Giro, Tour and Vuelta: which countries won jerseys over the past 111 yrs

The graph below shows which countries have been successful at winning jerseys in the Giro d’Italia, the Tour de France and the Vuelta a España.

The graph shows among other things how France has been struggling since the 1990s, how Belgium (Eddy Merckx) and the Netherlands (Joop Zoetemelk, Gerrie Knetemann) did well in the 1970s and the success of the UK in the 2010s (Bradley Wiggins, Chris Froome, Mark Cavendish). If you adjust for population size (not shown), Luxembourg and Belgium are the most successful countries.

See also: Mountains and cycling culture: On winning jerseys in the Giro, Tour and Vuelta.

Method

The analysis is limited to the jerseys for the leaders of the general classification (the maglia rosa for the Giro d’Italia, the maillot jaune for the Tour de France and whatever colour the leader’s jersey had in the Vuelta a España that particular year). For each year and for each tour, for each rider who has won a jersey in that tour (regardless of how many days) a point was added to the country total of that rider’s country.
The D3 tooltip code is largely borrowed from D3 Tips and Tricks.

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Rise in Dutch cycling accidents, but Strava probably not to blame

The number of wielrenners (cyclists on racing bikes) treated at Dutch emergency departments has doubled since 2010, according to a study published today. Among a range of possible explanations the authors mention the popularity of apps like Strava:

The increasing popularity of smartphone apps like Strava, which let you keep track of cycling records for certain tracks and compare them with others, can lead to dangerous situations.

Like I said, this is just one of many possible explanations discussed in the report and the authors are by no means suggesting that Strava is a key factor causing cycling accidents. That said, the idea that Strava may have played a role doesn’t seem to be a priori absurd.

Strava was launched in 2009, but when did it become popular in the Netherlands? I couldn’t find any direct data on this, but Google trends is a plausible indicator.

The Google data are pretty clear: interest in Strava didn’t take off until February 2012 in the Netherlands (interestingly, the search volume index is highest in Limburg and Gelderland, which are also the main regions with hills in the Netherlands). As an extra check, I looked at messages at the Fiets.nl forum pages (you need to login in order to be able to search the forum) containing the search term ‘strava’. There were 10 messages prior to 1 February 2012 and 1,843 after that date, which seems to confirm the Google pattern.

By contrast, the number of wielrenners at emergency departments saw its biggest increase between 2010 and 2011. The number was stable at about 2,000 prior to 2011, but rose to 3,700 in 2011 and 4,200 in 2012. So it seems Strava was largely unknown in the Netherlands at the time when the largest increase in cycling accidents happened.

The reason for the study was a media storm last year about supposed irresponsible behaviour of wielrenners towards ‘normal’ cyclists. Car lobby club ANWB even suggested wielrenners should stay at home on sunny days.

In a survey among wielrenners, 45% said wielrenners do not sufficiently adjust their speed and 51% said wielrenners often ride in (too) wide groups. An analysis of 2,849 injury-causing accidents involving two cyclists revealed that in 24 cases a ‘normal’ cyclist got injured as a result of a collision with a wielrenner. So while many wielrenners agree that (some) wielrenners behave irresponsibly, this doesn’t seem to be a major cause of injuries among other cyclists.

Wielrenners themselves have about 2.2 injuries per 100,000 hours of activity. This is much lower than the number for all sports combined (7.1). However, 23% of wielrenners who go to the emergency department have to be treated in hospital, compared to 6% for all sports. So in terms of serious injuries, wielrennen doesn’t seem to be much safer or unsafer than other sports.

While it’s difficult to pinpoint the exact cause of the rise in accidents involving wielrenners, the authors of the report suggest the capacity of cycle paths is no longer sufficient given the rising number of cyclists, including a rise in cycling among people above 55. One of their recommendations is to create more ‘cycling highways’ for fast cyclists.

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Meer ongelukken met wielrenners, maar dat ligt waarschijnlijk niet aan Strava

Het aantal wielrenners dat op de eerste hulp terechtkomt is verdubbeld sinds 2010, zo blijkt uit een vandaag verschenen onderzoek. Naast diverse andere mogelijke verklaringen gaan de auteurs ook in op de populariteit van Strava:

Ook toenemende populariteit van smartphone apps zoals Strava, waarbij voor bepaalde trajecten fietsrecords kunnen worden bijgehouden en vergeleken met anderen, kan voor gevaarlijke situaties zorgen.

Zoals ik al zei is dit slechts één van diverse mogelijke verklaringen die in het rapport worden besproken en de auteurs suggeren zeker niet dat Strava een belangrijke oorzaak is van fietsongelukken. Dat neemt niet weg dat het op voorhand niet absurd is om te veronderstellen dat Strava een rol zou kunnen hebben gespeeld.

Strava werd in 2009 gelanceerd, maar wanneer werd het populair in Nederland? Ik kon geen directe gegevens hierover vinden, maar Google trends geeft een indicatie.

De gegevens van Google zijn duidelijk genoeg: pas vanaf februari 2012 begon Nederland belangstelling te tonen voor Strava (interessant is dat de zoekvolume index het hoogst is in Limburg en Gelderland, de belangrijkste provincies met heuvels, maar dat terzijde). Als extra check heb ik ook nog even gekeken naar berichten op het Fiets.nl forum (je moet ingelogd zijn om te kunnen zoeken) met de term ‘strava’. Er waren 10 berichten van voor 1 februari 2012 en 1.843 van daarna, wat het patroon van Google dus lijkt te bevestigen.

Het aantal wielrenners bij de eerste hulp nam vooral tussen 2010 en 2011 toe. Voor 2011 lag het aantal stabiel rond de 2.000, maar het steeg naar 3.700 in 2011 en 4.200 in 2012. Dus het ziet ernaar uit dat Strava nog nauwelijks bekend was in Nederland op het moment waarop de grootste toename aan ongelukken plaatsvond.

Aanleiding voor het vandaag verschenen onderzoek was een mediastorm vorig jaar over verondersteld onverantwoordelijk gedrag van wielrenners tegenover ‘normale’ fietsers. Autolobbyclub ANWB suggereerde zelfs dat fietsers maar thuis moeten blijven op zonnige dagen.

In een enquête onder wielrenners zei 45% dat wielrenners hun snelheid onvoldoende aanpassen aan de omstandigheden en 51% zei dat wielrenners vaak in (te) brede groepen rijden. Een analyse van 2.849 aanrijdingen met letsel tussen fietsers laat zien dat in 24 gevallen een ‘normale’ fietsers letsel heeft opgelopen als gevolg van een botsing met een wielrenner. Dus veel wielrenners zijn het er wel mee eens dat (sommige) wielrenners zich onverantwoordelijk gedragen, maar dit lijkt geen belangrijke oorzaak te zijn van letsel bij andere fietsers.

Wielrenners zelf hebben 2,2 blessures per 100.000 uur activiteit. Dat is veel lager dan het totaal voor alle sporten (7,1). Tegelijk is het wel zo dat 23% van de wielrenners die bij de eerste hulp komen vervolgens moet worden opgenomen in het ziekenhuis, tegenover 6% van alle sporters. Dus in termen van ernstig letsel lijkt wielrennen niet veel gevaarlijker of ongevaarlijker te zijn dan andere sporten.

Hoewel het lastig is om de precieze oorzaak van de stijging van het aantal ongelukken met wielrenners aan te wijzen, suggereren de auteurs van het rapport dat de fietspaden niet meer zijn berekend op het feit dat steeds meer Nederlanders fietsen (onder meer 55-plussers). Eén van hun aanbevelingen is om meer fietssnelwegen voor snelle fietsers aan te leggen.

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Problematic cycling charts

You might think the graph above is about the effort required for climbing, with those little bicycles going up the slope, but it’s not (in fact, it shows for each bicycle type how much more power is required to cycle as speed increases). Apparently, somebody added the bicycles for «fun», without giving much thought to what the graph is supposed to communicate.

The graph is from the book Cycling Science (not to be confused with the intriguing Bicycling Science), a book full of charts that explain how cycling works. Unfortunately, it contains quite a bit of chart junk and some of the graphs raise more questions than they answer.

For example, the chapter on cycling safety has a map that suggests the Netherlands is the most unsafe country for cycling. The problem is that it shows the percentage of road deaths who are cyclists, which says more about how many people cycle than about cycling safety. Another graph says Chris Boardman managed to cycle more than 56 km in an hour when he assumed a super-aerodynamic position, but that he would only manage 15 km when sitting upright. Really?

De papieren OEK

OEK
De ruim 4.500 Amsterdamse leden van de Fietsersbond krijgen drie keer per jaar het ledenblad OEK in de bus (bezorgd door vrijwilligers, waarvoor dank). De bond vraagt zich af:

of er tegenwoordig meer mensen zijn die het eigenlijk wel prima vinden om de OEK voortaan alleen digitaal te lezen en de papieren versie niet meer hoeven te ontvangen […] U kunt dan uit de distributielijst worden gehaald. Ook als u fervent voorstander bent van de papieren OEK, mag u dit laten weten.

Nou, bij deze dan. Ik lees zoveel mogelijk digitaal - boeken, kranten, rapporten. Veel praktischer. Maar voor de OEK maak ik graag een uitzondering. Je ziet dat het blad met enthousiasme in elkaar is gezet. Echt papier, niet van dat glimmende. Flink veel tekst per pagina, maar zonder dat het onleesbaar wordt. Een fijn blad om door te bladeren en te lezen.

Uiteraard ligt dat niet alleen aan het uiterlijk, maar ook aan de inhoud. In het laatste nummer bijvoorbeeld een goede analyse over de onzin van bewustwordingscampagnes, zoals de smileyborden («Wacht op groen!») die een tijdje bij stoplichten hebben gehangen. Een inventarisatie van in het asfalt gereden fietsbeldoppen op het Leidseplein. En nog veel meer (pdf).

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Script to look up the gender of Dutch first names


This script determines the gender of Dutch persons by looking up their first name in a database of the Meertens Institute. The database indicates how often the name occurred as a first name for men and women in 2010. If the name is used for women substantially more often than for men, the name will be interpreted as female – and vice versa.

The reason I wrote the script has to to with this article on how the performance of women professional road cyclists is improving. I wanted to check whether a similar trend is going on among amateur riders, more specifically, participants in the Gerrie Knetemann Classic (incidentally, the script would take Knetemann for a woman – it’s not foolproof). The results of the ride are available online, but pre-2012 editions lack information on the gender of participants. So that’s what the script was for.

Speed of participants in Knetemann Classic

The results of the analysis aren’t exactly clearcut. The number of women participants in the 150km ride varied from 36 to 46, or 5 to 8% of the participants whose gender could be determined (the percentage for 2013 was 6%). The (median) speed of women participants rose in 2013, and more so than for men, but this rather thin to speak of a trend.

Slovenians seem to buy more bicycles than the Dutch or even Danes

Mona Chalabi of the Guardian has collected data on car and bicycle sales and concludes that bicycle sales not only outnumber car sales, but that the gap has widened. The title of the article suggests the recession might play a role, but this article by Fabian Küster of the European Cyclists’ Federation - who uses the same sources - suggests it’s «an idle hope to believe that as soon as Europe’s economy recovers, car sales will go up again to pre-crisis levels».

If you look at car sales per 1,000 population, it turns out the Slovenians are Europe’s most enthusiastic bicycle buyers (that’s assuming the bicycle sale data for Slovenia are correct - this article quotes a lower number but gives no source). If you look at the bicycle sales to car sales ratio the picture changes considerably - likely because fewer cars are sold in poorer countries.

Embed code for the graph (the graph probably doesn’t work in older versions of IE):

<iframe src = "https://dirkmjk.nl//2013/bikeSales/bikeSales2.html" frameborder=0 width = 510 height=610 scrolling='no'></iframe>

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Cycling: Garmin altimeter compared to elevation databases

During a very rainy ride in Scotland, my Garmin altimeter appeared to be off: on some of the steepest climbs it failed to register any gradient. Afterwards, I tried the «elevation correction» feature on the Garmin website, which generously added over 750m to the total ascent the device had measured. This was certainly more satisfying, but it left me wondering. Can the weather affect the Garmin altimeter? And how accurate is the recalculated ascent?

Garmin’s recalculation service works basically by looking up the gps locations of your ride in an elevation database. Strava offers a similar service. Below, I analyse the Garmin and Strava recalculations for a number of rides. Note that this is only an exploratory analysis and that no firm conclusions can be drawn on the basis of this rather small set of observations. That said, here are some preliminary conclusions:

  • If you want to boost your ego, let Garmin recalculate your ascent: chances are it will add (quite) a few metres. Strava’s recalculations tend to stay closer to the original measurement. When it does make changes, it frequently lowers the number of metres you’re supposed to have climbed, especially on relatively flat rides.
  • In theory, you’d expect weather changes to affect the ascent measured by the device, because the altimeter is basically a barometer. In practice, weather changes don’t seem to have much effect on the altimeter.
  • It appears plausible that heavy rain does in fact mess with the altimeter.

In the graphs below, the colour of the dots represents the region of the ride. Red dots represent the Ronde Hoep, a flat ride to the south of Amsterdam. Blue ones represent the Kopje van Bloemendaal (north, south), the closest thing to a climb near Amsterdam (it’s not high but quite steep). Green dots represent the central area of the country and include the Utrechtse Heuvelrug, Veluwezoom, Rijk van Nijmegen and Kreis Kleve (the latter in Germany).

General

By default, the graph above shows how much the Garmin recalculation differs from the ascent measured by the device (graphs may not show in older versions of Internet Explorer). The closer a dot is to the dashed line, the the closer the recalculated ascent is to the original measurement.

For rides shown on the left part of the graph, where the device measured less than 500m ascent, Garmin’s recalculation often adds about 50 to 100% or more. With higher ascents, the recalculated ascent is closer to the original measurement, although it still tends to add about 30 to 50%. The highest dot to the far right of the graph is the rainy ride in Scotland; here Garmin’s recalculation added over 35%.

With the selector above the graph, you can select the Strava recalculation. You’ll notice the scale on the y axis changes (and the dashed line moves up). Also, a few red dots enter the graph. These are rides along the Ronde Hoep, which is a flat ride. For these rides, Garmin’s recalculation added up to 750% to the ascent measured by the device; therefore these dots were initially outside the graph area.

The Strava recalculations are similar to the Garmin ones in that the correction is larger for relatively flat rides. Unlike Garmin, Strava lowers the ascent in these cases, often by 15 to 50%. For rides where the device measured a total ascent of over 500m, the Strava recalculation tends to be pretty close to the original measurement.

Weather changes

It has been suggested that changes in the weather may affect elevation measurements. This makes sense, since the Garmin altimeter is in fact a barometer. Wikipedia says that pressure decreases by about 1.2 kPa for every 100 metres in ascent. In other words, if net atmospheric pressure would rise by 6 mBar, this would cause the device to underestimate total ascent by about 50 metres, so the theoretical effect wouldn’t seem to be huge.

The graph above shows how much recalculations differed from the original measurement, with change in pressure on the x axis. Note that the effect of recalculations is here in metres, not percent. I tried different combinations of pressure measures and recalculations and in only one case - the Garmin recalculation shown above - the correlation was statistically significant (and the regression line much steeper than the Wikipedia data would suggest), so this is not exactly firm evidence for an effect of weather change on elevation measurement.

Heavy rain

It has been suggested that heavy rain may block the sensor hole and thus affect elevation measurement. This may sound a bit weird, but I have seen the device stop registering any ascent during very heavy rain. Among the rides considered here, there are two that saw really heavy rainfall (the Scottish ride and a ride in Utrechtse Heuvelrug on 27 July). These do show some of the largest corrections, especially in the Strava recalculation. So it does seem plausible that rain does in fact affect elevation measurement.

In the spirit of true pseudoscientific enquiry, I tried to replicate the effect of heavy rain by squirting water from my bidon onto the device during a ride in Utrechtse Heuvelrug. This didn’t yield straightforward results. At first, the device registered implausibly steep gradients and it turned out it had interpreted the hump between Maarn and Doorn as 115m high, more than twice its real height. About halfway, unpredicted rain started to fall, mocking my experiment. Strava recalculation didn’t change much to the total ascent but it did correct the height of the bit between Maarn and Doorn, so it must have added some 50+ metres elsewhere. Be it as it may, the «experiment» does seem to confirm that water can do things to the altimeter.

Method

I took total ascent data measured by my Garmin Edge 800 and obtained a recalculation from the Garmin Connect and Strava websites. Subsequently, I looked up weather data from Weather Underground (as an armchair activist I do appreciate their slightly subversive name). Weather Underground offers historical weather data by location, with numerous observations per day. I wrote a Python script that looks up the data for the day and location of the ride and then selects the observations that roughly overlap with the duration of the ride. There turned out to be two limitations to the data. First, it appears that only data at the national level are available (the Scottish ride yielded data for London and all Dutch ones data for Amsterdam). Second, for the day / location combinations I tried there was no time-specific data for precipitation available, only for the entire day.

Because of these limitations, I also took an alternative approach, looking up data from the Royal Netherlands Meteorological Institute KNMI. This did yield more fine-grained data, although obviously limited to the Netherlands. In the end it turned out that it didn’t make much difference for the analysis whether KNMI or Weather Underground data is used. Code from the scripts I used for looking up weather data is here.

I tested quite a few correlations so a couple of ‘false positives’ may be expected. I didn’t statistically correct for this. Instead, I took a rather pragmatic approach: I’m cautious when there’s simply a significant correlation between two phenomena but I’m more confident when there’s a pattern to the correlations (e.g., Garmin and Strava recalculations are correlated in a similar way to another variable).

Comments

Submitted by Luca on

Please see
https://www.google.com/fusiontables/DataSource?docid=1JGlX6x_S6dl4RBCjce...

I compared the edge800 altitude readings with the Garmin and Strava corrections like you , plus the figures given by 2 popular routes building sites (which I believe use the same GPS LaoLong altitudes Garmin and Strava are referring to).

I'm totally confused, both the variations are so large that it does not even make sense to take the average of them as the true ascent value for a ride, I would have expected to find at least very narrow fluctuations between the route-building sites, disregarding the actual moving data-recording !

Submitted by Luca on

Thanks for the Strava global heatmap link, way cool

I commented on the veloviewer post my concerns about elevation data...

ciao

Submitted by DIRKMJK on

Cool - let’s see if someone will be able to shed some more light on this!

Cycling: are women catching up with men


Photo by DAVID ILIFF. License: CC-BY-SA 3.0 / via Wikimedia

In a petition already signed by 88,000 people, riders including Emma Pooley and Marianne Vos ask for women to be allowed to participate in the Tour de France and other cycling events:

We seek not to race against the men, but to have our own professional field running in conjunction with the men’s event, at the same time, over the same distances, on the same days, with modifications in start/finish times so neither gender’s race interferes with the other.

Among other things, they want to «debunk the myths of physical ‘limitations’ placed upon female athletes». So how about those limitations? In an opinion article in NRC Handelsblad, Sanne van Oosten of WOMEN Inc. argues that the world hour record for men (49.7 km) is only slightly higher than for women (46.1 km). And Guardian cycling columnist William Fotheringham observes:

Over the years there has been a convergence between the distances men and women race, as men’s professional races are becoming progressively shorter, and women’s gradually longer.

He doesn’t specify which races this applies to. The distances of the UCI world championships haven’t changed much, at least not since 2004. Below are the distances of the Olympic individual road race since 1984, the first year women were included. I collected the data from different sources - surprisingly there doesn’t appear to be a single source that has consistent records of distances and times over that period (not even Wikipedia!). Of course, to better understand the data one should also consider how much climbing was involved.

Distances Olympic individual road race, 1984-2012

The absolute difference hasn’t changed much: men ride about 110 km more than women. The relative difference has decreased substantially: until 1992, the distance for men was 2.4 times the distance for women; by 2012 that factor had shrunk to 1.8. So this confirms that distances are converging. Of course, the distance women race is still shorter than most Tour stages.

In a slightly cryptic article, it has been argued that the distances for women must be shorter than those for men: otherwise women’s speed would drop and they wouldn’t be able to display their technical skills («corner, change direction, or maintain their trajectory while looking at their opponents») optimally. So is women’s speed dropping as Olympic races become longer?

Average speed of winner Olympic individual road race, 1984-2012

The graph above shows the average speed of the winners of the Olympic road races since 1984. While the difference between men and women has somewhat increased, it’s not the case that women’s speed has dropped. On the contrary, the winner of 2012 was 8% faster than the winner of 1984 (over a distance that was two-thirds longer).

In short, I can see no particular reason why women riders shouldn’t get the chance to prove themselves in the 2014 Tour de France.

Graphs may not display in older versions of Internet Explorer.

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OV-fiets gaat live informatie bieden over beschikbaarheid huurfietsen

Alle data & grafieken-geeks retweeten momenteel een kaart die laat zien op welke locaties er nog goedkope huurfietsen beschikbaar zijn bij populaire projecten als Vélib’ in Parijs, Bicing in Barcelona en Citi Bike in New York. De maker van de kaart, Ramnath Vaidyanathan, heeft voor honderd bike sharing-projecten de beschikbaarheid van huurfietsen in kaart gebracht. Dat betekent in de eerste plaats dat er dus al honderd van dit soort projecten zijn en in de tweede plaats dat al die projecten actuele gegevens aanbieden over de beschikbaarheid van huurfietsen (via een API).

Nederland komt in het lijstje niet voor. Ondanks het feit dat het Amsterdamse witte fietsenplan vaak als inspiratie wordt genoemd voor dit soort projecten, hebben wij zelf geen echt bike sharing-project (lees hier waarom). Wel hebben we de OV-fiets, maar die biedt weer geen actuele informatie over de beschikbaarheid van huurfietsen. Althans, nog niet. Een woordvoerder van de NS laat desgevraagd weten dat er momenteel aanpassingen worden gedaan aan de ICT waardoor «in de nabije toekomst» wel actuele informatie over de beschikbaarheid van OV-fietsen kan worden geboden. Dat is goed nieuws.

Overigens is het mij nog niet vaak overkomen dat de OV-fietsen op waren. De Fietsersbond heeft een aantal keer onderzoek gedaan naar de OV-fiets. In 2011 was de beschikbaarheid nog het belangrijkste probleem volgens respondenten; in 2013 was dat niet langer het geval. De NS zegt constant in de gaten te houden of er voldoende fietsen beschikbaar zijn en zonodig bij te sturen.

Summary: 

Ramnath Vaidyanathan has mapped the availability of bikes in bike sharing programmes across the world. Although the Dutch ‘White Bicycle’ plan is often cited as inspiration for such initiatives, there’s no ‘real’ bike sharing programme in the Netherlands (read why). Dutch Railways does offer OV-fiets rental bikes (note that the OV-fiets may not be easily available to tourists), but doesn’t have an API that provides realtime data on the availability of bikes. That is, not yet: when I asked Dutch Railways about their plans, a spokesperson indicated that this data will be made available ‘in the near future’.

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