Dodging speeding cars, crazed cabbies, open doors, and eight million cranky pedestrians is all in a day's work for Wilee, the best of New York's agile and aggressive bicycle messengers. It takes a special breed to ride the fixie -- super lightweight, single-gear bikes with no brakes and riders who are equal part skilled cyclists and suicidal nutcases who risk becoming a smear on the pavement every time they head into traffic.