Cyclists and Slopes
When I first starting paying attention to the Tour de France, I assumed that the mountain climbs must be at least at 30˚ . Here is the reality. Even a 6˚ slope is considered brutal. This translates to roughly a 10% grade. The following table provides estimates of how to classify various slopes/grades.
Alp d’Huez Difficulty
I had a Trek bike model Alp d”Huez. So I have always had an interest in that particular climb. ClimbByBike is a group that arranges for cyclists to make climbs around the world and their .com website has detail portrayals of the individual climbs including the Alpe d’Huez. Their data gives gradients down to a 0.5 km or 0.31 miles. Their data indicates an average gradient of 8.1% over the complete ride, and a max gradient over their segments of 10.6%. Looking at the VeloView data which is even more granualar, they have one stretch at the start of 13.7% for 43 meters or 0141 feet, and another near the end of 14.9% for 7 meters or 23 feet.
What is the worst Tour de France climb?
Surprisingly, it is not even in France but in England where the Tour actually begins.
The brutal fact is the picture lies. It is encountered in Sheffield England and is a 33% or 18.78˚ climb of 800 m.