Home
Back
Motorcycle Power Conversion Formula:
| From: | To: |
The motorcycle crank HP to wheel HP conversion calculates the actual power delivered to the rear wheel after accounting for drivetrain losses. This conversion is essential for understanding real-world performance and dyno measurements.
The calculator uses the motorcycle power conversion formula:
Where:
Explanation: Motorcycles typically lose about 5% of their crankshaft power through the transmission, chain/belt drive, and other mechanical components before reaching the rear wheel.
Details: Understanding the difference between crank HP and wheel HP is crucial for performance tuning, dyno testing, and realistic performance expectations. Wheel HP represents the actual power available for acceleration and top speed.
Tips: Enter the manufacturer's claimed crankshaft horsepower. The calculator will provide the estimated wheel horsepower after typical drivetrain losses. Values must be positive numbers.
Q1: Why is there a difference between crank HP and wheel HP?
A: Power loss occurs through friction in the transmission, clutch, and final drive components (chain, belt, or shaft), resulting in wheel HP being lower than crank HP.
Q2: Is 95% efficiency accurate for all motorcycles?
A: While 95% is a good average, efficiency can vary between 90-97% depending on the drivetrain type, maintenance, and motorcycle design.
Q3: Which drivetrain type is most efficient?
A: Chain drives are typically most efficient (94-97%), followed by belt drives (92-95%), with shaft drives being least efficient (88-92%) due to additional gear reduction.
Q4: How accurate are manufacturer HP claims?
A: Manufacturer claims are usually crankshaft HP measured under ideal conditions. Real-world wheel HP is what actually propels the motorcycle.
Q5: Can modifications affect drivetrain efficiency?
A: Yes, proper chain tension, quality lubricants, and well-maintained components can maximize efficiency, while worn parts can increase power loss.