ok so i was googling sum stuff and i guess i can google sum more but i figured id ask here first just for shits and giggles lol..what is the difference BESIDES tire size? like is the 'rb' just cuz from stock it comes with a bigger tire? can i make mine an 'expert' by simply changing the tire size? and if i did change tire size what else would i need to adjust? (sprockets? suspension? or can i leave these the same size)