Harley-Davidson Street Bob vs Kawasaki Z900

The Harley-Davidson Street Bob (2025) and the Kawasaki Z900 (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 Street Bob is a cruiser with 1,923 cc, 91.2 hp and 293 kg; the Kawasaki Z900 is a naked bike with 948 cc, 122.0 hp and 213 kg. Power-to-weight with the rider: 247.8 hp/ton versus 423.7 hp/ton. On this measure the Kawasaki Z900 is 71% ahead.

In the simulation the Harley-Davidson Street Bob covers 0-100 km/h (speedometer) in 3.49 s and the Kawasaki Z900 in 3.13 s; the Kawasaki Z900 is quicker by 0.36 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 Street Bob (ABS unknown, class assumption: no ABS) and 43.7 m for the Kawasaki Z900 (with ABS). The Kawasaki Z900 stops 5.4 m shorter. Calculated top speed: 194 km/h (estimated from power and drag) versus 234 km/h (manufacturer claim).

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 Street Bob and model-specific parameters calibrated against published road tests for the Kawasaki Z900. Open the interactive app (currently in Turkish) to watch the run side by side and change the load.