Harley-Davidson Fat Boy vs Kawasaki Vulcan S

The Harley-Davidson Fat Boy (2025) and the Kawasaki Vulcan S (2026) are compared with the same Moto Kıyas physics model under identical conditions: flat dry asphalt, no wind, a 75 kg rider and no passenger. The Harley-Davidson Fat Boy is a cruiser with 1,923 cc, 103.3 hp and 315 kg; the Kawasaki Vulcan S is a cruiser with 649 cc, 59.9 hp and unlisted weight. Power-to-weight with the rider: 264.8 hp/ton versus 226.5 hp/ton. On this measure the Harley-Davidson Fat Boy is 17% ahead.

In the simulation the Harley-Davidson Fat Boy covers 0-100 km/h (speedometer) in 3.54 s and the Kawasaki Vulcan S in 4.49 s; the Harley-Davidson Fat Boy is quicker by 0.94 s. In the 100-0 km/h brake test, braking distance without the 0.3 s reaction time is 49.1 m for the Harley-Davidson Fat Boy (ABS unknown, class assumption: no ABS) and 44.7 m for the Kawasaki Vulcan S (with ABS). The Kawasaki Vulcan S stops 4.4 m shorter. Calculated top speed: 201 km/h (estimated from power and drag) versus 173 km/h (estimated from power and drag).

All values are an estimated simulation, not road-test measurements. Technical data comes from the sources listed below; the model uses class-average calibration (no accepted model-specific road test) for the Harley-Davidson Fat Boy and model-specific parameters calibrated against published road tests for the Kawasaki Vulcan S. Missing manufacturer data (weight) is estimated by class regression, not measured. Open the interactive app (currently in Turkish) to watch the run side by side and change the load.