Higher up the Tremola, the hairpins lose their trees. The old Gotthard road climbs out of the last of the stunted spruce and into bare granite and tussock grass, and the walls that hold up the bends rise in neat steps, one above another, with the tiny shapes of other riders and walkers moving along them. This is the part of the road that appears on postcards, and it deserves it. From a bend near the top you can look straight down on three or four hairpins at once, laid out like the folds of a ribbon.
The granite here is the heart of the Alps. The Gotthard massif is made of some of the oldest and hardest rock in Switzerland, and the road builders had to cut and blast it by hand, then fit the setts one by one. You can see the quality of the work in the walls, in the neat drainage channels and in the cobbles themselves, which have survived nearly two centuries of coaches, cars and weather with only occasional repairs. Rock fall and frost still do damage, and each spring the road crews check for loose stones before opening.
Riding the upper section is easier than the lower, because the corners are a little more open and the rhythm builds, but the exposure is greater. The wall is low, the drop is real and the wind can arrive suddenly, catching a rider on the bend. The surface is rough, with gaps between the stones where water collects, and a cold morning can leave patches of ice into June. A relaxed grip, a steady throttle and a wide smile at the camera pointed at you from above are the right approach.
The air at this altitude is thin and fresh, smelling of stone, damp moss and the faint sweetness of alpine plants. Marmots whistle from the rocks, and in the evening the light turns the granite pink. Clouds can come down fast, bringing rain, sleet or snow, and temperatures can drop by ten degrees in an hour. A waterproof layer and warm gloves are sensible, even in July.
Airolo, about four kilometres below, is the nearest village with services, and Altdorf, on the other side of the pass, is the larger town. The summit has a restaurant and a museum, a short ride higher, and a hot chocolate there tastes better than it has any right to.