Most Pro BMX'rs Run Approximately 54 gear inches ( this is the high-lighted area in each chart)
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)
| 20" X 1.75" GEAR CHART (19.5" tire diameter) = any size rider |
| CHAIN WHEELS | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| Rear Gear 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 |
| Rear 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 |
| Rear 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 |
| 20" X 1.50" GEAR CHART (19" tire diameter) = riders under 150lbs |
| CHAIN WHEELS | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| Rear Gear 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 |
| Rear 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 |
| Rear 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 |
| 20" X 1.375"(1 3/8) GEAR CHART (21" tire diameter) = riders under 120lbs |
| CHAIN WHEELS | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| Rear Gear 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 |
| Rear 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 |
| Rear 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 |
| 20" X 1.125"(1 1/8) GEAR CHART (20" tire diameter ) = riders under 80lbs |
| CHAIN WHEELS | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| Rear Gear 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 |
| Rear 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 |
| Rear 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 |
| 24" X 1.75" GEAR CHART (23.5" tire diameter) = any size rider |
| CHAIN WHEELS | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| Rear Gear 15 | 53.2 | 54.8 | 56.4 | 58.0 | 59.5 | 61.1 | 62.6 | | | | | | |
| Rear 16 | 49.9 | 51.4 | 52.8 | 54.3 | 55.8 | 57.3 | 58.5 | 60.2 | 61.6 | 63.1 | | | |
| Rear 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 | |
| Rear 18 | | | | 48.3 | 49.6 | 50.9 | 52.2 | 53.5 | 54.8 | 56.1 | 57.4 | 58.7 | 60.0 |
| 24" X 1.50" GEAR CHART (23" tire diameter) = riders under 150lbs |
| CHAIN WHEELS | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| Rear Gear 15 | 52.1 | 53.7 | 55.2 | 56.7 | 58.2 | 59.8 | 61.3 | 62.8 | 64.4 | 65.9 | 67.4 | 69.0 | 70.6 |
| Rear 16 | 48.4 | 50.3 | 51.8 | 53.2 | 54.6 | 56.0 | 57.5 | 58.9 | 60.3 | 61.8 | 63.2 | 64.6 | 66.2 |
| Rear 17 | 46.0 | 47.3 | 48.7 | 50.0 | 51.4 | 52.8 | 54.1 | 55.5 | 56.8 | 58.8 | 59.5 | 60.8 | 62.3 |
| Rear 18 | 43.4 | 44.7 | 46.0 | 47.2 | 48.5 | 49.8 | 51.1 | 52.4 | 53.7 | 54.9 | 56.2 | 57.5 | 58.9 |
| 24" X 1.375" (1 3/8") GEAR CHART (24" tire diameter) = riders under 120lbs |
| CHAIN WHEELS | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| Rear Gear 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 |
| Rear 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 |
| Rear 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 |
| Rear 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 |
| 24" X 1.125" (1 1/8") GEAR CHART (22.6" tire diameter) = riders under 80lbs |
| CHAIN WHEELS | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 |
| Rear Gear 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 |
| Rear 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 |
| Rear 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 |
| Rear 18 | 42.7 | 43.9 | 45.2 | 46.6 | 47.7 | 49.1 | 50.3 | 51.5 | 52.8 | 54.0 | 55.3 | 56.6 | 57.9 |