I want a bicycle that I can do skids with. Im looking at a 700c Kent Mens RoadTech Roadbike but Im not sure if a fixed gear bicycle is required for doing skids. I understand it's alot easier to do skids with a fixed gear bicycle, but can I do this with a 21 speed? One more question I have is how long will a tire last if I do around 10 skids a day?