Occasionally, you come across a new bike that just feels right. Within a few laps, you feel like you’ve been riding it for years; you know exactly how it handles and responds.

The KTM 300SX is not one of those bikes. This bike shook things up when it was introduced last year. It was a completely new model, a whole new concept, and a different take on two-stroke motocross bikes. Only now, with the release of the 2024 model, are we starting to grasp what this bike means for motocross.

STARTING OVER

Prior to last year, KTM had never offered a 300SX for the U.S. market; buyers would have to build one from a kit or start with a modified off-road bike. Some riders attempted to race the 300XC in motocross, but it wasn’t quite the right fit, especially with the transfer port fuel injection (TPI) introduced in 2018.

The brand-new two-stroke engine platform that KTM introduced with the 2023 300SX had electric start, an electronic power valve, and throttlebody fuel injection. While each of these features had been seen before individually, the way KTM integrated them in the 300SX was entirely new. The bike’s CPU controlled everything, including the power valve’s opening distance and timing, a first for a production bike. The chassis was given the same general specs as the four-strokes, making it more rigid with more anti-squat tendencies than the older frames. The suspension still featured a WP Xact air fork in front and an Xact shock in the rear. The brakes and hydraulics were still Brembo, and premix was done manually by mixing oil and gas together.

This bike appeared and left us amazed. It was fast, aggressive, and demanded a change in how we approached motocross. We spent a year trying to adapt. Now, with the 2024 model unchanged, it gets a second chance to make a first impression. This time we’re ready for it. We know that the 300SX is something entirely different, and we’ve been honing our two-stroke skills.

PRESS THE GREEN BUTTON AND HOLD ON

The first thing to note about this bike is that it has two maps available on the handlebar switch, each with very different characteristics. The green map at the bottom provides an exhilarating and incredibly fast ride. While modern 450 four-strokes might technically produce more peak power on a dyno, the 300SX feels more potent on the track due to the way the power is delivered. It starts off smooth down low and runs extremely clean. With good throttle control, it can be ridden in the lower range where it still delivers respectable lap times. However, the power kicks in with a steep, rapid surge. This kind of power delivery might catch modern four-stroke riders off guard. While the 300SX is more manageable than a traditional 250 two-stroke, it’s still more challenging to control than a 450. On the flip side, it opens up opportunities for different riding techniques. Most 450 riders have learned to use the clutch to manage hard braking; with the 300SX, you can brake without touching the clutch and then apply throttle old-school style. This bike teaches real technique, making you a better and more precise rider.

Most riders opt for the green map because it’s exciting. For professionals, this is perfectly fine. However, for most others, the gray map is a better choice. It doesn’t deliver the intense hit and isn’t as thrilling, but it’s less tiring and offers improved overall performance. It can be hard to accept this trade-off. During a race, riders often switch back and forth between maps, and it’s easy to do on the fly. They usually start with full power and then switch to the mild map when they start feeling tired, although they often feel like they are leaving something on the table. KTM could benefit from offering more than just two maps, perhaps around five, to cater to a wider range of preferences. JD Jetting already has a piggyback fuel controller that allows some mapping adjustments, providing more adjustability, although not on the fly.

Despite KTM’s claim that there are no changes to the 2024 bike, it wouldn’t be surprising if mapping updates are offered by dealers throughout the year. Reports have indicated occasional glitches, similar to what happened with the transfer port injection two-strokes, which took over a year to resolve. In this case, the 300SX may occasionally bog down when the throttle is closed and reopened at high rpm, typically on fast downhills like the one at Glen Helen, albeit not every time. While it might not be a significant issue, it’s hard to imagine a scenario where the hesitation, more of a hiccup, would pose a risk during a fast downhill.

THE KTM FEEL

In terms of handling, much has already been said about the new frame on KTM’s four-strokes. The 300SX isn’t too dissimilar. Overall, KTMs consistently deliver excellent performance in turns. They are easy to steer without being overly busy. Weighing 223 pounds without gas, the 300SX is very lightweight, 6 pounds lighter than the 450SX. It’s effortless to initiate a turn and maintains a stable platform throughout. However, the power delivery of a two-stroke significantly differs from a four-stroke as you accelerate out of the turn, resulting in a more aggressive behavior. The shock is superb, but the 300SX lacks the rotating mass of a four-stroke, making it more susceptible to being thrown off course by square edges and off-center impacts.

The same applies to the fork. The WP air fork is highly regarded and provides a light, plush, and highly adjustable ride. Irrespective of adjustments, a 300 two-stroke tends to feel the impact of bumps more significantly than a 450 four-stroke, an advantage that the latter is hard to match even with suspension tuning alone.

THE NEXT LEVEL

If it seems like we’re criticizing the revered tradition of two-stroke motocross, that’s not the intent. Few people love two-strokes more than us. The fact that the 300SX isn’t as stable as a KTM 450SX-F won’t surprise anyone who has ridden both, and it’s not unique to the 300SX. Despite the challenges, riding the KTM 300SX inevitably reignites the excitement for two-stroke MX. It’s exhilarating to ride and rewarding to race. Moreover, nothing else on the track sounds as impressive.