Jesse Ziegler | July 12, 2018
Big Changes = Big Results?
We get our first taste of the all-new 2019 KTM 250 SX-F.
The KTM 250 SX-F is a light and nimble small-bore MX ripper. We’ve loved them here around the Cycle News office in the past because they give you the fun feel of a small bike with big top-end power wrapped in a package of high-end componentry. They require a throttle-cable-stretching ride style to really sing, and that’s okay with us. Telling our friends the bike we’re riding has a 14,000-rpm limit is pretty cool, too.
Also, they don’t let us get lazy out there. You have to really ride a KTM 250 SX-F to get around a track efficiently and fast, and that engagement is intoxicating.
Our 2019 KTM 250 SX-F first test showed us that KTM is sticking to their high-rpm power play in the 250 class and they simply won’t stop tweaking on a proven, widely admired MX platform. The new 250 SX-F is improved in all areas of performance as far as we can tell after a few days of ripping around.
Updates to the 2019 KTM 250 SX-F include the changes we first saw on the 2018 KTM 450 SX-F Factory Edition. And the entire KTM motocross lineup is sharing in the bulk of these upgrades. Dig into details with our 2019 KTM Motocross Lineup First Look by clicking HERE.
PHOTOGRAPHY BY RON LAWSON
On-Track Highlights
Right away, the 2019 KTM 250 SX-F feels familiar. The excellent Brembo clutch feel and comfortable chassis dimensions are ready to interact with the rider. The e-start (powered by a punchier battery) fires up cleanly and the tune belting out of a redesigned exhaust system sounds gritty but substantial and efficient. Knocking it into gear, via the new Pankl transmission, is clean and the new diaphragm spring (DS) clutch system releases power in a nice, controlled way. Basically, this bike falls directly in line with KTM’s tradition of high-end, well-built and nicely finished motocross machines.
And the resulting ride experience follows suit. The engine updates (optimized mapping of the ECU, the new exhaust cam profile, airbox update, velocity stack change, etc.) don’t drastically shift the power delivery away from last year’s bike. Or the year before, for that matter. But it sure does feel good.
The 2019 KTM 250 SX-F gets many of the same updates as the 2018 450 SX-F Factory Edition. In other words, it is significantly updated.
KTM keeps creeping toward more bottom-end power with these incremental changes to the proven power plant, but they’re not making a drastic shift in engine character here. Many 250F races are won at the end of the start straight and by young guns leaving the throttle wide-freaking-open. And this bike is engineered to do just that anywhere from your local track to Loretta’s to the World MXGP series. It’s a screamer. It wants to turn the crank as fast as possible.
The KTM’s power delivery makes it really fun to ride. It rarely gets away from you or intimidates you. Thanks to its linear progression, you can essentially bury the throttle to the stop and enjoy the ride. It doesn’t surge or snap in the midrange and the top-end pull is never ending. It’s not a torque monster but shifting into the right gear makes it extremely efficient at powering through corners.
In its class, nothing feels lighter than the KTM 250 SX-F.
There are faster bikes in the 250F class from 1000-5000 rpm, for sure. But they require an upshift much sooner than this KTM. So, work on your corner speed and enjoy those gears a little longer with a KTM. Yes, we’d like to have massive torque and pull out of the bottom to go along with this impressive top end—but we could get a 350 for that. Or, we may even want to shift the whole power allotment down toward the lower rpm range a bit more. Aftermarket exhaust systems, including the KTM PowerParts FMF slip-on units, will do this exact thing. Just remember, you’ll likely have to shift more down the straights.
The stock exhaust system deserves some comment here. It’s new—redesigned to provide better power and sleeker implementation into the bike. Also, you don’t have to remove it to get the shock out anymore. That’s convenient.
How about the maps? Well, they are controlled by the same map switch system as before, and honestly, we simply leave the 250 in number “2” all the time. Launch control for starts is great and the traction control, while not used as often on this smaller-displacement model, still makes a big difference when the tracks get dry and hard. This system was years ahead of KTM’s competitors when it came standard on KTM’s SX-F lineup in 2017. Now, other manufacturers are getting closer, but none have integrated dual map switching, traction control and launch control all rolled up into one switch. It’s clear, intuitive and just another example of high-quality KTM componentry.
The rider controls the KTM, not the other way around.
Getting A Handle On Handling
I’m at the point in my life where I’m very much out of the stock shock spring range on most 250Fs. I’m not on a diet or training for anything, to put it bluntly. I’ve ridden this bike with the stock spring and a stiffer spring. And let me tell you, that modification is definitely worth it, at least for my 180 pounds. The stock spring is just eating all of its free sag up when I pre-load the crap out of it to get the right race sag setting. At that point, it affects the bike’s ability to settle in corners and that’s where I really need a bike to handle best. So slapping in a beefier shock spring made a huge difference. The bike settled better when riding at the proper free sag settings and I could focus on the rest of the setup instead of wondering why the chassis wasn’t balanced. Get the right spring if you’re over 170 pounds.
I’m a WP AER 48 fork fan. I appreciate it being lighter than a spring fork and having a lot of adjustability in my hands with a pump. And I’ve never had a failure or weird out-of-range situation with the fork due to heating up or increases in altitude or anything like that. The AER 48 holds up in the stroke very well for me and that’s important.
It’s still a ripper! The 250 SX-F loves it when you grab a handful of throttle and leave it there.
There is more feedback on small chatter bumps here and there, but in the turns and when getting through bigger roller bumps, the WP unit always works well for me. Traditional spring forks are having a resurgence, but I’m not completely convinced that KTM should go back to springs like so many other manufactures are these days. To me, the AER 48 is simpler to adjust and actually less complicated.
KTM slimmed up the bodywork and slapped on a really nice new seat this year. Our faster test riders commented on how they can slide up the bike much easier now in corners thanks to the seamless transitions in frame-to-bodywork.
Spring forks might be making a comeback, but we’re still real happy with the KTM’s WP AER 48 air forks.
Final Thoughts
If you’re in the market for the lightest, most maneuverable 250 four-stroke motocross bike, the KTM has to be at the top of your list. It is still arguably the leader in the class when it comes to the highest level of componentry on board. It has great racing legacy and a history of taking the abuse of competition in stride. For 2019, transmission components are all-new and supposedly more durable thanks to KTM’s sister company Pankl providing the goods. The diaphragm spring (DS) clutch is nice on the bigger-bore bikes, so we expect good things here, as well. And KTM’s common move to update nearly everything in pursuit of more performance ensures this bike is a better 250 SX-F than last year’s.
In the modern motocross era, no manufacturer has made bigger strides in performance than KTM. There’s no reason to think this 250 SX-F won’t continue that upward trend. CN
| SPECIFICATIONS |
2019 KTM 250 SX-F ($8999) |
| ENGINE: |
Liquid-cooled, DOHC, 4-valve, 4-stroke, single |
| COMPRESSION RATIO: |
14.4:1 |
| DISPLACEMENT: |
249.9cc |
| BORE X STROKE: |
78 x 52.3mm |
| STARTING SYSTEM: |
Electric |
| TRANSMISSION: |
5-Speed |
| CLUTCH: |
DS, wet multi-disc, Brembo hydraulically actuated |
| FUELING: |
Keihin EFI, 44mm throttle body |
| FRAME: |
Central double cradle type, chromoly steel central-tube frame |
| HANDLEBARS: |
Neken, aluminum |
| FRONT SUSPENSION: |
WP-USD, AER 48 fork, fully adjustable |
| REAR SUSPENSION: |
link-mounted WP shock, fully adjustable |
| FRONT WHEEL TRAVEL: |
11.8 in. |
| REAR WHEEL TRAVEL: |
11.8 in. |
| FRONT BRAKE: |
Single 260mm disc |
| REAR BRAKE: |
Single 220mm disc |
| WHEELBASE: |
58.5 in. |
| GROUND CLEARANCE: |
14.6 in. |
| SEAT HEIGHT: |
37.4 in. |
| FUEL CAPACITY: |
1.84 gal. |
| CLAIMED DRY WEIGHT: |
218.2 lbs. |
