Lycra Lout
Adjective: A collective term that has come into being to describe those who, more often than not clad in figure-hugging brightly coloured stretchy materials, flout road laws and common sense, by riding their bikes on public roads (and pavements/side walks) without any consideration for other road users and/or pedestrians.
Examples of Lycra Lout behaviour include running red lights (both road junction and pedestrian crossing points), vulgar gestures and language to almost anyone who gets in their way, and sometimes even unwarranted and unprovoked violent behaviour towards anyone having the gall to question their actions (esp. pedestrians and motorists).