What is final drive ratio in an RC car?
Final drive ratio is the total motor-to-wheel reduction after the spur, pinion, and internal drivetrain ratio are combined.
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Setup reference
What this calculator does
Enter the drivetrain ratios and tire diameter to turn tooth counts into final drive, rollout, and an unloaded wheel RPM estimate. Use it before changing gearing so the mechanical difference is clear.
FAQ
RC setup questions
What is RC rollout?
Rollout is the distance the car travels for one wheel revolution. It combines tire diameter and final drive ratio into one setup number.
Does a smaller pinion increase final drive ratio?
Yes. With the same spur gear and internal ratio, a smaller pinion increases reduction and lowers wheel speed.