Hoodbombing n.

Riding a (generally itty-bitty) bike as fast as possible, often in a pack, down the steep, five-and-a-half-mile stretch of Timberline Road between Timberline Lodge and US 26. Occasionally results in serious injury, as happened in August when a cyclist lost control, smashed into a concrete barricade, and skidded 40 feet.
See also: zoobombing, Life Flight, Darwin Awards.