Eldron Posted July 31, 2018 Posted July 31, 2018 Here is a graph that looks too high...but is consistent with the calculator in terms of wind being exponential. The difference looks to be around 45-50% more power for the 2014 record. Wiggins reckons he needed to produce around 440w for his record of 54.526 km in 2015.
DieselnDust Posted July 31, 2018 Posted July 31, 2018 I found a neat calculator online which gives you power required to maintain speed. 44.2km/hr requires 243w51.1km/hr requires 374w. I'm sure some assumptions are off because those power figures are way too low but it does show the exponential nature of wind resistance. It requires 53% more power for the 2014 record. Those numbers would be average Watts and therefore pretty impressive
rudi-h Posted July 31, 2018 Posted July 31, 2018 Eldron is on the money... the increase in kinetic energy (which is equivalent to power) between 44.2 km/h and 51.1 km/h is +33%. So that means ~22% improvement (after you subtract your 10.5% training / nutrition correction ) in aerodynamic efficiency as bike weight has almost no relevance in track cycling. On hills there would also be a big difference due to better gearing and lighter frames.
Longbarn Killer Posted July 31, 2018 Posted July 31, 2018 1919 Tdf ave speed 24.056 km/h2017 Tdf ave speed 40.210 km/hBike technology cannot get the credit for this I'm afraid. Much better road surfaces allowing for higher average speed, massive advancements in training, riders earning a living from cycling (hence more time to train) and dare I say it.....................................drugs
scotty Posted July 31, 2018 Posted July 31, 2018 1919 Tdf ave speed 24.056 km/h2017 Tdf ave speed 40.210 km/hBetter roads, better bikes, better nutrition, better training, near skeleton participants on lighter bikes (TT bikes were unheard of) with better gearing and riders in 1919 had to do all the support themselves with no team mates to support them.
Eldron Posted July 31, 2018 Posted July 31, 2018 Bike technology cannot get the credit for this I'm afraid. Much better road surfaces allowing for higher average speed, massive advancements in training, riders earning a living from cycling (hence more time to train) and dare I say it.....................................drugs They are just incomparable. Apart from the roads being gravel/cobbled riders had to fix their own punctures (which happened often), carry their own spares, no outside assistance allowed (which included welding your own bike back together), stages were generally over 250km long, bikes had no gears (or the rider had to stop and change the gear manually). Proper apples and oranges comparison.
Hardi Posted July 31, 2018 Posted July 31, 2018 I think technology increased the endurance "factor" of riders.Comfort = less fatigue = more time at the higher AVG speeds Bike weight is irrelevant when maintaining a constant speed on a flat surface.The Bike's Aerodynamics has obviously improved, but the main drag comes from the body anyway. 3% could be correct If your think the bike is less than 7% of the moving object
Andrew Steer Posted July 31, 2018 Posted July 31, 2018 I've been reading adverts about bike tech improvements for well over a decade, every year 4-5% faster, stiffer, lighter... and yet: http://www.stickybottle.com/blogs/cycling-fastest-times-alpe-dhuez/ Anti-doping is doing something clearly... and maybe drugs do/did work pretty well after all PS: That first Tour de France was something like 5500km's over far fewer stages - not really worth comparing, post World War 2 might be a more worthwhile comparison
Fat Boab Posted July 31, 2018 Posted July 31, 2018 Some interesting interpretations of Newtonian mechanics in this thread. Let me offer a view.... Power to overcome aerodynamic resistance is a 3rd order power law. (Infact it's not quite 3rd order, as drag coefficient varies with relative velocity but for small changes in bike speed, we can consider it to be independent of relative velocity). 3rd order power laws are not exponential. We often incorrectly term things 'exponential', such as the graph in post #17, to suggest they are non-linear. The power-velocity relationship is non-linear but its not exponential.
RocknRolla Posted July 31, 2018 Posted July 31, 2018 I blame beer for the negative improvement on my personal cycling development.Blame is used loosely here. But saying I enjoy beer for the negative improvement on my personal cycling does not sound right, although it is correct.
Eldron Posted July 31, 2018 Posted July 31, 2018 Some interesting interpretations of Newtonian mechanics in this thread. Let me offer a view.... Power to overcome aerodynamic resistance is a 3rd order power law. (Infact it's not quite 3rd order, as drag coefficient varies with relative velocity but for small changes in bike speed, we can consider it to be independent of relative velocity). 3rd order power laws are not exponential. We often incorrectly term things 'exponential', such as the graph in post #17, to suggest they are non-linear. The power-velocity relationship is non-linear but its not exponential. Interesting... I have always thought that anything with an exponent could be termed exponential regardless of whether the exponent was 2 or 3 (or a fraction of either). I'm not sure I believe (or understand!) you
DieselnDust Posted July 31, 2018 Posted July 31, 2018 Some interesting interpretations of Newtonian mechanics in this thread. Let me offer a view.... Power to overcome aerodynamic resistance is a 3rd order power law. (Infact it's not quite 3rd order, as drag coefficient varies with relative velocity but for small changes in bike speed, we can consider it to be independent of relative velocity). 3rd order power laws are not exponential. We often incorrectly term things 'exponential', such as the graph in post #17, to suggest they are non-linear. The power-velocity relationship is non-linear but its not exponential. Oh jummy a maths debate. Normalised data may be presented as non linear. I'd agree that the data should be at least 3Rd order
Fat Boab Posted July 31, 2018 Posted July 31, 2018 Interesting... I have always thought that anything with an exponent could be termed exponential regardless of whether the exponent was 2 or 3 (or a fraction of either). I'm not sure I believe (or understand!) you As I understand it (?), a power law is of the form y = x^n, where n=3 in this case. An exponential function is of the form y = c^x. It gets very confusing when we start inter-changing exponential, exponent, exp(x) etc.
Odinson Posted July 31, 2018 Posted July 31, 2018 Some interesting interpretations of Newtonian mechanics in this thread. Let me offer a view.... Power to overcome aerodynamic resistance is a 3rd order power law. (Infact it's not quite 3rd order, as drag coefficient varies with relative velocity but for small changes in bike speed, we can consider it to be independent of relative velocity). 3rd order power laws are not exponential. We often incorrectly term things 'exponential', such as the graph in post #17, to suggest they are non-linear. The power-velocity relationship is non-linear but its not exponential.
Eldron Posted July 31, 2018 Posted July 31, 2018 As I understand it (?), a power law is of the form y = x^n, where n=3 in this case. An exponential function is of the form y = c^x. It gets very confusing when we start inter-changing exponential, exponent, exp(x) etc. My googleresearch revealed this. If we go by the dictionary meaning then anything that has a curve is effectively exponential (increasing at an increasing rate). Mathematically I can't find a clear case either way. From now on and in future I'm going to go with this "wind resistance is non linear" :-)
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