Frame Sizes

BMX frame sizes are pretty much standardised across the industry.

A junior model of one brand is pretty much like a Junior model of another brand. As you might expect, your ideal bike size depends on the size of your body. This chart shows some common rider/bike sizes.

Riders Height / Bike Size
4’0” and under / Micro Mini
4’0” – 4’6” / Mini
4’6” – 4’10” / Junior
4’8” – 5’4” / Expert
5’4” – 5’10” / Pro
5’8” – 6’0” / Pro XL
6’0” + / Pro XXL

Cranks

Your ideal crank is the longest you can spin quickly and smoothly

Riders Height / Bike Size / Crank Length (mm)
4’0” and under / Micro Mini / 150 - 160
4’0” – 4’6” / Mini / 155 - 165
4’6” – 4’10” / Junior / 160 - 175
4’8” – 5’4” / Expert / 170 - 175
5’4” – 5’10” / Pro / 175 - 180
5’8” – 6’0” / Pro XL / 180 - 185
6’0” + / Pro XXL / 180 - 185

Handle Bars

Try the push up test

Get a tape measure, set it on the ground, do 100 push ups. OK, OK ..... 10 will do. Measure the distance between the edges of your hands. That’s your position of maximum strength, and it is usually a good handlebar width.

Riders Height / Bike Size / Bar Rise / Bar Width
4’0” and under / Micro Mini / 2” - 2.5” / 20” - 22.5”
4’0” – 4’6” / Mini / 2” - 3” / 21” - 23.5”
4’6” – 4’10” / Junior / 3” - 5” / 22” - 25”
4’8” – 5’4” / Expert / 5” - 7” / 25.5” - 27”
5’4” – 5’10” / Pro / 7” - 8” / 27” - 28”
5’8” – 6’0” / Pro XL / 7” - 8” / 28”
6’0” + / Pro XXL / 7” - 8” / 28”

Stems

If you need to change your stem length by more than 10 mm, you might need to change your frame size

Riders Height / Stem Size / Length (mm)
4’6” & under / Mini / 20 – 35 mm
4’6” – 4’10” / Mini XL/Expert / 35 – 45 mm
4’10” – 5’10” / Pro / 50 – 55 mm
5’10” & over / Pro XL/XXL / 55 – 60 mm