’s not necessarily one-off but something could happen again…
“Indeed, I think that now we will systematically ride with it, whether it rains or not. There may perhaps be special cases, but today I don't see why we wouldn't do it, given that there are only advantages. »
Because we have always said that if the discs go below 250°, they will not brake...
“In the pouring rain, we had a minimum of 170° and a maximum of 490°. In addition, we kept the 340 mm, Big Mass and the Big Mass pads (editor's note: those which dissipate the most heat) and we therefore have the reserve to have hotter discs, with the 320 mm and the small pads . We would have had temperatures shifted upwards, perhaps even too high. I think that with these discs, even at 100°, you lock the wheel when you want..."
Bradley Smith was totally convinced, even if he has reservations regarding certain circuits:
“We had a lot of problems with steel discs. I don't particularly like the feeling they give me. It's just not consistent. We are also currently suffering from some vibrations. Also, we ride 90% with carbon brakes, so I know that feeling. I know it with one finger, two or three fingers. It's just a lot more consistent, as long as I can generate temperature... In a few places, like Assen, Phillip Island or Silverstone, we wouldn't do it because there's no guarantee of generating temperature.
But here and given the amount of hard braking, we were convinced it would be OK. This is something I asked for a few years ago. It's something I keep in reserve in my pocket for when needed. You mount the disc covers and make sure they maintain the temperature inside. Then, in the first two laps, you have to be a little careful. If a little water gets on the disc, that's something that can affect it. In the first laps there were really no problems. »
So here is something put in the spotlight by its use by Marc Marquez, which was not a first but could now spread like wildfire…
