Context I noted this data because there are several sites that claim to supply it, but either there are small unexplained discrepancies with the official data, or the data is misrepresented as the winner's average speed rather than the overall average speed. Content This is a small .csv set originally made as a googlesheet. It lists the average speed of the Tour de France each year from 1903 to 2018 and was created (May 2019) using the speeds given on the Tour de France website. Each speed is noted to three decimal places and has been doublechecked. There are two gaps in the data: the years around WWI and WWII when the race was not held. Inspiration I noted this data because I wanted to answer the question 'Is the Tour slowing down? (now that it's 'cleaner'). I wrote up a graph here: https://medium.com/@aidan.odonnell/is-the-tour-de-france-slowing-down-and-if-not-why-not-bf32ce46c06b