I've had branches and tree limbs flip up from my front tires and smack my hands, not fun. Back in March I was riding with my friend, and I was a good 4-6 bike lengths behind him, playing tag, and I watched a large piece of blue stone shoot out from his back tire at me, with no time to react. Luckily it somehow hit my brake lever! After that I hunted down a set of direct fit moose handgaurds. Never liked the gaurds with the aluminum rail, prefer the all plastics units that wont pin your hand in an accident.