RKS RZ125 vs Yamaha R25

The RKS RZ125 (2026) and the Yamaha R25 (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 RKS RZ125 is a sport bike with 125 cc, 14.5 hp and unlisted weight; the Yamaha R25 is a sport bike with 250 cc, 35.4 hp and 169 kg. Power-to-weight with the rider: 63.8 hp/ton versus 145.1 hp/ton. On this measure the Yamaha R25 is 127% ahead.

In the simulation the RKS RZ125 covers 0-100 km/h (speedometer) in 13.42 s and the Yamaha R25 in 6.40 s; the Yamaha R25 is quicker by 7.01 s. In the 100-0 km/h brake test, braking distance without the 0.3 s reaction time is 36.4 m for the RKS RZ125 (with ABS) and 40.0 m for the Yamaha R25 (ABS unknown, class assumption: no ABS). The RKS RZ125 stops 3.6 m shorter. Calculated top speed: 125 km/h (estimated from power and drag) versus 158 km/h (GPS measurement).

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 RKS RZ125 and model-specific parameters calibrated against published road tests for the Yamaha R25. Open the interactive app (currently in Turkish) to watch the run side by side and change the load.