Motocros Action give an exclusive look at the 2012 KTM 450 SX-F Factory Edition, the same bike that Ryan Dungey used to win the 2012 AMA Supercross at Phoenix, AZ.
Source: MXA
Lots to look at! The 2012 Factory Edition motocross bike features an all-new radiator wing shape, a thread-on gas cap (to replace the previous quarter-turn cap), redesigned airbox cover, orange powder-coated frame and a new gas tank (designed to house the fuel pump).
The single overhead cam valve train comes with lightened rocker arms, four titanium valves and high-performance springs. Also significant, is the simplicity of the design and the ultra-trick rollers on the rocker arms.
The compression ratio is 12.6:1, which comes courtesy of a new bridge-box piston, new ring design and a DLC-coated wrist pin.
The 2012 Factory Edition is not the 2013 model, that will come later this year, but is instead a race replica of the bike that Ryan Dungey will be racing. Under AMA rules a manufacturer must make at least 400 production bike before a factory team can race the bike (KTM will be bringing the bikes to the USA in 200 unit increments to meet the two AMA mandated deadlines (the first deadline is 200 bikes by March 1, 2012). It is obvious that this AMA homologation rule is seriously flawed—but what about the AMA isn’t flawed? The rule should be 400 units by January 1 of the race season, not three months into the Supercross series.
Modern metallurgy is a wonderful thing. The 450SXF Factory Edition uses the Pankl rod right out of the works bike with a solid bearing (note the oiling grooves inside the big end for lubrication).
Ryan Dungey’s get to choose between three different sets and sizes of WP works forks. The production-based Factory Edition gets WP Cone Valve fork stickers, but the forks are standard-issue WP forks. The triple clamps are black anodized.
The one-piece cast swingarm has a 25mm rear axle (previous KTM’s had 20mm rear axles). The rims are black anodized Excel Dirt Stars and the hubs are CNC-machined. The orange anodized rear sprocket is by Supersprox.
Although based on the 450XC enduro engine, the actual design of the fuel injector 450SXF engine is quite a bit different in terms of piston, crank, casting and the five-speed transmission. The case bolts are 8mm hex heads, with Torx indents built in. KTM has gone to great length to protect the electronic on the factory Edition. The significantly smaller Throttle Position Sensor (TPS) is rubber-coated and tucked in much farther than on the 2012 350SXF. Note that the starter motor now drives off of the right side of the engine. Previous 450SXF had the starter run through a transfer case on the left side. The open port in front of the 14-tooth countershaft sprocket is for the hydraulic clutch slave unit.
The front fender bolts to the leading edge of the new triple clamps.
The 2012 KTM 450SXF Factory Edition comes with Red Bull factory team graphics, orange frame, plastic frame guards, orange fork guards, orange sprocket and a gripper-style seat.
Although this Keihin throttle body may look like all others, it is actually a 44mm taper bore throttle body with a repositioned fuel injector nozzle. KTM will include the programming tool to alter the fuel and ignition maps. The software can be downloaded from KTM’s website.
The heart of any four-stroke engine is it crankshaft. KTM spared no expense on designing a new lightweight design with careful balancing and an Formula 1-derived Pankl rod..
The handlebars are taller Renthal 827 Fatbars. This is a good move because no MXA test rider ever liked the low height of the previous 672 Fatbar. The red button is actually the diagnostic light for the fuel injection system.
The look of the 2012 KTM Factory Edition includes not only new radiator wings, but also a new front number plate and front fender. The front fender is flatter across the top, but still has the distinctive KTM droop nose—the deep groove down the center of the front fender is gone. Note how the front number plate plugs into the arc of the front fender.
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