Still The Class Leader (And Looking For Competition)
Story by Trevor Hunter, Photos by Jay McNally
KTM gave their SX-F model range a heavy facelift for 2019 to mimic the changes made to the 2018.5 450 SX-F Factory Edition. Dirt Bike Test was on hand at Chaney Ranch to ride the newly updated 350 SX-F. An updated engine, chassis, bodywork, and more all makeup the 2019 machine and the feedback is positive. To start, most changes made to the bike were aimed to further reduce the weight of the bike with a claimed dry weight of 219.4lb. Some of those changes include a 200g weight reduction in the cylinder head alone along with a lighter exhaust camshaft. Additionally, the Orange Brigade switched to a PANKL 5-speed transmission while still retaining the same gear ratios after extensive testing showed improvements in both reliability and durability.
On the chassis side, a new chromoly steel frame boasts a 2% increase in longitudinal stiffness and a 10% increase in torsional stiffness along with aluminum engine hangers and a 10% stiffer upper triple clamp. The subframe is now 40mm longer than previous models and the swingarm rear axle slot is now 5mm longer allowing for the rear wheel to be positioned further back in the swingarm for better stability. In addition, a new exhaust is claimed to enhance the power along with the multifunctional mapping switch while new 12mm lower radiators and bodywork improve center of gravity and ergonomics. Also, a new seat and a new air box round out the changes to the 2019 KTM 350 SX-F. Finally, the question everyone has been waiting for – why is the frame black for the new model year? The KTM folks explained they change the frame color every year to give them something to talk about when they don’t have a completely redesigned model. Expect a grey frame for 2020 and back to the orange frame for 2021!
A common theme with the 350cc motorcycle is it sits between a 250F and a 450F and there is really no class for it. However, over the years, KTM has continued to develop the motor and close the gap between it and its bigger brother and for 2019, that gap may have gotten even smaller. The motor, while not as powerful on the bottom, has a very strong midrange before it peaks out on top as it revs on – with way more revs than a 450. We feel that on top, the 350 can run with a 450; it just takes slightly longer to get there if rolling the throttle on. But that may not be a problem as our smaller testers used to riding 125cc and 250cc bikes and even older testers in the past prefer the fun yet easy to ride motor characteristic of the 350 SX-F. With the new motor, it also allowed the rider to be a little lazier. Not being in the perfect gear wasn’t as critical as the bike could pull you out of a turn fairly quick. The Chaney Ranch Track had quite a few soft berms where burying the bike was common with the wrong line choice and even when a gear high – it didn’t seem to phase the 350 much. Additionally, the gearing on the mid-size KTM seemed to be pretty spot on on a track with both tight and flowing turns and even a few hills out of turns.
On the chassis and suspension side of things, it is difficult to tell if improvements have been made on the already good platform. The track had very minimal bumps making suspension a little less important. The track was filled with big jumps and some that were hit at high speeds and for our smaller rider, landings were a little harsh if the jump wasn’t cleared perfectly; however, it wasn’t enough to make any clicker changes and we ran the sag at 104-105mm. Our heavier rider commented that the bike had a see-saw effect where the rear end would squat coming out of turns while the front end would dive coming into turns, likely mandating a stiffer spring and more air pressure in the fork. The bottoming control was excellent for how supple the suspension feels on the little bumps so there is some progression to the setup.
Overall, KTM’s 350SX-F is a very solid platform that may finally be coming to age for lots of average motocross riders. The 350cc machine has developed into a contender even when faced against 450s–especially if compared to the first generation 350cc KTMs. Additionally, it feels very light on the track, nothing like a 450. The 1lb claimed scale weight difference over the 250F is pretty impressive – and maneuvering it around the track is a breeze. We look forward to getting some more time the new mid-size KTM for a real test on a variety of different conditions and hopefully get to back-to-back it with a 450 for another needed comparison.
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