By rights, 4x is a mountian bike dicipline, therefore you are required to have at least 24 inch wheels and five working gears, so bmx and cruisers are not allowed.Ty said:ok heres one that some people disagree with, make it rough enough that it would be slower to do on a BMX, i reckon you could get around Lobb street and the Mogil track quicker on a 20 inch, make something that forces you over rougher ground that mountain bikes are designed to ride over.
Fair enough comment though because in reality you will get weekend riders use the track on BMX and cruisers.