CAR GEARING
Gear ratio calculator, pinion/spur, speed estimate
GEAR RATIO CALCULATOR
FINAL DRIVE RATIO
Spur Gear Teeth
Pinion Gear Teeth
Internal Ratio
Motor KV
Battery Voltage (V)
Wheel Diameter (mm)
Top speed estimated at 80% of no-load motor RPM (load factor). Actual speed depends on traction, weight, and motor efficiency. Wheel diameter should include tyre.
GEARING GUIDE
| SITUATION | ADJUSTMENT | EFFECT |
|---|---|---|
| Motor runs hot | Reduce pinion (smaller) OR increase spur | Reduces load. Slower top speed, cooler motor. |
| ESC runs hot | Reduce pinion or check motor timing | Reduces current draw. |
| Want more top speed | Increase pinion (larger) OR reduce spur | Higher FDR. More load on motor. |
| Want more acceleration | Reduce pinion OR increase spur | Lower FDR. Better punch off the line. |
| Racing on a tight track | Run lower gearing (smaller pinion) | Better mid-range torque and acceleration. |
| Long straight track | Run higher gearing (larger pinion) | Higher top speed. Motor must cope with heat. |