Update of the Alpe d'Huez climbing times and speed chart previously posted here and here. Read those previous posts for discussion of context.
Edit (28 July 2015): since posting this two days ago, I was alerted to some updates made to the 1991 ascent times. Two sources did work with archive video to better verify these times, the net result being an addition of 41 seconds to each of the 1991 ascent times.
Thanks to https://twitter.com/ammattipyoraily for the posting the data.
This chart shows the average speed of the five fastest ascents up the Alpe d'Huez climb for each year the Tour de France included this climb, with the exception being the times from the 1980s which are the average speeds for fewer riders (as data on five fastest ascents in those years is not available to me).
|Weather data source: http://www.wunderground.com/|
Course profile shows the climb is not a constant gradient:
and here are the fastest 5 riders by year (click to see larger version), with lines marking the time of the 50th and 100th fastest ascents of all time: