To power up a mountain, you need a stiff bike frame that transfers pedaling force straight to the wheels. But zooming downhill without jolts or spills calls for more cushioning. So Kona’s Coilair bikes feature a lever that automatically shortens the shock when you pedal and lengthens it when you coast. The lever also pushes the seat closer to the ground, lowering the center of gravity to match the stability of a dedicated downhill racing bike.

At the starting dock of the Olympic triathlon trials, the expression on Andy Potts’s face seems to say I will kill you with my eyes. As the starting gun fires, he plunges into the Black Warrior River in Tuscaloosa, Alabama, and, in a burst of white foam, quickly pulls ahead of nine rivals. The second-ranked Hunter Kemper manages to hold pace with Potts for a few minutes, then drifts back into third place.