Rider Size and Bike Frame Guidelines
Rider Height |
Frame Size |
Top Tube |
Stem |
Bar Rise |
Bar Width |
Cranks |
Gearing |
4'0"& under |
Micro-Mini |
15"-16" |
Mini |
2"-2.5" |
20"-22.5" |
135-140mm |
41-43/16 |
4'0"-4'6" |
Mini |
16"-17" |
Mini-Mini XL |
2"-3.5" |
21"-23.5" |
140-155mm |
41-43/16 |
4'4"-4'10" |
Junior |
17"-18.5" |
Mini XL-Pro |
3"-5" |
22"-25" |
155-170mm |
42-43/16 |
4'8"-5'4" |
Expert |
18.5"-19.5" |
Pro |
5"-7" |
25.5"-27" |
165-175mm |
42-43/16 |
5'4"-5'10" |
Pro |
20"-20.5" |
Pro-Pro XL |
7"-8" |
27"-28" |
175-180mm |
43-44/16 |
5'10"& over |
Pro XL-XXL |
20.5"& over |
Pro XL-XXL |
7"-8" |
28.5" (max) |
175-185mm |
44/16&over |
Crank Length Guidelines
Riders Inseam |
20" |
21" |
22" |
23" |
24" |
25" |
26" |
Crank Length |
140mm |
145mm |
150mm |
155mm |
160mm |
162mm |
166mm |
Riders Inseam |
27" |
28" |
29" |
30" |
31" |
32" |
34" |
Crank Length |
171mm |
175mm |
177mm |
180mm |
182mm |
185mm |
190mm |
Wheel Size for Rider Weight Guidelines
Max Rider Weight |
Rim Width |
Up to 65 lbs |
Sew Ups |
50 to 90 lbs |
1 1/8" |
85 to 120 lbs |
1 3/8" |
115 to 150 lbs |
1.50" |
140 lbs and Up |
1.75" |
Most Pro BMX'rs Run Approximately 54 gear inches
44/16 gear ratio with 20x1.75 tire is the most commonly used combination in BMX
For Exact Gear Measurement... Divide Front Gear by Rear Gear and Multiply by Tire Diameter
Example: 44/16 = 2.75 x 19.5 = 53.625 gear inches (20x1.75 tire)
these charts are for general reference - actual tire diameter varies from brand to brand
| Freewheel 14 | 47.4 | 48.7 | 50.2 | 51.6 | 53.0 | 54.4 | 55.7 | 57.1 | 58.5 | 59.9 | 61.9 | 62.7 | 64.1 |
| Freewheel 15 | 44.2 | 45.5 | 46.8 | 48.1 | 49.4 | 50.7 | 52.0 | 53.3 | 54.6 | 55.9 | 57.2 | 58.5 | 59.8 |
| Freewheel 16 | 41.4 | 42.7 | 43.9 | 45.1 | 46.3 | 47.5 | 48.8 | 50.0 | 51.2 | 52.4 | 53.6 | 54.9 | 56.1 |
| Freewheel 14 | 46.8 | 48.1 | 49.5 | 50.9 | 52.3 | 53.6 | 55.0 | 56.4 | 57.5 | 59.1 | 60.5 | 61.8 | 63.2 |
| Freewheel 15 | 43.6 | 44.9 | 46.2 | 47.4 | 48.8 | 50.1 | 51.3 | 52.8 | 53.9 | 55.2 | 56.5 | 57.7 | 59.1 |
| Freewheel 16 | 40.9 | 42.1 | 43.3 | 44.5 | 45.7 | 46.9 | 48.1 | 49.3 | 50.5 | 51.7 | 52.9 | 54.1 | 55.3 |
| Freewheel 14 | 51.0 | 52.5 | 54.0 | 55.5 | 57.0 | 58.5 | 60.0 | 61.5 | 63.0 | 64.5 | 66.0 | 67.5 | 69.0 |
| Freewheel 15 | 47.6 | 49.0 | 50.4 | 51.6 | 53.2 | 54.6 | 56.0 | 57.4 | 58.8 | 60.2 | 61.6 | 63.0 | 64.4 |
| Freewheel 16 | 44.6 | 45.9 | 47.3 | 48.6 | 49.9 | 51.2 | 52.5 | 53.9 | 55.2 | 56.5 | 57.8 | 59.1 | 60.4 |
| Freewheel 14 | 48.6 | 50.0 | 51.4 | 52.8 | 54.3 | 55.7 | 57.1 | 58.6 | 60.0 | 61.4 | 62.8 | 64.3 | 65.7 |
| Freewheel 15 | 45.3 | 46.7 | 48.0 | 49.3 | 50.7 | 52.0 | 53.3 | 54.7 | 56.0 | 57.3 | 58.7 | 60.0 | 61.3 |
| Freewheel 16 | 42.5 | 43.8 | 45.0 | 46.2 | 47.5 | 48.7 | 50.0 | 51.2 | 52.5 | 53.7 | 55.0 | 56.2 | 57.5 |
| Freewheel 15 | 53.2 | 54.8 | 56.4 | 58.0 | 59.5 | 61.1 | 62.6 | ||||||
| Freewheel 16 | 49.9 | 51.4 | 52.8 | 54.3 | 55.8 | 57.3 | 58.5 | 60.2 | 61.6 | 63.1 | |||
| Freewheel 17 | 47.0 | 48.4 | 49.7 | 51.1 | 52.5 | 54.0 | 55.3 | 56.6 | 58.2 | 59.4 | 60.8 | 62.2 | |
| Freewheel 18 | 48.3 | 49.6 | 50.9 | 52.2 | 53.5 | 54.8 | 56.1 | 57.4 | 58.7 | 60.0 | |||
| Freewheel 15 | 54.4 | 56.0 | 57.6 | 59.3 | 60.7 | 62.4 | 64.1 | 65.5 | 67.2 | 68.9 | 71.3 | 72.0 | 73.7 |
| Freewheel 16 | 51.1 | 52.5 | 54.0 | 55.5 | 57.0 | 58.5 | 60.0 | 61.4 | 63.1 | 64.5 | 66.0 | 67.4 | 69.1 |
| Freewheel 17 | 48.0 | 49.4 | 50.8 | 52.2 | 53.6 | 55.1 | 56.5 | 57.9 | 59.3 | 60.7 | 62.1 | 63.3 | 65.0 |
| Freewheel 18 | 45.3 | 46.5 | 48.0 | 49.4 | 50.7 | 52.0 | 53.3 | 54.7 | 56.0 | 57.3 | 58.5 | 60.0 | 61.4 |
| Freewheel 15 | 51.3 | 52.8 | 54.3 | 55.8 | 57.3 | 58.8 | 60.3 | 61.8 | 63.3 | 64.9 | 66.3 | 67.9 | 69.4 |
| Freewheel 16 | 48.1 | 49.5 | 50.9 | 52.3 | 53.7 | 55.1 | 56.6 | 57.9 | 59.5 | 60.8 | 62.2 | 63.9 | 65.1 |
| Freewheel 17 | 45.2 | 46.6 | 47.9 | 49.3 | 50.6 | 51.9 | 53.2 | 54.6 | 55.9 | 57.2 | 58.6 | 59.9 | 61.3 |
| Freewheel 18 | 42.7 | 43.9 | 45.2 | 46.6 | 47.7 | 49.1 | 50.3 | 51.5 | 52.8 | 54.1 | 55.3 | ||