The drag force acting on a cyclist or indeed any object is defined as follows;. Air density reduces as temperature increases, as shown in figure 1. Therefore, raising the temperature inside the velodrome will reduce the drag force acting on the rider, allowing them to go faster.
Figure 1 shows how temperature effects the drag acting on a track cyclist using typical values for the area and drag coefficient. Reducing the resistive force acting a cyclist will give the greatest time advantage on longer distance events, such as the individual pursuit which is raced over 4 km. An in house track cycling research tool, developed by Dr Rich Lukes, was used to predict the effect of increasing the air temperature in the individual pursuit.
Increasing the temperature from 20 degrees to 25 degrees produced a time advantage of approximatley 1. The interesting thing to note is, the higher temperature will aid all athletes in breaking records, whilst giving them no advantage over their immediate competitors.
Sports engineers are renowned for giving individual athletes or teams an advantage by improving their equipment. The engineers behind the velodrome have gone a step further by building a facility which should increase the performance of all competitors. In particular, the air temperature inside the velodrome will be higher than usual to reduce the drag force acting on the cyclists.
Increasing the temperature from 20 degrees to 25 degrees would give a world-class cyclist a performance advantage of approximately 1. My prediction, records will be broken in the velodrome in 2o12, particularly in the longer distance events. A very good article indeed and very interesting to read.
Firstly to the actual athlete themselves and how quickly they tire in the elevated temperature. Secondly the effect of the extra grip the tyres are likely to have on the track due to the increased rubber temperature and whether this would lead to any increase in rolling resistance of the bike? I am an engineer but certainly have little expertise in this field. This is what he offered:. I too was intrigued by the raised temperature in the London velodrome supposedly to improve performance of the cyclists.
As you can see altitude is a prime determinant, then temperature followed by humidity. If you want more on the maths, see here. Aero gains vs Aerobic performance losses So far so good, just to to altitude, find a covered velodrome and turn up the heating, right? Only altitude brings other other problems. The very gains in aerodynamics from the reduced air density mean a reduction in the partial pressure of oxygen and consequently your VO2 Max or aerobic performance declines.
So for all the gains in aerodynamics there are reductions in physiological performance. This alone can account for that slow feeling in winter, especially when dressed in bulky gear. You can use the science for Strava high scores, just venture out on warm humid day for a natural advantage. Wind adjustment A quick mention of the wind.
Watching the Winter Olympics you might see the ski jump and how wind conditions are included in the calculation of the total points. For me no adjustment should be made. For starters the calculation would be a theoretical nightmare and a practical impossibility to measure windspeed around the course.
In the ski jump alone they take five measurements, a 10km TT course might need five or maybe 50 measurements.
Note the weather all year long will affect performance. Amateur meteorology can help picking winners for a time trial. If you did want to go for the record then the Aguascalientes velodrome, built in , is a good pick offering reduced air density and the controlled conditions of an indoor arena but not being so high to diminish aerobic performance too much.
I have my doubts about aerodynamics testing in a wind tunnel, due to it being a controlled indoor environment, whereas real-world conditions are not controlled but constantly variable, just as you mention above. Overlooking his epo history, a good point was made that the longer track means fewer turns. So for all the things that can be controlled, i wonder how important that factor would be as well? Would it be worth 10 meters? Enough to set a new record? And my thanks to Inrng for pointing out the site.
Of course some tunnels are better than others, and tunnel design and test process matters, but for a well set up tunnel, the results most definitely reflect real world physics, which should not surprise since the physics is the same. An issue with tunnel testing is whether a position set up in a tunnel is sustainable when riding for longer durations and under the sort of effort level when racing. Each method has great advantages, and is now sufficiently sophisticated to tease out quite small variations and enable performance optimisation.
As for outdoor variability, well fortunately the technology now exists to measure with high frequency and with precision the speed, power and wind velocity speed and direction while on a bike, and to closely examine the actual impact to performance under variable conditions. Guess what we find? The G-forces are there but are not horrible at hour record speeds, but that little press times per hour has some impact.
An example of roundabouts: for instance when using a longer track, the centre of mass of the rider has to travel further on longer tracks the lean angle in the turns is less than on a shorter track greater lean angle. It may not seem a lot, but it does add up. So if the lean angle is reduced i. There are other factors such as the greater natural variability in wheel speed and cadence between straights and turns on shorter track versus longer ones, so a rider needs to train to manage those transitions.
And riding good lines matters. The entire Formula 1 grid disagrees with you… obviously there are differences from wind tunnel to real world, but the technology is certainly developed enough to correctly calculate and adjust statistically for these differences. F1 is a very different beast — velocity alone makes the aerodynamics so much more important. But to your point, F1 tests the whole system.
The car is very easy to define and is the sum total of the elements involved. Testing two different diffusers on the car gives clear differences and allows off-car correlation of other diffuser results to occur because the rest of the car is aerodynamically constant, unlike a cyclist.
Depends on the bike and the rider etc etc of course. While I agree that the purported benefits are not as great as they are laid out aero benefits are not additive! It is a matter of degrees though. If I ride at 20kph, they are there but not significant. If I am riding at 50kph they are there and significant. For the average Joe, a gain of 1 second in a 40km TT is not a big deal … for Tony Martin it is the difference between rainbow stripes and silver … no matter how you slice that, it is significant.
Alec makes a great point about sustainability. I have seen hundreds of riders in long tail aero helmets with their heads turtled and the tail sticking up in the air. Thus, they are taking a piece of equipment that could save them a dozen seconds or more in a TT and converting it to one that will cost them the same additional time. It is only aero if you can maintain the position.
Otherwise, it is bling …. The lower air density degrades both lift and engine power, unlike in cycling, where it works mostly in favour of the record breaker at least for altitudes below the onset of hypoxia at ca. Thanks, there are a lot of calculations on the subject for aviation where obviously it matters more than mere sporting performance.
Thunder and lightning might offer the quickest-possible conditions for track cycling in an arena where speed is influenced by a vast range of factors, many derived from the weather outside.
For performances indoors to be governed partly by meteorology might seem odd, if your time is not spent immersed in the data which now drives elite sport. But the waking hours of Esme Taylor, an English Institute of Sport external-link physiologist, are consumed harvesting the tiniest details about how Britain's finest are performing and what affects them.
Armed with laptops, small boxes affixed to bikes and other sensors, she and her colleagues amassed an arsenal of information. That's affected by the weather outside. Some of that is related to track geometry, but a lot is related to the weather. There is no air-conditioning at the velodrome, which prides itself on a system of "natural ventilation" to create a constant track temperature of around 28 degrees Celsius. You get a cooling effect when competing from the air rushing around you, so while it may sound quite warm, it isn't for them.
Organisers encountered some difficulty in maintaining that fixed temperature during the World Cup, which doubled as an Olympic test event. Taylor and the British Cycling team noticed the temperature fluctuate, including a drop in Friday's evening session, later ascribed in reports to stewards accidentally opening the wrong doors external-link to let people leave early. Temperature, though, is not the only influence.
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