Kawasaki Vulcan S vs RKS RZ125

The Kawasaki Vulcan S (2026) and the RKS RZ125 (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 Kawasaki Vulcan S is a cruiser with 649 cc, 59.9 hp and unlisted weight; the RKS RZ125 is a sport bike with 125 cc, 14.5 hp and unlisted weight. Power-to-weight with the rider: 226.5 hp/ton versus 63.8 hp/ton. On this measure the Kawasaki Vulcan S is 255% ahead.

In the simulation the Kawasaki Vulcan S covers 0-100 km/h (speedometer) in 4.49 s and the RKS RZ125 in 13.42 s; the Kawasaki Vulcan S is quicker by 8.93 s. In the 100-0 km/h brake test, braking distance without the 0.3 s reaction time is 44.7 m for the Kawasaki Vulcan S (with ABS) and 36.4 m for the RKS RZ125 (with ABS). The RKS RZ125 stops 8.3 m shorter. Calculated top speed: 173 km/h (estimated from power and drag) versus 125 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 model-specific parameters calibrated against published road tests for the Kawasaki Vulcan S and class-average calibration (no accepted model-specific road test) for the RKS RZ125. 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.