2005 KTM 250 SXF

MotorcycleUSA Staff | May 11, 2005
2005 KTM 250SXF - Wallpaper

Don’t fret KTM fans and factory riders. The 2005 250 SXFs are on their way. Granted, they are on a slow boat from Europe, in the middle of the Atlantic Ocean as we speak, but they’ll be on dealer floors by June 1. And rest easy my friends – they are pretty darn good.

We came to both of these conclusions on a recent trip to Perris Raceway in Southern California for KTM’s press introduction on their newest and, arguably, the most researched and developed motocross bike in its lineup, the 2005 KTM 250 SXF. The Austrian manufacturer took its sweet time developing the bike because, plain and simply, they had to make it good. Heck, when there are already several manufacturers making a 250cc 4-stroke motocrosser to measure yourself against, you have no choice but to make it right and have no excuse if you don’t.

A brief look at the history of the bike shows that the project’s been going for a few years, and quality works bikes emerged in the World Championship Motocross GP Series last season. The bike was good enough to help propel Ben Townley to an MX2 World Championship in `04. In America, things have been much the same with only team KTM factory riders getting a chance to ride and race several of the earliest production models that made it over a few months before the ’05 AMA Supercross season started. Things went pretty well here, too, with Nathan Ramsey and Josh Hansen winning five 125cc SX races between themselves.

KTM lovers and the factory riders have had a legitimate reason to fret the last six months because the production bikes simply aren’t here yet. For the loyal KTM fans, it’s frustrating because they just want their new bike, but it also means they’ll be getting a better bike when they finally get to fork over the cash. As for the KTM factory racing team in America, things are a little more serious. In order for the bike to be homologated, and therefore legal for AMA racing competition this season (and past SX season), 400 ’05 units must be available on dealer floors by June 1.Theoretically, if the bikes don’t make it, Ramsey and Hansen’s five 125cc Supercross wins would be…invalid? Well, we don’t know what the AMA would do and don’t really even want to imagine. Let’s just hope there are no freak storms in the Atlantic this month.

KTM s goal was to design a fast  reliable 250cc 4-stroke motor that is easier to maintain than what is offered by the competition.
KTM’s goal was to design a fast, reliable 250cc 4-stroke motor that is easier to maintain than what is offered by the competition.

So on a rainy day in May at Southern California’s Perris Raceway, MotorcycleUSA got to sample KTM’s new machine. The author and MCUSA tester Mikey Mandahl (5’8″, 160lbs, Intermediate) spent most of the soggy day splashing around a shortened version of the swamped track. The conditions weren’t prime for testing or photos, especially in the morning, but by the end of the day the track had dried up enough for us to get a pretty good impression of the bike. Let’s just say it was well worth the wait.

Tech Talk

When it came time to design the 250 SXF, KTM’s Scot Harden, Tom Moen, and a host of R&D guys from both here and Austria were not shy about telling us that the motor received much of the attention. Their goal was to design a fast, reliable 250cc 4-stroke motor that was easy to maintain compared to the competition. The spark plug is easily accessible from the side of the motor without having to remove the tank, the carburetor can be easily loosened and twisted in the intake boots for jetting purposes (without removing the seat and tank again), the oil is easy to change with only one drain plug, and the valves are supposedly easy to adjust due to an inclined cam cover. We don’t actually know if they succeeded or not on the ease of maintenance because we haven’t had to live with the bike, but we can at least tell you that it is fast.

In theory, 4-strokes are supposed to keep consistent, accurate valve timing at all rpm. In reality, many machines’ timing changes slightly as the revs scream up to the upper ranges of the powerband. KTM worked hard on the entire valvetrain to cut down on variations in timing and create a good spread of power. This was accomplished with the use of an intermediate gear to reduce the cam chain length, a hydraulic cam-chain tensioner, and a separate, one-piece cam housing. The end result was a compact DOHC motor with a bore and stroke of 76mm x 54.8mm, four titanium valves, a 39mm Keihin FCR-MX carburetor, a 6-speed, close-ratio transmission, and a dry weight of 52 pounds.

The new swingarm is one pound lighter than the swingarm on other SX models.
The 250 SXF features a one-piece, cast-aluminum swingarm that is claimed to be 25% more rigid and a pound lighter than the swingarms found on the rest of the SX models.

The chassis was specifically built for KTM’s 250cc 4-stroke motor, and like the rest of the Austrian bikes received this year, the chromoly frame utilizes oval tubes down by the swingarm pivot sections for a claimed 30% increase in rigidity over past models. KTM engineers found that as they stiffened the frame elsewhere (like near the headstock), the swingarm pivot area would continue to twist due to the linkageless, offset-to-one-side rear shock. This bike also features a one-piece, cast-aluminum swingarm that is 25% more rigid and a pound lighter than the extruded-aluminum swingarms found on the rest of the SX lineup this year. Since KTM owns Husaberg, it took a few years to perfect the sweet cast-aluminum swingarms on the ‘Bergs before slapping them on the off-road EXCs and MXCs in ’05. They look very trick and will be standard on all KTMs in ’06 and.

The remainder of the bike is typical KTM, which means high-quality, race-ready equipment. Like the rest of the SX lineup, the bike features WP suspension components (48mm fork), a Magura hydraulic clutch, Renthal 608-bend tapered aluminum handlebars and grips, Excel wheels, a billet-aluminum tripleclamp that is adjustable for handlebar position and offset, and a Regina chain. Bridgestone’s older M59/M70 intermediate terrain tires are mounted front and rear, respectively.

The bike also comes stock with a trick quick-turn gas cap that works much like a radiator cap (but easier); with a quarter-turn twist, the cap comes right off. Just in case you’re wondering, this is a revised version from the one that popped off of Josh Hansen’s bike and poured gas onto the track in one of the early SX rounds. And last but not least, this is the first KTM 4-stroke to have a handlebar-mounted hot-start lever and no manual decompression lever. The hot-start lever is now mounted on the Magura clutch perch. KTM did not want to hear about how riders had to reach down to the carb and then back on a quick restart. 

KTM s newly designed gas cap offers easy access with a quarter turn.
The gas cap is simple but very cool and can be removed with just a quarter turn; much like a radiator cap. Attention to detail is one of the reasons KTM remains at the forefront of motocross design.

On The Track

As we waited for the track to dry out in the morning, we couldn’t help but notice how trick and clean the KTM 250 SXF looked. The bike is striking and the cast-aluminum swingarm looks mean and nasty in the best of ways. The fit and finish are excellent. After shooting our still photos, Mikey couldn’t take it any longer and suited up. Heck, somebody had to start making lines and letting the mud fly.

The angular-looking tank design had Mikey worried when he threw his leg over the bike for the first time, but the worries soon faded as the bike felt nice and skinny and very easy to move around on. Some of the KTM factory riders thought the bike was actually too thin in the mid section and ran wider aluminum tanks during the AMA Supercross season. It felt great to us. Did you ever think you’d see the day that people would complain about motocross bikes being too thin?

After a few laps figuring out what lakes… I mean puddles, to miss, Mikey started to pick up the pace. The motor picked up nicely and quickly on the bottom and midrange especially, and pulled very well up to the rev limiter at 13,500 rpm. Vibration was very low even though the motor doesn’t use a counterbalancer. KTM claims that the bike puts out 39 horsepower at 11,000 rpm, and we have no reason to doubt that number. From what we’ve heard, 39 horsepower is about what most heavily modified Japanese 4-stroke 250s put out.

If you re happy and you know it  click your heels!
Mikey Mandahl fell in love with the KTM and got comfortable enough to start throwing down heel-clickers in the middle of testing.

We felt that the snappy motor would make the bike a standout at supercross tracks. The broad spread of power enabled test riders to either shift a little early and use the low to midrange power, or rev it out and let it scream up top. The 6-speed transmission shifted nicely, but first gear is rather low and didn’t get used too much. The stock gearing is 13/48, so riders who go to a 49 or 50 for tighter tracks and quicker response will probably never touch first gear. Conversely, the low first gear will make it a versatile trail machine in the tighter stuff. And desert guys can just throw on a 14-tooth countershaft sprocket for a higher top speed and race off into the sunset.

Our test riders had nothing but praise for the suspension performance on the KTM 250 SXF. “Some people complain about the harshness of KTM’s rear suspension and I just don’t understand why,” Mandahl said at one point during testing. “I cased a few things on purpose and it sucked them up perfectly. It does feel a little different than bikes with linkage but you get used to it really fast.” If anything, the rear suspension does transmit a little more harshness to the rider over braking and acceleration bumps, but its ability to gobble up the big hit evens things out. It works well – it just feels different. We didn’t feel the need to make a suspension adjustment all day. 

The bike handled very well and could take just about any corner we threw at it. Whether it was a flat and slick corner, a mud-filled rut, or a cut-and-thrust berm, the 250SXF was right at home. We think the stiffer frame and swingarm have really helped things out because this is the best-handling KTM we’ve ever ridden. We did get the bike to headshake just a little, but it was at the end of a fifth-gear pinned straightaway with big braking bumps leading into a berm. We concurred that just about any bike would headshake a little at those speeds and in those choppy conditions.

The strength of the Euro coupled with a weak dollar makes the price tag on the 250 SXF a bit pricer than the Japanese competition. The price is set at  6 398 here in the states.
The strength of the Euro coupled with a weak dollar makes the price tag on the 250 SXF a bit pricer than the Japanese competition. The price is set at $6,398 here in the states.

The Brembo brakes are nice and powerful and worked great all day, even when caked with mud. They seem to engage a little quicker and more powerfully than the Nissin brakes that come on Japanese bikes, but they work well and you get used to them very quickly. As mentioned earlier, the fit and finish are excellent and the controls are all right where they need to be. Everything just feels right, and the Magura hydraulic clutch is amazing, never needs adjustment, and is very easy to pull in (one-finger easy).

The only problem with this bike is the limited number of units that will be coming to America this calendar year – about 1000. They are good bikes but they might be hard to get. Perhaps some guys dropped off the waiting lists because they were tired of waiting and wanted a new bike. The Euro is killing the dollar right now so the bikes are a little pricier than the Japanese competition. At $6398, they are $200 more than the CRF250R, $700 more than the YZ250F, and $600 more than the Kawasaki/Suzuki 250 4-strokes.

So are the new KTM 250 SXFs worth the wait and the extra money? We think so, especially if they are easier to maintain and/or you already ride a Honda (which is close in price). If you like orange, go for it, you won’t be disappointed. “I want to sell my Yamahas and get one of those,” was all I heard Mikey saying as he left.

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