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.

Portland is arguably the furthest along of any American city as far as far as bicycle-friendly infrastructure goes (Seattle and Davis are close seconds). But none of them even approaches the level of cultural saturation prevalent in the Netherlands; the grand Mecca of cycle commuting. That is not to imply the American cities' efforts are futile, I mention the disparity only to convey the weight behind a statement this week from the Dutch Cycling Federation calling on the government to mandate the installation of air bags on cars. On the outside.

Cycle your way out of traffic jams and high fuel costs-without breaking a sweat. Simply slide a canister of gasoline into your water-bottle holder, clip a throttle to your handlebars, and swap your front wheel for the Wheel, designed by Denver-based RevoPower (revopower.com). The Wheel´s hub holds a 23cc, two-stroke internal combustion engine and a superthin gear train; less than three inches thick, it all fits between the prongs of your bike´s front fork.