WHAT THE FOOK????fit in little gaps??r u a crakhead what the fook does that mean???you should get the siz of bike you feel right on.If you know any trials riders have a go on there bikes and decide which wheel size you like better and stick with that. also it depends on how tall you are but i would reccomend a mod(20") to start on as they are more flicky and more easier to handle.then when you get a stock you will benitfit a lot from having ridden a mod beforehand Tom