The land flattened out as we pedaled toward the mountains, which loomed ahead like the broken jawbone of an old skull. Almond groves lined the roadway, and the windblown trees, leafing out and nearly shed of their blossoms, leaned away from the mountains at a sharp angle, as if cowering at the sight of the peaks.

In our first two days of cycling through Mallorca, we’d endured nothing more strenuous than a few rolling hills, just enough of a challenge to complement the picture-perfect landscape and the food and wine that this Spanish island offers in abundance. But with the Serra de Tramuntana now upon us—the range that brings world-class cyclists to this island from around the globe—that was about to change…