- Single cylinder, 4-stroke
- 4 gears
- Keihin FCR-MX 41
- 449.3 L
- Top Speed:
- 110 mph
KTM worked their magic on the biggest 2009 SX-F model, the MX1-destined 450 and, like on all other racing bikes, it all stands in the details. The retuned engine is claimed to provide a healthier rush across the powerband while chassis and controls updates are aimed at improving handling as the rider is supposed to feel more at home on the new model than on the previous one.
Feedback provided by the 2008 model year showed no need for a fuel injection system yet so the 449.3 cc, liquid-cooled, single-cylinder, four-stroke engine remains carbureted. Still, modifications to the engine improve the low end rush, just as a fuel injection would have. The electric started motor now works with a lighter new piston and a new cylinder head. This last change required the updating of the valve train as well while intake and exhaust ports have been reshaped in an attempt to complement for the lack of fuel injection.
The front fork is totally new and claimed to ensure smoother landings as the spring and valves are more up for the task which also decreases the quantity of oil in the fork. While the shock was upgraded too, we can’t help noticing how KTM concentrated on delivering a different front end feel due to the multitude of changes found there. They’ve added hand-clickers for compression settings while the front brakes feature all-new components (a new master cylinder, caliper, caliper mount, pads as well as lever). The clutch lever is also redesigned so that the rider would be more in control over his ride and concentrate on lap times.
This is how the Austrian’s manage to keep the 2009 KTM 450 SX-F among the most competitive bikes out there despite the fuel injection frenzy that got into the Japanese manufacturers.
The 2009 Honda CRF450R is one good such example as the 449cc, liquid-cooled, single-cylinder, four-stroke engine features the advanced Programmed Fuel Injection system with 50mm throttle bodies. Sharp handling is ensured by the Progressive Steering Damper so there’s plenty for the Honda to work with both against European and Japanese alternatives.
In this case, Yamaha’s 2009 YZ450F stands out for being powered by a 449cc, liquid-cooled, DOHC, four-stroke; 5 titanium valves engine that is fed through a Keihin FCR MX39 carburetor. Yamaha dirt bikes are known for being both aggressive and competitive so it’s a fair battle with the 450 SX-F.
Suzuki is all about fuel injection for their four-stroke, liquid-cooled, DOHC engine powering the RM-Z450 as the bike is the first fuel-injected one to win in AMA Supercross Racing so it proved well capable.
Like the Yamaha and KTM, the 2009 Kawasaki KX450F features a carbureted, liquid-cooled 449cc, four-stroke, DOHC, four-valve single-cylinder engine so it’s Green vs Orange vs Blue in 2009?
Quite possibly, but we shouldn’t forget about KTM’s fierce competitor, Husqvarna. In this case, the corresponsive model is the 2009 TC 450, also an upgraded model with healthier response at low revs. Overall weight has been reduced with 1 kg so the liquid-cooled 449cc, single-cylinder, four-stroke engine fed through a Keihin FCR-MX 41 carburetor would have to carry less of the bike’s own weight. No electric starter for this Husky as weight saving is drastic.
While all of the previous mentioned manufacturers stick to aggressive panels and pretty simple decals, KTM goes the whole way and sticks on the new 450 SX-F virtually everything that could go through a future owner’s mind. The bodywork is aggressive and yet refined while the stickers on the mudguards, swingarm, fenders and forks enhance the racy look of this motocrosser in a much greater way that those on the side plates alone could have ever managed.
A rare thing on motocross bikes, mudguards are there too. We totally appreciate the blacked-out silencer as well as the narrow seat (positioned at 38.78 inches from the ground) and we can’t help noticing how good the Excel (21-inch front and 19-inch rear) wheels look especially fitted with the petal-style discs.
The critics would most likely say that it looks like a rolling cartoon, but the SX-F is big, impressive and means serious business.
This is what we’ve come to find (not that we ever doubted) when riding the ’09 model year so the Japanese crowd can start worrying as the KTM 450 SX-F might be one of the quietest dirt bikes out there, but it’s also faster and sharper, definitely superior to the previous model year.
The first things that you notice are the new controls, but there’s really much more to it. Actually, the entire front end feels much lighter and implicit easy to work with. The riding position is aggressive and fairly demanding so it needs a little bit of getting used to, but not in the case of professional riders. In fact, KTM built the new 450 SX-F so that it would satisfy both the riding demands of the average dirt bike rider and highly experienced racers and the bike soon starts unveiling this big quality.
Soon, we’ve come to find that the engine makes no exception in that concern as during the worm up laps it proved very lively in the low and mid rpm range. It isn’t the kind of motor that delivers the very best of it only when highly revved so it is a refined four-stroke with a taste for equal power spread all across the powerband. Instant throttle response is always there, the front end lifts and there’s nothing to stop any enthusiastic dirt bike rider with a fair number of riding hours behind his back from having fun.
Handling feels easy, almost natural thanks to the front end being lighter. The thing leans fast into corners and with the rear end responsively following the front. There really isn’t anything to complain about it apart from the fact that the seat is a little bit too high (nothing strange on this type of bikes though) and the electric starter only works with a top notch battery.
Landings are very smooth as we’re dealing with 11.81 inches of wheel travel up front and 13.19 inches at the rear and the bike is very flick able so you’ll always find it easy to direct it on the exact needed trace in order to position for the soon following corner. The new brakes are highly effective and stopping power is always more than enough as the bike only weighs 230.6 lbs.
We really thought that we’re gonna complain about the four-speed gearbox, but we didn’t felt the need for a fifth one as there is a lot of power to compensate for that and the Austrian bike ends up being just as good as bikes that are fitted with five-gear transmissions. The clutch works smoothly and both clutch and brake levers are easier to grab with only two fingers.
Hot or cold, the engine will always start even if it will take you through the kick starting routine if the battery isn’t there to support an electric start. The chassis ensures superb handling and it all culminates in this dirt bike’s ability to turn any average rider into a pro.
KTM didn’t rebuild the new 450 SX-F from the ground up, but all the ’09 refinements not only ensure it remains a strong player on the dirt bike arena, but an actual indicator of where things should head towards. A fifth gear won’t harm anyone and I guess we could live without the e-starter just so that more weight would be saved. Or couldn’t we?
Engine and Transmission
Engine type: Single cylinder, 4-stroke
Displacement: 449.3 cc
Bore x stroke: 97 x 60,8 mm (3.82 x 2.39")
Compression ratio: 12.5:1
Starter: E-Starter/12 V 4 Ah
Transmission: 4 gears
Carburetor: Keihin FCR-MX 41
Control: 4 V / DOHC with finger followers
Lubrication: Pressure lubrication
Engine lubrication: Motorex, SAE 10W50
Primary drive: 29:74
Final drive: 14 : 52
Cooling: Liquid cooled
Clutch: Wet multi-disc clutch, operated hydraulically
Chassis and Dimensions
Frame: Central double-cradle-type 25CrMo4
Handlebar: Renthal, Aluminium Ø 28/22 mm
Front suspension: WP-USD Ø 48 mm (1.89")
Rear suspension: WP PDS shock absorber
Suspension travel front/rear: 300 / 335 mm (11.81 / 13.19")
Brakes, front/rear: Disc brakes 260 / 220 mm (10.24 / 8.66")
Rims, front/rear: 1.6 x 21"; 2.15 x 19" Excel
Tires, front/rear: 80/100-21"; 110/90-19"
Chain: 5/8 x 1/4"
Main silencer: Aluminium
Steering head angle: 63,5°
Wheel base: 1475 ± 10 mm (58.07 ± 0.38")
Ground clearance (unloaded): 380 mm (14.96")
Seat height: 985 mm (38.78")
Tank capacity: approx. 8 liters (2.11 gal)
Weight (no fuel): approx. 104.6 kg (230.6 lbs)