BMX Race Bikes
Brief summary of BMX race bike sizes
These are for the smallest of riders - 4 or 5 year olds. These will sometimes have 20x1 1/8 wheels but usually 18x1. These bikes
are made to be as small and light as possible. Crank length is typically about 130mm
Typical wheel size is 20x 1 1/8. Crank lengths around 150mm and sized for average 5 to 7 year olds.
Wheels are the same as Minis but usually have a fatter tire - 20x1 3/8. Cranks are about 160mm in length and overall sizing
suitable for 7 to 9 year olds.
Some experts have 20x1.5 wheels/tires while others have 20x1 3/8 - these are 2 completely different wheel sizes with the 20x1.5 wheel size allowing for use of
fatter tires like 20x1.75 up to 20x2.25. Anyways... Experts are usually sized for 9 to 12 year olds - with subcategories of of expert XLs - basically sized for
tall skinny young riders. Cranks are usually 170mm.
Pro, XL, XXL
Basically once you reach the pro sized bikes and bigger, you're catering to strong, powerful riders - just of different sizes. The biggest difference in
size is the length of the frame's top-tube. Pros are usually about 20" top tube, about 21" for XL then add 1/4" to 1/2" for each size increase. All these
changes and interpretations of rider needs differ from one brand to the next.