The Ultimate Motocross Bike

250 Two-Stroke
There's no question that a 250cc two-stroke has a lot to offer. In addition to lightness and maneuverability rivaling or even surpassing 250Fs, there's the power. A strong-running stock 250 makes peak power in the ballpark of a stock 450. This is when even good riders can't effectively use all of a 450's power. This ballpark is a happy place to be.

Consider the parts of motocross one at a time. First, there's the start. A two-stroke can get a start close to or beside 450s, and you may even beat them. This is more likely on short starts than long, high-speed or uphill pulls. Once on the track, a 250 allows great corner speed and control in ruts. In rapid direction changes, a 250 flicks side to side with equal or less effort than a 250F and much easier than a 450. Then there are the jumps. You think there's a reason that nearly every freestyle jumper on the planet rides a two-stroke? Typically they offer great control in the air thanks to light weight and a smaller gyro effect from the engine. And they start easily without much thought. As far as lap times go, a variety of riders-in terms of skill and age-were able to lay down hot laps even on the KTM, a bike that still suffers from some of that "it's just different" syndrome. We have a killer suspension setup on our bike and switched between stock and FMF exhaust during our testing.

Still, a lot of these lap times are undoubtedly slower than they could be as riders struggled to get used to the different two-stroke feel. As good as a modern 250 is, it's quite different from a four-stroke. The power comes on more suddenly with more hit, and below that hit the roll-on is less effective than even a small-bore four-stroke. A thumper lets you get a bit lazy, a little sloppy and it covers up for you. A two-stroke demands the correct gear for the situation, whereas a four-stroke has nearly twice the length of usable power in every gear. And don't forget the lack of compression braking; you'll need to remember how to carefully use that rear brake again. Jesse clearly pointed this out: "I couldn't get comfortable on the two-stroke immediately. It lights up like a firecracker, and the bike is so light that I find myself catching up to it worse than when on most 450s. If it was my only bike, I'd adjust and start to enjoy it to a level, but in a straight-up comparison it doesn't come close to the easy power and handling of a four-stroke."

But most of us used to ride two-strokes, and if you ride one exclusively, you'll automatically use its strengths to advantage. But in a comparison like this, where riders had to jump from four-strokes to the two-stroke, the differences are highlighted.

You cannot be lazy. You not only need to be in the proper gear for a turn, you'll need to grab a shift immediately after exiting the corner as well. The same is true on jumps, especially to get the snap you want on a steep jump face. A two-stroke makes a lot of power, but it produces boost over a shorter rpm range than a four-stroke-even a 250F. If you look at the radar runs, wherever the line goes up steeply the bike is pulling hard. You'll see that there are places the 250 is accelerating more violently than the 450. For some riders that isn't an issue, but for others it tires them out and causes early arm-pump.

But for a low-maintenance, high-fun race or moto-playbike, a two-stroke is still a winner and perhaps has the highest smile-per-dollar ratio. A perfect example is Jimmy Lewis. This KTM 250 SX is his moto bike for the year, and it's set up for him and his riding style. "This bike is completely competitive in the longer motos that Vet pros run," he said. "I can ride it hard and stay aggressive, but I don't get whipped like I do on 450s. Most of the time I can get a good start against big bikes, too. For sure a two-stroke is the most cost-effective to own of the bikes in this group. As good as they are stock, there are decent ways to make the bike better with cash. I have to pay more attention in the first few laps on a 250 two-stroke, but later in the moto it's easier for me to keep on my pace."