Estimating torque and power requirements is a useful early step when selecting a brushless hub motor for mobile equipment. Company’s guide uses three key inputs—fully loaded weight, target speed, and maximum climbing gradient—to help buyers develop an initial requirement. The result is an estimate for evaluation, not a substitute for checking a motor’s specifications and operating limits.

Start with the operating requirements

Use values that represent the intended operating condition. The fully loaded mass should include the equipment, payload, and any other weight carried during operation. Define the target speed for the climb and the steepest gradient the equipment is expected to handle.

• Fully loaded mass: the total operating mass, in kilograms (kg).
• Target speed: the required climbing speed, in metres per second (m/s). To convert kilometres per hour to metres per second, divide by 3.6.
• Maximum climbing gradient: express the gradient as a decimal for the calculations below. For example, a percentage value is divided by 100 before use.

Estimate climbing force, wheel torque, and power

For a steady-speed climb, the basic estimate starts with the force required to overcome gravity on the slope. This provides a grade-only baseline; other forces may also affect the actual requirement.

Account for real operating conditions

The grade-only calculation does not include every force acting on mobile equipment. Rolling resistance, acceleration, surface conditions, tyre characteristics, and load distribution can change the torque and power required.

• Rolling resistance: include it when a suitable resistance value for the wheel and operating surface is available.
• Acceleration: add the force required for the intended acceleration if the equipment must speed up while climbing.
• Motor and system losses: if converting wheel power into a motor power requirement, account for efficiency using a value appropriate to the motor and system. Do not assume an efficiency value without supporting information.

Where these factors are not yet known, treat the grade-only result as a preliminary baseline and identify the missing inputs before final motor selection.

Use the estimate to narrow motor requirements

1. Calculate the force needed for the maximum climbing gradient at the specified fully loaded mass.
2. Use the driven wheel radius to estimate total wheel torque, then account for the number of driven motors and the actual load distribution.
3. Calculate power at the target speed using the total tractive force. Include additional resistance or acceleration forces when relevant data is available.
4. Compare the resulting requirements with the motor’s available torque and power at the intended operating speed, voltage, and duty conditions.

A practical selection check

A calculated torque or power value is only useful when compared with specifications defined for the same operating conditions. Confirm how the manufacturer states rated power, rated rotating speed, rated current, and theoretical torque, and check any applicable environmental requirements. If the required operating point is unclear, provide the load, speed, gradient, wheel radius, drive configuration, and duty conditions when discussing motor options with Company.

What this estimate can—and cannot—tell you

This method helps mobile equipment buyers organize key inputs and create an initial torque and power estimate for brushless hub motor evaluation. It does not identify a specific motor or establish a guaranteed climbing capability. Final selection depends on the complete application requirements and verified motor performance information.