The sting in the tail

There is a particular betrayal in a climb that starts kindly. You settle into a rhythm you think you can hold all the way to the top, and somewhere past halfway the road stands up and takes it off you. Two climbs can both average seven per cent: one holds seven the whole way, and the other gives you five for half an hour before turning into nine when there is nothing left to give it.

Rocacorba is the cruellest of them: a gentle opening through the woods, then a middle section that simply keeps hurting all the way to the top. The Stelvio is generous out of Prato for eight or ten kilometres before it steepens and stays steep. Pikes Peak saves its worst for above the treeline, where the air has stopped helping.

Alpe d'Huez, for all its reputation, does the opposite. The hard part comes early and the last few virages are a run-in. Knowing which kind of climb you are on changes how you ride the first hour of it.