The drop-off in 1964 compared to 1963 was so large and the trend so much more flat that it took eight years to make up the decline. That reversed with the 1964 Tour when, for the second time, the win-ning speed significantly declined. The rate of increase from 1947 through 1963 was less than the post-WW1 trend, the speeds were more variable, and there were many instances of lower speeds than a preceding race. The 1947 Tour was won at almost the same speed as the 1939 race and the pre-WW2 trend of faster winning speeds continued.

Jean Alavoine, third-place in the 1909 Tour de France with a bike of the era The trend (represented by the line through the data points) for the decade before WW2 marks it as the period during which Tour speed increased at a faster rate than at any time in the history of the event, as the steepness of the slope demon-strates. The winning speed of the 1927 Tour spiked up almost 10 percent, and continually increased for the next twelve years. Tour speeds were slower but consistent when racing resumed in 1919, averaging a bit more than 24 kph for the next ten years. The next few were faster, with winning speeds of 28 to 29 kph, while the last four held before WW1 finished with measurably lower average speeds – though faster than the earliest races. The earliest were completed at about 25 kph. The first dozen races (to 1914) produced no trend in the winning speed. Throughout the essay, I refer to them as slopes, lines, rates of increase, and trends interchangeably. The following figure highlights interesting irregularities in that trend.Īll of the lines in the figure above are calculated ordinary least squares estimates (“regression slopes”).

He kindly agreed to share his thoughts in the following essay:Įvery cyclist who pays attention to the Tour de France knows that speeds have increased over the 112-year history of the race.

Petrocik, the author of the following piece, sent me a fascinating note summerizing his observations about the increases in the average speeds of the Tour de France over the last century. Racing at Increasing Speed by John R Petrocik

Bicycle average speed