Ya Sam's bike is a small, Brendan is a large one, theres a pretty big difference, take a look a few comments up, Downhilldustin posted a small and a large, you'll see the difference
just the colour of it i think, cant really see brendans link as well but it's the same. my attention was drawn to the gnarly pins on brendans bike though! you can tell they'd tear you to pieces from miles off! haha