Harley-Davidson Fat Boy vs Harley-Davidson Nightster Special

The Harley-Davidson Fat Boy (2025) and the Harley-Davidson Nightster Special (2025) 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 Harley-Davidson Nightster Special is a cruiser with 975 cc, 88.5 hp and 225 kg. Power-to-weight with the rider: 264.8 hp/ton versus 295.0 hp/ton. On this measure the Harley-Davidson Nightster Special is 11% ahead.

In the simulation the Harley-Davidson Fat Boy covers 0-100 km/h (speedometer) in 3.54 s and the Harley-Davidson Nightster Special in 3.17 s; the Harley-Davidson Nightster Special is quicker by 0.38 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 49.1 m for the Harley-Davidson Nightster Special (ABS unknown, class assumption: no ABS). Calculated top speed: 201 km/h (estimated from power and drag) versus 180 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 Harley-Davidson Nightster Special. Open the interactive app (currently in Turkish) to watch the run side by side and change the load.