It's a rare occasion when you can sit down with the man behind the bike. In this case, I had the chance to chat with SCOTT's Cyril Beaulieu, the man whose mind spawned the bike that will likely power the new GreenEdge super-sprinter team to many victories in 2012.
Tell me about the Foil, your flagship bike.
The main target was to build a new road frame improving on aerodynamics. The target was not to use a time trial bike adapted for the road. We noticed that the typical aero road bike was very narrow and resembled a time trial bike in many ways. Our target was to improve on this. We wanted to make an aero bike that was good in all road conditions: flat, downhill, climbing, everything.
We tried to find a new concept to improve aerodynamics without using a complete aero profile, which is very bad for stiffness and weight. We used computer 3D software to simulate flow around tubes and to calculate the drag and the separation of the flow. We get a good background with this simulation information, then we validate it in the wind tunnel. With this information, we can come up with a good solution.
In our first study, we wanted to find out which shape would be the best to optimize our three parameters: stiffness, weight, and aerodynamics. So, I simulated a round tube, a complete NACA profile like in the Plasma, and then I tried to analyze the barrier of the airflow on the tube and the separation. On the round tube, you can see the flow creating a lot of turbulence and separating quite early. Early in this case is in the middle of the tube. That creates a lot of negative force and a big tail with some turbulence. On the complete NACA profile, you can see that there is a very laminar flow around the tubing, which stays attached for a very long time to the tail. The separation is very narrow. That reduces the negative force on the back of the tube.
It's obviously extremely aerodynamic, but we have two main constraints: the first are the UCI rules and the second: we need a good ratio between width and depth to get a good stiffness and keep some comfort in the bike.
Moving towards a workable solution, our first idea was to use the leading edge of the NACA profile. That shape attacks air on the front and creates lamination on the side. We tried to reduce this shape with a different rear part and control the separation of the flow. Doing this, we got a specific curvature on the side with a specific radius on the back to control where the air is attached to the shape.
I simulated more than 70 different profiles on different bikes: concave, convex, flat, different radii, different curvature, etc. Then, step by step, I found a good compromise. Step by step, I got to the best shape. I did some SLA to validate those tubes separately in the wind tunnel to validate the calculations and the reality in the wind tunnel. After that, I defined all the tubes for all positions: downtime, seattube, seatstay, chainstay, everything. I defined the ratio we used, and where we cut the tube and what kind of transitions would be made between the leading edge and tail. After that, I built a complete frame.
The construction allows us to reduce the weight as much as possible. I tried to build it with some continuity, for the downtime and chainstays to translate the power, get more stiffness, less stress. On this frame, we get 20-30% less stress than the Addict, and it's stiffer. To top it off, we are close to the Addict in weight. It's 840 grams. It's still a very light road bike with the same level of aerodynamics as our competitors. We place this bike in a very good position with weight and stiffness. If you compare these three parameters, we come eye level with everyone. It might not be quite as aerodynamic as a Cervelo or a Felt - it's close - but if you throw weight and stiffness in to the equation, there's no comparison if you take all three into account.
The main goal was to create an aerodynamic bike without any compromise in performance for all conditions - we accomplished that. It's a very, very versatile bike.
What do you see for GreenEdge for next year? Do you hope to get some more feedback on the bike from them?
HTC rode this bike in 2010. At the beginning, they asked me for a bike that was as stiff as possible, so I built something with a specific layup. One month later, they asked me to use a normal layup, because it was too stiff. I told them originally that the first Foil was more than stiff enough, but with their request, I reinforced another layer for them. Of course, it was too hard. The current version on the market is the same one that we will use for GreenEdge. It's a very good product. For sure, it's a great bike for a sprinter. Nothing moves. I expect we'll get some feedback, and we'll improve upon it, but the current lay-up is already very well optimized. We get a very good balance of stiffness, comfort, and aerodynamics from front to rear on this bike.
What do you see for the future? This is an amazing bike. It meets all your parameters. Where to from here?
We can develop more specific bikes. This one is more improved on aerodynamics. For sure we like it, and we don't know what we're going to do to improve on this bike specifically. Maybe we'll aim toward a lighter bike, more specific for the mountains. Every time we optimize, it gets harder to do better. This one could be updated in two or three years for sure, but for now, I'm satisfied.
Looking ahead, we'll probably incorporate some new details, perhaps a new design, upgrade some stuff. New studies on aerodynamics could yield new possibilities as well. Shimano's electronic system opens up a new realm of integration. I'm not sure trying to integrate for every stem or seat post is the way to go though.
Sometimes, the solution we end up with is not so clear or so easy. I'm focused more on the bigger view of the bike - how to make it a better feeling bike than we already have.
I'm already working on a new bike, but I can't tell you the aim of it just yet. I can say, however, that I think we can make a very light bike with good stiffness. It's an entirely different target. I think there is room for an aero bike, a light bike, and a comfort bike. We can play with what components we like to accomplish this.
In 2012 you'll be working again with another top level team. Does that bring pressure to have more than one bike? Like something for Paris-Roubaix?
Yeah. I will work on specific bikes for specific races. The Foil is surprisingly comfortable on the cobbles though. The seat post is not the best we can use for those situations, so we will try to find a system to make it easier for the riders on the cobbles for sure. Stuff like that.
It kind of makes the design process simpler, no? For a race like Paris-Roubaix, a more comfort-oriented bike can be made, which will suit the demands of the race, but will also appeal to consumers… Comfort for normal roads is fine, but for a race like Paris-Roubaix, as I said before, we will try to design a new seat post to improve the comfort. Perhaps we'll redo the new bike. We'll see.
When did the idea of the Foil come about?
Highroad asked for a new bike in 2009. They wanted a very fast bike. The target was to get a faster bike than the Addict. The Addict was already very old at that point, so it was a fair request. To get a fast bike, we needed what I mentioned earlier: light, stiff, and aerodynamic. With those three parameters, we got started. Comfort is on the second tier of importance behind those top three goals. The rider prefers it that way.
How long did it take from the team's request to the whole development process?
As fast as possible. For this one, I took time to research the concept for around three months, then I built the frame over the next three months or so. So, six months of pure development and then validation. We took some risks, but at the same time, we continued to change some things, and then we arrived to nine months and the semi-finished product. I say that, because we were still working on it all the way until the frame went into mass production. We got some frames to the team for the 2010 Tour de France in 2010, but I continued to work on the bike all the way until this year to improve some details.
So, to get the bike most of the way to where we wanted it, it took nine months, but at the end, we worked on it for almost two years (not 100% of the time, of course) adapting some details.
How did you get into this line of work?
I raced at the elite level in France, and then I got a PhD in carbon and materials. I've been working on bikes for more than ten years now.
You can get a PhD in carbon?
Yes. Mine is more applied solutions with the process on optimization of structure. I focus a lot on this kind of activity. It's very focused for bicycles.
I guess that makes you qualified!
I worked five years in carbon production too, so I know the process, and I have a good background in production and different processes. I have also designed some machines. When you know all the processes from the beginning to the finish, it's interesting.
I started out with LOOK. I developed a product. I did a prototype by myself. I drew the mold and the machine. I started the project from the beginning and took it to the end. I did the carbon layup by myself. It was a very good experience to get to know the structure and how it works very well. If I didn't get this experience, it would be difficult to imagine the problems you can encounter.
Now, we work with a Chinese factory. They draw the mold, but I tell them how to draw it. They send me the drawing, and I change some thing. We do not do everything by ourselves. It was a good opportunity to learn at the beginning though. Now, when I go to the factory, I know what works and what doesn't - I have the confidence and knowledge to accomplish what needs to be done.