
Southern Districts BMX Raceway
Cnr Tucker and Atkinson St Medina WA 6167 - Southerndistrictsbmx@gmail.com
BMX Bicycle Frame Size Chart
* These are only suggestions for BMX Racing and may differ to individual riders*
Rider Height Frame Size Stem Length Bar Rise Bar Width
4' - 4' 6" Mini Mini XL, Mini 2" - 3" 21" - 23"
4'4" - 4'10" Junior Mini XL - Pro 3" - 5" 22" - 25"
4'8" - 5'4" Expert Pro 5" - 7" 25" - 27"
5'4" - 5'10" Pro Pro - Pro XL
Pro XL Pro XL 7" - 8" 27" - 28"
5'10" + Pro XL- XXL Pro Xl - XXL 7" - 8" 28"
CRANK LENGTH AND RECOMMENDED GEARS
Inseem Crank Length Gearing Range Gearing Range
inches millimeters
19 to 21 135
20 to 22 140
21 to 23 145
22 to 24 150 41 42 43 /16
23 to 25 155 41 42 43 /16
24 to 26 160 41 42 43 /16 42 or 43 /16
25 to 27 162 41 42 43 /16 42 or 43 /16
26 to 28 165 41 42 43 /16 42 or 43 /16
27 to 29 170 42 or 43 /16
28 to 30 175 42 or 43 /16 43 or 44 / 16
29 to 31 177 43 or 44 / 16
30 to 33 180 43 or 44 / 16 44 / 16 up
31 to 34 182 44 / 16 up
32 to 35 185 44 / 16 up
33 to 36 185 44 / 16 up
34 plus 190 44 / 16 up
Recommended Gearing
Tyres Chainring Driver Tyres Chainring Driver
20 x 1.75 38 39 40 14 24 x 1.75 34 35 36 15
41 42 43 15 36 37 38 16
44 45 46 16 38 39 40 41 17
40 41 42 43 18
20 x 1.5 38 39 40 41 14
41 42 43 44 15 24 x 1.5 34 35 36 37 15
44 45 46 16 37 38 39 16
39 40 41 42 17
20 x 1 3/8 35 36 37 14 41 42 43 44 18
37 38 39 40 15
39 40 41 42 16 24 x 1 3/8 34 35 15
37 38 39 40 16
20 x 1 1/8 35 36 37 38 14 39 40 41 42 17
37 38 39 40 15 41 42 43 44 18
40 41 42 43 16
24 x 1 1/8 35 36 37 15
37 38 39 16
39 40 41 17
41 42 43 18