Cycle News - Archive Issues - 2000's

KTM 4sO SX OYerYiew Of the five bikes in this shootout, the KTM features the fewest changes from last year. The swinSarm, however, is new and the shock and fork received some new circuitry. The rear-brake mas- ter cylinder was also updated. The motor took on mostly dumbility enhancements, such as beefing up the valve guides and stiffening up the crank- shaft. The FCR4I carburetor is, howev- er, brand-new. The KTM is the onb/ bike here not sporting an aluminum frame, instead relying on more traditional chrome-moly steel to hold ever),thing in place. The subframe, however, is constructed out of alumihum. Like the Kawasaki and Yamaha, the KTM is fitted with a four-speed gearbox, but, unlike the rest, its clutch operates hydraulically, the others cable-actuated. The KTM's suspension is also unique in that the rear shock bolts directly to the swin8arm, eliminating thoie pesky linkages. KTM still claims that the shock's internal PDS damping system achieves the same action as do linkages but with- out the added weight and maintenance. At one time, the fiM was the only production MXer of the Big Five to come with aluminum handlebars - that advan- tage is now long gone. But it still affe6 quality tapered aluminum bars, Magura controls and Brembo brakes. The Good, The Bad ard The Orange With the stunning record of its late 2005-release, double overhead-cammed 250SX-F, you might think that KTM would have been anxious to send the sin- gle-cammed 450 SX design to the crush- er in favor of a DOHC 450. Well, not yet. The single-cammer is still with us, and it ain't so bad. Powerwise, the SX didn't exactly thrill the maiority of our crew lt seemed like everybody took their iabs at the orange bike. Our pros felt that it simply doesn't offer enough hit compared to most of the other bikes in the shootout, and that it is a bit slower rewing than most of the other bikes too. The pr€vailing feeling was that the KTM has a willing midrange with a less than willing top-end if you want to flog it like that. Less heroic testers didn't so much mihd the power delivery as they did the vibration that seems to creep out of the engine and into the bars and pegs. One other curi- ous comment was that almost all of our riders felt that the KTM has a tendency to enSihe brake more than others. Some didn't like that, while others didn't care. All felt that they speot more time shifting the KTM from second to third gear than they did with the other four-speeds and, in fact, with ory of the rest of the group. But at least the tranny is smooth, and the SX's hydraulic clutch is awesome as usual. And one other thing: Kudos to KTM for actually making a fire-breathing 450 with a fairly civil exhaust note. All others should follow suit immediately! One area where the crew was Lrnani- mousl/ positive was with regard to the KTM's turning manners. 'Awesome inside turning, like nothing else," said one. Another opined, "The KTI4 is the best cornering bike in the shootout." True, no other machine aPPeared as ready to carve a corner as the 450 SX, and only one tester rated it as average. The KTM's strength appears to lie in its ability to drop in very quickly and plant itself in a rut or around a berm, holding the line. The KTM's straight-line stability remains up close to par with the most stable machines in the shootout, as well, A couple of testers reported some twitch in the front end, but they didn't seem to make as big an rssue of it as they did with the Honda. The SX's suspension was also rated as very good by our non-pro testers, thoush one pro who had never ridden a KTIY before immediately began com- plaining about how the PDS rear end tends to "blow through" its travel- The same rider called out the KTH as having harsh fork action under most conditions, but another pro simply labeled the fork as "not outstandinS" while praising the rear by saying, 'A lot of grjys say bad things about that shock without the linkage, but I didn t have any problem with it." Like its turning manners, the Kff4's brake performance fostered solidarity among our ranks. All felt that rhe SX's front and rear brakes flat smoke the rest of the bikes in this shootout. ln the past, KTMs have been criticized for being overly sensitive, and this has been most- ly with reSard to its two-stroke machines. On the big four-strokes, how- eve( we'll take power over feel any day, and the 450 SX delivers mondo stoppinS power. "Once you get used to 'em, they're the kind of brakes you want," one tester said. Ergos were a maxed ba8 on the KTM, according to our testers. Some complained that the seat was the worst on any of the bikes in the shootout. They said it is too soft, which is 180 degrees removed frorn KTM'S Technoselseats of days gone by. Still others said that it is too easy to snag your legs on the KTM's radiator shrouds, which do appear to be rather wade when viewed from the saddle. 2006 450cc Four-Stroke Motocross Shootout Main let - 185 Pilot let - 42 Needle - OBDTP (4) FueUAir Screw - I l/2 turns Recommended Ride Height - l05mm ENGlNE....447.92cc liquid-cooled sinSle- cylinder four-valve DOHC fou.-stroke BORE & STROKE .--.--95mm x 63.4mm COMPRESSION RAT1O.............. I 2.0: I CARBURETOR ..Keihin 4lmm MX FCR lGNlTlON............Kokusan diShal 4K-3A CLUTCH..............Hydraulically operated TRANSMlSSlON ................Four-speed FINAL DRIVE ..#520 chain (non-sealed) FRAIIIE..............................Chrome-moly (aluminum 7020 subframe) FRONT SUSPENSION ........W8 48mm irwerted, fully adlustable REAR SUSPENSION ......W8 PDS non- linkage, fultT adiustable FRONT-WHEEL TRAVEL.....-.-,- I 1,8 in. REAR-WHEEL TRAVEL ............ 13.2 in. FRONT BRAKE ............Sin81e, 260mm, Brembo w/ twin-piston caliper REAR BRAKE ..Single, 220mm. Brembo w/ single-piston caliper GROUND CLEARANCE .......... I 5.0 in. wHEELBASE ......,.......................s8.3 in, CLAIMED DRY WE|GHT..........23 I lbs. FUEL CAPAC|TY..................-----. 1.9 tal. KTM 450 SX MSRP .$6998 SEAT HEIGHT 36.4 in. 18 JANUARY]I,2006 . CYCTE NEWS D I Chrome.moly.steel frame w/ aluminum subframe SOHC 4-valve valvetrain Titanium valves Four-speed transmission Wet sump Suspension - WP Fork - 48mm WP USD Aluminum tap€r€d handlebars Tires - Bridgestone Nonslip seat \ tr I ir I lt t/ ..r- /l\ rlr( SPECIFICATIONS r?

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