2011 KTM 250 SX-F Comparison

JC Hilderbrand | February 21, 2011

KTM is one of the machines that bring a lot of excitement to this year’s competition. Austrian engineers have obviously been planning this bike for a while as it sees major changes on all fronts: engine, chassis, suspension and bodywork, many of which coincide with the larger KTM 350 SX-F and KTM 450 SX-F. Compared to last year the 250 gets better marks in all the categories it struggled in and it’s an improved machine that offers a ton of features.

First off, the SX-F gets a Keihin fuel injection system like the 350 which has temperature and altitude compensation along with cold-start enrichment. Trading jets for injector was a popular move with our testers but there is more to the new engine. Switching to the Keihin system required a stronger electrical output so the alternator was beefed up to compensate. KTM reworked the cylinder head with dual-overhead cams and DLC-coated finger followers that are said to increase flow by 10% at the intake port. The bike gains six pounds over last year’s model, but the engine gets added character down low while keeping it’s high-rpm performance.

2011 KTM 250 SX-F Comparison
2011 KTM 250 SX-F Comparison
The 2011 KTM 250 SX-F is basically new across the board. The engine takes on fuel injection and the PDS shock has been replaced with linkage.

KTM’s torque dominated on the dyno with the highest peak output of 20 lb-ft and a curve that overtakes all the others at 5000 rpm. It signs off just a bit in the final few thousand rpm but the EFI clearly helps boost the SX-F’s bottom end. The same goes for the horsepower comparison where the orange line clearly stands above the rest on our dyno graph. Overall horsepower is third highest, but the 250 peaks at 10,600 rpm while the others need to keep climbing to find their limits. During acceleration testing the SX-F struggled despite its impressive power. We attribute this to gearing and wheelspin. A six-speed transmission has very close ratios and requires a bit more shifting.

Like last year, the KTM has a quiet demeanor. A reading of 92 decibels from the muffler keeps things easily under the AMA limit. With so much development going into the new bike, we were hoping for electric start as well. It’s one of the things we love about the bigger KTMs and so it’s almost expected on orange bikes these days. Hey, we’re spoiled by the Austrians, and we like it. Fortunately, the new engine is capable of retrofitting with an electric starter which is available in the KTM Hard Parts catalog. Also, now that the SX-F is fuel injected, a tuning tool is also available.

There’s been an awful lot of bitching about KTM’s PDS shock over the years. It’s been a major point of contention between believers and nonbelievers, to a degree where we’ve seen consumers, media, test riders and racers all beg for the switch to a traditional linkage design. This year they all get their wish. Like the 350 and 450 SX-F models, the 250 gets KTM’s new WP suspension with linkage in the rear. Up front is a closed-cartridge 48mm WP fork with revised internal settings. There were several complaints about the new shock kicking over rough terrain. Even though our testers were heavier on average than the target 250F rider, KTM has its smallest SX-F set up closer than the larger machines. Some of our testers were very happy with the WP performance and it didn’t get chastised for being extremely soft despite our size. The switch away from PDS was a major move and often times the hype is beyond reality. The new shock/linkage combo is good, but it will continue to get better with more development.

Some riders like the way the KTM frame flexes, but our speedy old-timer, Lewis, thought the only non-aluminum chassis in the test was too soft and holds back its handling. It’s worth noting, however, that Lewis posted the fastest lap time of the test on the KTM (lap times are not included in the scoring and are for additional consideration only). Not all of our testers pointed specifically at the Chromoly frame, and another vet rider claims it handles the best. But the KTM falls behind the Kawasaki, Honda and Suzuki which were all heavily praised for their on-track behavior.

2011 KTM 250 SX-F Comparison
Kyle Lewis (pictured) posted the fastest lap of the test on the KTM, despite having some issues with the handling.

KTM always leads the way with extra tidbits of racing goodness like Renthal grips and the hydraulic clutch, but it gets even more race-ready for 2011 with upgraded wheels. Front and rear Excel A60 rims and CNC aluminum hubs combine to shave almost a pound, and the aluminum swingarm, aside from being ridiculously good looking, weighs almost a pound less than the old version. All of our testers appreciate the KTM’s race pedigree.

There isn’t anyone in our test who doesn’t think the KTM has a fast engine. EFI adds smoothness, immediate response and the KTM sacrifices only a few pounds in the transition. The WP suspension is better than last year, but still not the best overall package and we had some handling issues. With all the new technology, KTM boosted the price to $7699 ($400-550 more than the others) and once again it’s become the expensive bike. Regardless, it still has incredible brakes and has the best features. For 2011 it lands in fourth, but it’s the best KTM 250 we’ve tested.

2011 KTM 250 SX-F Rider Impressions:

JC Hilderbrand – 5’11” – 177 lbs – Novice
This 250F has big-bike power delivery. It feels just like the KTM 450 SX-F engine all the way through the rev range, but with less power, obviously. I’m not sure if I like that. I appreciate the hydraulic clutch on some levels, but generally the feel is too vague for me so I really wanted more hit out of the engine to avoid having to use it so much. It’s definitely fast though. Sometimes I thought this was the best engine in the test and other times it seemed to lack some personality. One thing’s for sure, the other bikes have lulls or flat spots somewhere in the powerband, but not the KTM, it makes consistent power everywhere.

This is the best KTM fork I’ve ridden with yet. I liked it right away and had good success with minor adjustments. Usually KTM’s have a light, nervous feeling on the front end at higher speeds, but the 2011 doesn’t headshake like I expected. The WP fork definitely overshadows the new rear end, which is just ok for me. It doesn’t do anything badly, but it feels a little dead and I’m not convinced it’s better than last year’s. However, the bike handles very well. It’s not quite as nimble as the Suzuki or Honda, but it’s right in the middle. My biggest problem is that it’s hard to hold onto – not with your hands, because the grips are awesome, but with your legs and boots. The seat is super slick and the new bodywork is almost too sleek. The first thing I would do is put a different gripper seat cover and that should handle most of it. Otherwise the details put the other bikes to shame. Love the A60 rims, air-filter access and even the engine is easy to get at. In a test this stuff doesn’t really matter, but it’ll be huge when owning the KTM.

2011 KTM 250 SX-F Comparison
2011 KTM 250 SX-F Comparison
2011 KTM 250 SX-F Comparison
Multiple riders weren’t satisfied with the new shock, but overall the suspension package is still solid

Nick Thiel – 6’1” – 175 lbs – Intermediate
I have a great time riding this bike because the motor is like a tractor – it revs slow but keeps pulling and pulling. The componentry on the KTM is always top notch. The hydraulic clutch is awesome and the brakes are great. The bar bend they use is wide and a bit swept back for my liking, but that’s a quick fix. The suspension is solid but not impressive and I think it actually worked better without the linkage. It just got real nervous in high speed situations which didn’t inspire a whole lot of confidence. Maybe with another year of testing it will be better.

Tod Sciacqua – 5’8 – 170 lbs – Vet Expert
I wasn’t comfortable with the whole ergonomics of it; it’s not like a Japanese bike. The new linkage suspension doesn’t feel like it makes any difference. If anything the old style PDS feels like it hooks up more coming out of corners and on starts because it squats down and stays squatted, so it makes better traction. This year it vibrates a lot in the bars and the suspension is harsh. I think it could be a decent bike, but would need to spend enough time really getting it set up for me.

Brian Chamberlain – 6’0 – 190 lbs – Vet B
I came into this test with very little time spent on KTM’s and came away very impressed with the 250 SX-F. This bike really fits me well and I felt the most instantly comfortable on the KTM. The relationship of the bars, pegs and seat really suit my size and riding style. The bars are nice and wide and all of the controls are very natural.

I really enjoy the motor on the KTM as well, especially on the tighter and jumpier tracks. Power delivery is very smooth all the way through the rev range. While the power seems to fall off just a touch on top, it has a decent bottom-end and a strong mid-range. I also think the bike revs quickly which adds to its ability to build power.

Handling is also very confidence-inspiring. I’m impressed with how easily and predictably the bike turns in. It reacts well to input and carries itself well though all types of corners. I never experienced any type of headshake or uneasiness from the front end. The suspension is also much like the Kawi. The fork is a little harsh on the initial part of the stroke, but is able to absorb some huge hits really well. Some compression adjusting got the fork feeling better, but in the end it’s not quite where the Honda fork is. The shock works well for me and it also soaks up big landings and small, high-speed chatter and braking bumps.

Fit and finish of the KTM is top-notch. All of the body-work really came together nicely and small perks like tool-less air filter removal just added to my list of cool features. Components on the KTM are second to none, including the buttery hydraulic clutch and super cool hubs and rims.

Chris See – 5’10” – 165 lbs – Pro
This bike feels the most unique of any bike I have ridden, but unique in a good way. The rider cockpit is very open with lots of room, even though I favor a tight cockpit with close controls. This machine also comes with great features for your money. On the track this bike had the best brakes and clutch feel that I have felt on a bike – they work top-notch all the time. Also the engine works well from the bottom end power and the way through to the top end, which made it two thumbs up in my book.

2011 KTM 250 SX-F Comparison
Plenty of riders will be seeing this angle of the 250 SX-F in 2011.

This brings to the suspension which is a major thing for me. On the fork I went softer all the way around. Once the shock’s high speed adjustment was slowed down about one full turn it was where I like it for when the track starts to develop some actual bumps. The rear end of the Katoom still has a nasty little spike that I could never get rid of. It makes me a little nervous about going through some rougher sections and is a big part of the reason why I put this bike third.

Kyle Lewis – 5’10” – 180 lbs – Vet Pro
This bike has a strong motor, it just signs off way too soon – plus the transmission spacing is very close. I spend a lot of time shifting and I feel like I’m in the wrong gear a lot of the time. This chassis has too much flex for me when I get really aggressive with it. It has a wallowing feel through high speed corners (not as bad as the 450), and I have to work hard to get it to turn tight.

For me the suspension just has too much movement. It was a little harsh up top, but after that it would push through too fast to the bottom of the stroke. I felt the small acceleration and braking bumps which I normally don’t on a KTM – they are normally plush up top. I loved the brakes and clutch on this bike. The other manufactures really need to take a look at the Brembo brakes and the hydraulic clutch system, but I missed the happy button!

JC Hilderbrand

Off-Road Editor| Articles | Hilde is holding down the fort at MotoUSA’s Southern Oregon HQ. With world-class dirt bike and ATV trails just minutes away, the hardest part is getting him to focus on the keyboard. Two wheels or four, it doesn’t matter to our Off-Road Editor so long as it goes like hell in the dirt.