Harley-Davidson Sportster S vs Yamaha Sirius FI

The Harley-Davidson Sportster S (2025) and the Yamaha Sirius FI (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 Sportster S is a cruiser with 1,252 cc, 120.7 hp and 228 kg; the Yamaha Sirius FI is a cub / underbone with 114 cc, 8.6 hp and 98 kg. Power-to-weight with the rider: 398.3 hp/ton versus 49.6 hp/ton. On this measure the Harley-Davidson Sportster S is 703% ahead.

0-100 km/h (speedometer): Harley-Davidson Sportster S 2.97 s, Yamaha Sirius FI not reached (top simulated speed 89 km/h). In the 60-0 km/h brake test, braking distance without the 0.3 s reaction time is 16.1 m for the Harley-Davidson Sportster S (with ABS) and 18.5 m for the Yamaha Sirius FI (ABS unknown, class assumption: no ABS). The Harley-Davidson Sportster S stops 2.4 m shorter. The standard 60-0 test is used because one calculated top speed is below 110 km/h. Calculated top speed: 194 km/h (manufacturer claim) versus 88 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 Harley-Davidson Sportster S and class-average calibration (no accepted model-specific road test) for the Yamaha Sirius FI. Open the interactive app (currently in Turkish) to watch the run side by side and change the load.