Rubbie is an Acronym for Rich Urban Biker. It is a term used to identify people who have no business riding a motorcycle. The "Weekend Warrior." Rubbies are usually riding very expensive stock motorcycles and wear a lot of leather. A Rubbie would also be the type of person whose first motorcycle was a custom "chopper" built for them by a place like Orange County Chopper. Rubbies typically are unable to do even the most simple maintenance of their motorcycles and take them to dealerships to be repaired. In essence, Rubbies are posers.
Look at that Rubbie with the Forty thousand dollar bike. He had to have his bike towed to the dealership to change the battery.