KTM's XC-W models are the trailbikes in the KTM lineup. But that has to be clarified a little, as these machines are trail race bikes, meaning built with an eye for off-road racing on single-track trails. Hence, KTM invited Cycle World to the Rattlesnake National Enduro in Cross Creek, Pennsylvania, to test most of the range. Let's start with this report on the KTM 250 XCF-W ($8599) and 350 XCF-W ($9499).
The biggest change to the 2014 KTM lineup involves the 250cc four-stroke, which got an all-new engine, plucked right out of the company’s 250 SX-F motocrosser but tuned for more torque. This motor borrows some key features from the 350 engine family in the transmission and clutch. Hydraulically activated, as in all KTMs, the clutch also uses the diaphragm spring and internal damping shared with most of the models now. KTM says the 250’s head flows 10 percent better than before, and although unique cams and a specifically tuned ECU optimize torque and traction over outright horsepower, that’s been bumped as well. A 42mm Keihin throttle body feeds both bikes, and a new larger, 196-watt AC alternator powers the system. As on the 350, the starter motor has grown and a larger 4Ah battery helps crank it harder (cold-starting was an issue on previous bikes).
The frame of the XCF has changed, mostly for weight savings but also to accommodate the 250 engine’s new mounting. Lighter lower frame rails and a more solid headstay provide better handling. The swingarm on all XC-Ws has been lightened a bit, while chain guide mounts have been strengthened. All this leads to a slightly lighter four-stroke for 2014. To round out the package, the suspension valving has been altered to match the chassis changes, with the 250 and 350 sharing the same settings and spring rates.
It’s difficult to tell the differences in the smaller four-strokes by sight, but you can tell when riding them. As you’d suspect, the 250 feels a lot less grunty on the bottom, but it also feels a lot lighter all the time; compared to the previous 250, the new engine gives the bike the power feel of a 280cc machine, while keeping the free-revving and playful feel of a 250 four-stroke. The old KTM 250 motor was reluctant to pick up rpm without a little help from the clutch; the new one rolls on so much better. On top of that, the FI lets the bike chug down so much lower than I remember previous bikes being willing to do without wanting to stall.
The clutch is used for skidding time, not to boost or get a jump in power. Now you just use the throttle for that. The 250 shines with an overall power pull that is long and linear while grabbing traction all the time. The rear tire doesn’t spin that much, even when conditions are excessively slippery. The 250 isn’t fast compared to bigger bikes, especially if the rider isn’t twisting the throttle and making noise. But this bike has way more torque and drivability; riders who want the lightest weight and nimble handling can have that sensation, with enough power to make performance modifications to engine unnecessary.
The 350 XCF-W has come a long way since its introduction as well. Torque was increased without losing power anywhere else in the rpm range via a heavier crankshaft and shorter duration cam timing, which also helps decrease the compression-braking feeling. The motor is still a revver compared to bigger four-strokes, but the 350 has a much lighter feel when riding, and enough torque for heavier riders to appreciate. And it’s not slow. It can and will break loose if you are heavy on the throttle, and its roll-on pick-up is nothing to be ashamed of: The 350 sings up to a 12,000-rpm ceiling, and boasts a claimed 45 horsepower. It basically feels like a 450 of just a few years ago. It likes to rev to go fast, but can chug if that is your style—all while feeling 20 pounds lighter than any 450, especially off-road specific ones.
The 250 and 350 share identical suspension; the handling of both KTM four-strokes is should be considered the standard or baseline for a single-track machine. Although it’s on the softer side of a racing set-up for a faster rider, it is exceptional for a stock machine. Keeping the simplicity of the PDS linkage-less rear suspension (an XC-W trademark) and utilizing the 48mm open-cartridge WP fork, the bike is neither too stiff for trail riding nor too soft for racing. If anything, the fork was noticeably softer than that of the two-strokes I rode, and some of that may be attributed to compression- braking putting more weight on the front wheel some of the time.
KTM sought better traction with the new 2014 bikes, especially on the four-strokes. The company clearly succeeded, as these bikes are very planted feeling for acting so light. Suspension action on small bumps, roots and rocks has the wheel tracking without having a loose feel, thanks to good rebound control. It’s easy to move all over the bike, and high-quality controls, all very adjustable, make personalization easy. The suspension adjustments, especially the high-speed compression on the shock, help tune the attitude of the bike. I ran a sag setting of between 105-110mm on the shock, which was close to the 30mm of bike-only sag, confirming that the spring rate was working for my 185-lb. weight.
Now, the big question: Two-stroke or four-stroke? There is no blanket answer. It comes down to what you intend to do with the bike and what riding requirements you have. If you are looking for really long power spreads that have a very wide power difference between top-end pull and low-end lug, without having to shift much, the four-stroke definitely shines. Additionally, the four-strokes feel more connected to the ground or planted. You also don’t have to fuss with mixing the gas and oil, and durability is so good that working on the motor should never be a concern well into the hundreds of hours, just like the two-strokes. In California, the four-strokes are also green-sticker legal.
Next question: 250 or 350? The heavier you are, the more the added power of the 350 becomes a benefit. How much do you plan on wringing the bike out, throttle to the stop? That’s where you’ll really need to ride to expose the true power differences between these bikes. At a casual pace, they both have plenty of torque; the 350 just requires you to be a little more attentive with the throttle when traction is low. The lighter feel of the 250 is noticeable and comes into play the harder you ride the bike and the more technical the trail.
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