The new 250SX-F Factory Edition engine is not only smaller, it’s 2.4 pounds lighter and more powerful. The clutch is raised 26.9mm and moved back 11.1mm. The crank was moved up 6mm and the connecting rod is 6mm shorter. The cylinder is 130 grams lighter and the camshafts are 150 grams lighter, while the finger followers have a 30% harder DLC coating. Engine changes and improvements allowed KTM to raise the rev limiter to an incredible 14,000 rpm. The clutch basket is revised, to improve oil flow and cooling, and the clutch now uses seven plates instead of eight. The 250SX-F Factory Edition uses the same 44mm Keihin fuel injection system as its 450SX-F counterpart and the Keihin throttle body no longer uses linkage. New throttle cables feature the adjusters up at the throttle tube housing. An all new exhaust system sources a 40mm shorter muffler that is 60mm closer to the center of mass.
(Above) The 2015 KTM 250SX-F Factory Edition engine is lighter and more powerful. (Middle) The new WP shock is shorter and lighter but offers up more rear wheel travel. (Below) The 2015 KTM 250SX-F Factory Edition doesn’t cut any corners and every component is top quality.
The all-new chromoly frame is lighter, featuring 20% increased torsional rigidity and 30% decreased longitudinal stiffness (identical to the 450SX-F Factory Edition minus the cradle below the engine). These changes help the frame absorb energy created from rear wheel loads and improve overall handling. The head angle is steeper and the wheelbase is 12mm shorter. A new smaller subframe is also 250 g lighter, contributing to the bike’s 7 pound overall weight savings.
Like the 450SX-F Factory Edition, the WP 4CS fork on the 250 SX-F Factory Edition received more progressive valving, aimed at adding comfort. A revised WP shock complements the frame and features a new body with a larger reservoir and a new piston and shock shaft. The shock is now 12mm shorter and weighs less. Even with the shorter shock, rear wheel travel is increased by 10mm due to the longer pull rods and a new linkage system. A rubber mount system for the handlebar is another welcome change, reducing vibration and adding to overall front end comfort. There are two mounting positions for the handlebar clamps. The lower triple clamp is designed with more flex for better handling.
A lighter airbox houses a new TwinAir air filter mounted on a cage that features a simple design to minimize incorrect installation of the filter to the cage and installation of the cage into the airbox. It is a quick install system, even easier than previous KTM models. Even the WP radiators are new, improving engine cooling by 10%. The redesigned radiator guards improve air flow and increase structural strength significantly. The new lithium-ion battery is 2.2 pounds lighter than the Yuasa lead acid battery and further reducing weight wherever possible, the footpegs and shifter are now lighter. The shifter tip prevents mud from getting into the pivot and the tip is a rounded square shape. Like the 450SX-F Factory edition, the 250SX-F features an engine map switch on the handlebar and also has an integrated launch control system.
Sitting on the new 2015 250SX-F Factory Edition is completely different than sitting on the standard 250SX-F. The seat and handlebar positions are both 10mm lower, and the footpegs are now mounted 5mm back and 4mm down, creating a bike that feels like no other KTM before it.
Compression: 15 (turns out)
L/S Compression: 15
H/S Compression: 2 turns out
The engine is very smooth and linear, with decent power delivery down low that builds so far into the upper rpms you’re not sure if the 250 engine has a rev limiter! If you like to rev an engine, the KTM 250SX-F Factory Edition is your friend, pumping out big power all the way to the crazy 14,000 rpm rev limiter. For beginners the soft power off idle can be a hindrance but once you learn to keep the engine rpms up, the power rewards are worth a little extra clutch work down low. In stock form the 250SX-F Factory Edition is more at home on an outdoor style MX track where keeping the engine singing in the rpm is easier. Changing the gearing would have the 250SX-F enjoying tighter jumper tracks with ease.
Like the 450SX-F Factory Edition, the new 250SX-F Factory Edition corners amazing. Chose an inside line, carve a deep rut or blast a berm, the 250 Factory Edition does it all with ease and confidence. This is currently the lightest production 250F, even with electric start. That lightness creates a machine that is ultra flickable and quick direction changes feel more like you’re riding a 125 than a 250F. Sometimes when a bike corners well stability suffers but that isn’t the case with the 250SX-F Factory Edition. A balanced and stable feel contributes to the great cornering characteristics, allowing the rider to enter a corner with confidence, knowing the bike will go where directed and stay in the line.
- Seven pounds lighter!
- Extremely light and nimble handling
- High revving, powerful engine
- Hydraulic clutch
- WP fork still a bit harsh in the mid stroke
- Soft off-idle power
The suspension changes keep the 250SX-F Factory Edition hooked up during acceleration and under control in heavy braking bumps. The WP 4CS fork works better than the standard 250SX-F but still exhibits a bit of the previous mid stroke harshness. Action of the 250 Factory Edition suspension is more plush and planted than the 450 Factory Edition. Compared with the standard 250 SX-F, the 250 Factory Edition’s handling and performance is vastly improved.
If all the changes to the 2015 250SX-F Factory Edition sound identical to the 2015 450SX-F Factory Edition, they should. The only difference between them is the cradle of the frames, which are slightly changed to accommodate the different displacement engines. The suspension only varies in the way of spring rates and valving. The bars, plastic, wheels, triple clamps, seat, pegs, shifter, brakes… the list could go on. The Factory Editions are essentially the same bike and feel the same, until out on the track of course. The 250SX-F Factory Edition is a better bike than the standard 250SX-F and now we can’t wait for the 2016 KTM SX-F models!