2021 KTM 450 SX-F Dyno Test

How much power does KTM’s flagship motocross bike make in 2021?

In a segment as competitive as the 450cc motocross bike category, the KTM 450 SX-F has a lot going for it. The Austrian machine is the lightest in the class, features the strongest brakes, an excellent Brembo hydraulic clutch, a neutral-handling chassis, and suspension that offers more comfort than any of KTM’s prior flagship motocross models. Another standout feature of the 450 SX-F is its engine. It blends a phenomenal balance of rideability with its linear power delivery while also delivering competitive figures on the dyno throughout the rpm range—namely from 7,000 rpm on up. At peak, the 450 SX-F emits 54.8 hp at 9,500 rpm and 34.6 pound-feet of torque at 7,400 rpm.

2021 KTM 450 SX-F Dyno ChartRobert Martin

“The 2021 KTM 450 SX-F’s engine character is very vet-friendly, but surprisingly torquey and strong yet also easy to ride. It has a very controllable bottom-end with a strong midrange transition, and can either be short-shifted and lugged or revved with good results.” —Casey Casper

2021 KTM 450 SX-F Engine Specifications

Engine Type: Liquid-cooled, SOHC, four-stroke single-cylinder; 4 valves/cyl.
Bore x Stroke: 95.0 x 63.4mm
Displacement: 450cc
Compression Ratio: 12.75:1
Fuel Delivery: Electronic fuel injection