Words: Caleb Tennant

Featuring revolutionary two-stroke technology to provide enhanced power and added simplicity, the 2023 KTM SX range takes performance up a gear as we experience the 300 SX, 250 SX and 125 SX for this Tested review.

Among a list of updates for this new generation, the KTM two-stroke motocross bikes boast new electronic fuel injection, electric start and selectable mapping options to extract the most from each model. Detailed has a more extensive technical rundown.

Being one of the first people to test the new 2023 two-stroke models was extremely exciting and every bit worth the wait. I was able to get five laps on each bike at the iconic RedBud motocross track, being the limited amount of bikes available at this point, but it was a great opportunity to get a feel for each.

KTM has been working hard to keep up to date with the development of two-strokes and has really picked up the game for the 2023 models. The main difference I could feel with these new bikes is how clean the power delivery and the throttle response are thanks to the fuel injection – the bikes have no dead spots and it’s really easy to find that sweet band with smooth and predictable power.

The 125 SX has its own frame, but the 250 SX and 300 SX models both fit into the same frame, which enabled a swift transition when jumping between them as they all feel very similar in the chassis, balance and stability. I was able to ride each different bike and feel comfortable within a couple of laps, I just had to adapt to the different gearing ratio and the power delivery of each model.

Image: Supplied.

Similar to the 2023 SX-F four-strokes, I’m a big fan of the new seat and ergonomic position on the SX range, which really lets you maintain comfort without sliding around or struggling to get into a good riding position. It’s a step forward and incredibly modern.

Another thing that impressed across the 2023 SX range is the different mapping options that can be switched easily with a touch of the button on the handlebar. The difference between the two maps on each bike is prominent, as in the first map the bike is leaner, which makes it a lot smoother, not as hard-hitting. When using the aggressive option, there is a noticeable increase from the bottom-end to mid-range power.

The first bike that I rode during the test was the 250 SX and it was evident right away that you didn’t have to be particular with gear selection –  the bike pulls really strongly and feels a lot crisper than previous models did before. It was noticeably light in terms of the feel and easy to put where I wanted during corner entry and exit.

After the 250, I hopped on the exciting new 2023 KTM 300 SX, which felt very similar except for that extra kick of power. It almost feels like you are riding a 450 in certain ways with a bunch of two-stroke torque and it was super-lenient when riding in taller gears. There were some corners I did in fourth gear and it still pulled out well, which signifies the power on hand.

In the beginning, it was hard keeping the front wheel down coming out the corners, but once I was comfortable with 300 SX I could ride in the more aggressive mapping and feel good without the power being overbearing. Like with the 250, the power is very crisp and the chassis handles very well, so I think this big bore model is going to be extremely popular upon release.

Image: Supplied.

Jumping on the 125 SX to conclude the test, it was underwhelming at first after hoping off the 300 with so much manageable power. During the first couple of laps,  I struggled to find that perfect gear where the bike worked best, but once I started figuring it out it was a lot of fun to ride, as you’d suspect.

Compared to the previous 125s I have ridden, this bike definitely has more bottom to mid-range power and pulls out of the turns harder. I definitely like the more aggressive mapping with this bike, giving it the much needed extra hit after hoping off the bigger capacity machines. It’s the type of bike that rewards riding hard and the chassis will work with you every step along the way in doing so.

On the 125 SX chassis, combined with the WP Suspension, it let me do pretty much whatever I wanted with the bike. It has a great balance and I felt like I could come into the turns, barely touch the Brembo brakes and the bike would still pitch how I needed and rail through the corners.

It is neat to see KTM extending the future of two-strokes with the introduction of this latest technology, which is sure to raise the bar. The ease of having the electric start and fuel injection means less hassle and more time to enjoy the light and playful nature of the SX range. That’s what it’s all about!

Specifications

300 SX
Engine type: 293.2cc, liquid-cooled, single-cylinder, two-stroke
Bore/stroke: 72×72mm
Transmission: Five-speed
Starter: Electric
Clutch: Brembo hydraulic
Traction control: No
Launch control: No
Front suspension: WP Xact 48mm
Rear suspension: WP Xact shock
Front brake: Brembo 260mm disc
Rear brake: Brembo 220mm disc
Tires: Dunlop Geomax MX33
Weight: 219.13 lbs (without fuel)
Price: $9199 MSRP plus $485 freight
Availability: Starting from September 2022
Further information: www.ktm.com

250 SX
Engine type: 249cc, liquid-cooled, single-cylinder, two-stroke
Bore/stroke: 66.4×72mm
Transmission: Five-speed
Starter: Electric
Clutch: Brembo hydraulic
Traction control: No
Launch control: No
Front suspension: WP Xact 48mm
Rear suspension: WP Xact shock
Front brake: Brembo 260mm disc
Rear brake: Brembo 220mm disc
Tires: Dunlop Geomax MX33
Weight: 219.13 lbs (without fuel)
Price: $8949 MSRP plus $485 freight
Availability: Starting from September 2022
Further information: www.ktm.com

125 SX
Engine type: 124.8cc, liquid-cooled, single-cylinder, two-stroke
Bore/stroke: 54×54.5mm
Transmission: Six-speed
Starter: Electric
Clutch: Brembo hydraulic
Traction control: No
Launch control: No
Front suspension: WP Xact 48mm
Rear suspension: WP Xact shock
Front brake: Brembo 260mm disc
Rear brake: Brembo 220mm disc
Tires: Dunlop Geomax MX33
Weight: 203.7 lbs (without fuel)
Price: $7949 MSRP plus $485 freight
Availability: Starting from September 2022
Further information: www.ktm.com