09 Ktm 300 Xc W
The future of two-stroke dirt bikes has been in flux for years. While there is a modern resurgence in their popularity, both in motocross and off-road riding, in the motorized recreation arena in general, engines that burn both gas and oil have been slowly fading away. Yet KTM, especially with the 2020 launch of five TPI two-strokes, has bucked that trend and is standing firmly in the corner of all two-stroke fanatics by continuing to develop, improve, and expand their two-stroke offerings.
The bikes in question are three XC-W models (150, 250, and 300) and two XC models (250 and 300). The simplest way to think about the difference between KTM's XC and XC-W models is that the W stands for wide ratio transmission, and they come with lights and softer WP XPLOR suspension (including the PDS shock). The W models are aimed at more technical terrain and trail riding. The XC models are closer to the SX bikes, have WP XACT suspension (including AER fork and linkage), semi-close ratio transmission, and no lights. They are more race-focused machines meant to be used in racing like GNCCs, WORCS, and Grand Prix style events.
There are a lot more changes to the XC-W line than the XC line, since KTM's production plan is typically to make major changes to the SX/SX-F which may or may not also coincide with changes to XC/XC-F models, then those changes trickle down to the XC-W/XCF-W/EXC-F models. In 2019, the SX and XC models received a new, stiffer frame and new bodywork that have shown up on the XC-W 150, 250, and 300 for 2020. But, since we could only race one model, here we are going to focus on the 2020 300 XC TPI.
On The Track: 300 XC TPI
Rather than have us just ride the new bikes, KTM added a pretty rad twist to this 2020 bike intro. They decided to have the launch at the 7th round of WORCS Racing at the Grays Harbor ORV in McCleary, Washington. This was a perfect place to showcase the new bikes, but unfortunately, because of the nature of racing, we could only ride one model. I opted for the 300 XC TPI because it is closer to the SX models, and since I hadn't raced a WORCS race before, I figured more displacement couldn't hurt.
The Washington round was way more tight and technical than most modern WORCS courses featuring a moderate motocross track and an off-road loop of nearly every kind of off-road terrain. There was true, one-lined single track through dense forest, connected by embedded-rock two-track, loose-rock gardens, trails with all sizes of roots and stumps, open fields, and one giant pile of mulch about a football field long. Some of it was dry and dusty and other sections were goopy and slick. It was a great mix of riding conditions that highlighted what any off-road bike would likely encounter.
Now on to the bike. Since we've already ridden a 2019 KTM 300 XC-W TPI last year, you can check out that test for a full break down of the TPI (Transfer Port Injection) technology. The Cliff Notes version is that there are two fuel injectors that spray gas only into the transfer ports on both sides of the cylinder. Oil is added automatically to the bottom of the engine and the throttle body only controls how much air is going into the motor.
Stabbing the magic button, the 300 come to life instantly but still takes some time to warm up properly. Once the motor is to temp, my first ride on the 300 XC TPI was the morning practice of the race. The first lap I was mostly focused on learning the coarse but after that I started to pay more attention to what the bike was doing. At first I was shifting way too much, treating the 300 like a smaller two-stroke. Since I didn't know how tight the turns where going to be or how steep the down-hills were, I kept dropping into first which was unnecessary. In first, the bike would nearly loop out coming out of the corners aggressively since there is so much torque for a two-stroke. Once I got into the grove and rode the bike in second and third, I was much faster and smoother.
The bike has so much torque that I could really let it drop down low in the rpm and it still wouldn't fall on its face when I blipped the throttle. This is also the magic of the TPI. With the computer monitoring rpm, throttle opening, ambient air pressure, and other technical things, it feeds the 300 with just the right amount of oil and gas to match the throttle's amount of air and makes for a crisp, snappy throttle response every time. This was one of my favorite parts of the bike and I barely had to touch the clutch.
That being said, the TPI bike has a more linear power delivery than the carbureted 300s I've ridden in the past. This gives the XC a more four-stroke like power than a tradition two-stroke power band with a surge of power in the middle, and less on bottom and top. In the race, what this translated to was incredible traction. With two-strokes, typically I notice less of a connection with the ground, just based on the way they make power and overall feel. But with the 300 XC TPI, I felt like every twist of the throttle, no matter how small or big, or slow or fast, translated into forward movement, rather than wheel-spin or sliding-out. It really gave the bike a modern FI feel like we've had with fuel-injected four-strokes for a while now.
I hesitate to call it a downside, but some riders might feel like this linear power delivery has less overall excitement than a carbureted bike. I tend to disagree that the power is less, it is just metered out in a more controlled way. If you want power, just twist the throttle. At no point during the race was I thinking, "I could use more power." If anything, I was starting to get jealous of the riders on the 150 XC-W, since the course was so tight. The 300 XC definitely reminded me of a 450 in the way that you are sort of along for the ride, rather than the other way around.
As far as the handling goes, the 300 XC TPI is noticeably softer than the SX models at also use the XACT fork and shock. If we were racing a faster WORCS round or just the motocross track, I'd want to stiffen up both ends of the bike. If I didn't grease the landing of a jump or treat the doubles as two singles, I'd use most of the suspension travel pretty easily. But, other than just adding a little more preload to the shock to get the bike more balanced, I left the stock, plush set-up for the off-road section of the race, which was about 90 percent of the course.
One thing that the XPLOR fork (on the W models) has over the XACT fork when riding off-road is initial comfort. While the air spring WP fork on the XC has a plush overall action and pretty solid bottoming resistance on the trail, the very beginning of the stroke has a tiny bit of reluctance to start to move. This is noticed when the fork is light (under acceleration, for example) and you hit a square edge or root - you get a little more of a pop and transfer of energy rather than the fork just soaking it up.
On the moto track, I'm not the biggest proponent of the way KTMs handle with this latest generation frame, but I do like the way they handle off-road. Since there aren't as many tight, 180-degree turns on trails (typically) and off-road riding is more about stability and agility, I think the 2020 300 XC really shines in the handling department when riding single track and more open trails alike. It feels lighter than a 300 should and I was able to get the bike to go where ever I wanted it too - there were a ton of rocks, roots, branches to avoid and I could snap the bike around them very easily. The softer suspension settings of the XC work in congress with the stiffer frame to offer precision and comfort on the trails, over rocks and roots and through the trees. The only time that I had an issue was on the moto track with the inside ruts. I feel like the bike is somewhat reluctant to start the turn and commit to the rut.
Overall
While this is a test of the 2020 KTM 300 XC TPI bike, in the back of my mind the whole time I was riding this bike I was thinking about if the technology on these TPI machines would be good or bad for two-stroke motocross models. And, at the end of the day, I think that for the average motocross rider, and racer, TPI would not put a moto two-stroke at a disadvantage. For the top-level racer, they might want that punchier hit of the carbureted bike, but I don't know who is racing at a high level on a two-stroke (other than amateurs on 125s). For off-road racing, the way the bike makes traction and the crisp response of the motor is near perfect. Plus, the other benefits of fuel injection (no mixing gas, using a ton less oil, not having to jet for altitude or weather, instant throttle response) really make this 300 XC TPI bike a more convenient bike to own and ride.
Now, I've always been more of a four-stroke fan, and that could definitely bias my opinion to liking a bike with less of a pipy hit and that I can just put straight gas in it. But, I guess I've just drunk the Coolaid and there's no going back for me. Oh, and I got second in my class so there's an extra plus as well!
Source: https://www.vitalmx.com/product/guide/Bikes,6/KTM/300-XC-TPI,16706
0 Komentar