Bro
a Bro or flatbiller is usually a guy between the age of 18 and 30 who devotes their life and lifestyle to Motocross and/or skating. Typically wears black shirts and hats, ie. Fox Racing, Skin, Metal Mulisha, Alpinestars, No Fear, and Famous.  They Listen to mostly hessian rock, Metallica, Slayer, NOFX, some old punk and new popular rap. Drive either a Jacked up Truck, usually a chevy, or ford. new and old alike, with huge tires mud and street tires. some even drive lowriders or an old "rat rod". Rides bikes with their other bro's. drinks beer, smokes pot, and always get in fights with their girlfriends. Are complimented with badass tattoos, and use the word badass alot. there are good and bad in the like. as well as every class. 
Yo whats up Bro! thats a badass truck dog, lets go get the bikes and pickup some squares and beer and go cruise the strip.