Hello, welcome back to Sports & Building Aerodynamics, in the week on cycling aerodynamics. In this module we have a very special treat for you. We actually have an interview with two professional cycling coaches, who themselves were top international cyclists in the past, and who are now coaching two of the most talented and most well-known cycling teams in the world. Koos Moerenhout has been a professional cyclist for 15 years with a very impressive track record. He has been two times the Dutch National Champion in road race. And he achieved twice the sixth place in the World Championship individual time trial. His personal favorite competition is individual and team time trial. Since 2013, he's the team manager and team coach of the Rabo Liv team for women, which is a team around multifold World and Olympic Champion Marianne Vos. But the team is more than Marianne Vos alone. It's a very strong team that in 2013 won the World Cup for teams and achieved a second place in the World Championship team time trial. Mathieu Heijboer has been a professional cyclist in the well-known top-cycling team Cofidis. In 2007, he graduated as movement scientist from the University of Maastricht. He is currently the trainer and the sport physiologist of the well-known Dutch top-cycling team Belkin, well-known around the world from the Tour de France and also excellent performances in the UCI World Tour. >> In our team we use wind-tunnel experiments almost every year to measure the drag and to optimize position, yes. >> In women's cycling the budgets are a little bit less than than in men's cycling. So we have to watch the budget also. So it's not that obvious that we can take women into wind-tunnel tests. A few of them already did this in the past, like Marianne Vos. But we are certainly interested in the results like this and we are trying to put our best riders, also for giving them the opportunity to do a wind-tunnel test. >> To my knowledge, we haven't used computer simulations, ever, for testing aerodynamics. >> The same for us. We recently got involved with it at the TU Einhoven, but that was a very new experience for us. >> Of course, it would be very interesting to do wind-tunnel testing with the whole team for the time trials, team time trials. But well, in practice it's a bit difficult to put six riders behind each other in A wind tunnel. Normally, there's not enough room for that. >> Yeah that's of course true, and I think it can be very interesting also for us. Because as you know details make the difference at the end, but you also have to look at the practical side of it. >> Well normally in team time trials we decided with the riders that they, when they pull off, they take a large distance from the group and then they come slowly back to the group. So that they can jump in the last wheel at the end. But when the riders get more tired, they tend to go really close to the group and try to get some less air resistance while going back to the last position. >> And that is a little bit conflicting with the theory which is presented here I think. Because, like what you say, when they get more tired they tend to go to the group, with the idea in mind to maintain a little bit more speed from the group. But if you look at the picture here it's just the opposite. So that's something. >> Yeah, it looks like that they even have to push harder to keep the same speed because they have more air resistance when they are close to the group. >> So, that's going to be a huge battle for us to try to keep them away from the group, when coming back. >> Keep them away from the group, yeah. I don't think the effect is known that a leading rider has advantage when a rider is in his wheel. Do you notice? >> Most of the time, it's only irritating for the first rider, when I translate it to a road race, for instance. When it happens that in the breakaway of two riders, the first one works, the second one doesn't work with team tactics in mind or whatsoever. And the first one gets really frustrated because the other one is not cooperating. So we might bend this a little bit and take it to an advantage that even even if you have somebody in the wheel, it gives you a small advantage. But then okay, then there is also the finish line, so we have to figure something out, how to compare that again with the team tactics. >> So I think it's the best idea that when our second rider doesn't want to work, you take him to one K (= kilometer) before the end and then you drop him. >> Then you have to drop him. >> But that's going to be difficult probably, because he will save a lot of energy staying in the wheel. >> Yeah. Yeah, when I look at this slide this looks logical to me. When you're in the wheel, then you have less air resistance, and the further you go back, the less air resistance you have. The only thing that's a little surprising, is that also the rider in the front has to produce less power, because he has some riders behind him. >> For me that's also kind of a novelty, because that's not known, for me at least. >> Yeah, when I look at this slide then, something new appears, for me at least. It is that it's not the last rider, when you have a group of six, it's not the last rider that has the most advantage, but it is the second last rider that has the most advantage. >> Like here you see it in the figures. And otherwise it's yeah, when you think back in an echelon or in a team time trial, when you come off the front and you have to pick in at last position. >> Yeah. >> It always takes a lot of energy. First you need to recover from your work you did in the front, and at the back there are times that you have to do a small sprint to really come close in to the wheel. So the last position is not really the most relaxing, because you need to recover a little bit. But now here it's shown that, also in figures, that the second last position is more advantageous. So compared to practice, for me it feels the same, but with other things in mind. >> Yeah. Yeah. Yeah, I think this is really nice information. But in practice, you also need the sixth rider to work in front, so you can't leave him all the time behind to give the fifth rider the most advantage. >> And if you would do it like that then you lose two riders. >> Yeah. >> The second last one and, and the last one. So that's going to be difficult. Maybe, in road racing when you pull a sprint or do a lead-out towards a climb or whatsoever, maybe we can use it in that kind of way. >> Yeah. I think so too. So if I look at this image, I see the overpressure of the second rider that gives in fact an advantage to the first rider unless he's really close, of course, to the first rider, but this makes it logical that the first rider has an advantage because of the rider behind him. >> Yeah. >> And is it also with more riders, or for instance if the team car follows a single time trialist, does it work the same do you think? >> I think it's yes, I think it's the same and even more, I think, when you have a team car behind the individual rider. It will give him a lot of advantage. >> So but then the UCI rules come into play and my idea was, I think you have to stay 25 meters behind the rider. I wonder if, I can't imagine that it's still advantageous then with 25 meters. >> I cannot imagine either that with 25 meters behind the rider you can still have an advantage. On the other hand, I don't think that the UCI invented this rule because of the overpressure and underpressure, but more because of safety reasons. >> I think so too. >> Well, if we see the the results of the team time trial in the Tour de France, when Orica Greenedge won with less than a second before Omega Pharma-Quick Step. And then in the end of the season Omega Pharma-Quick Step won with less than a second the World Championships, it makes clear that research in aerodynamics is very important, and I think even the smallest differences make whether you win or you lose. >> Yeah, if you look at these results, the first three are within 10 seconds from each other in a big effort like that. So, in the beginning it's, of course you have to take care of the basics, that the team is really ready for team time trials. That they know the tactics, but also the techniques. And then of course, research like this can help you a lot in winning that one second, making that difference. As Belkin also is doing, the same as us here, they are investigating clothing, the bikes, equipment, everything to be as fast as you can and as aerodynamic as you can. And I think researches like this can be very valuable and helpful to gaining that last detail. Because every team in top level is watching the details is, is watching the basics, so in the end the details will make the difference.