MXA’S 2012 KTM 250SXF MOTOCROSS TEST: DID KTM GRAB FOR TOO MUCH OF THE BRASS RING?

December 11, 2011
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Q: FIRST AND FOREMOST, IS THE 2012 KTM 250SXF BETTER THAN THE 2011 KTM 250SXF?

A: No. Electric start does not make a bike go faster; it just makes it start easier.
 
Q: WHAT CHANGES WERE MADE TO THE 2012 KTM 250SXF?

A: Before we jump headlong into the list of 2012 changes, it’s worth mentioning that last year’s KTM 250SXF underwent four major updates. The biggest mods on the 2011 model were made to the shock linkage, electronic fuel injection, chassis and engine. MXA wasn’t expecting the 2012 model to be new from the ground up?and we were correct in our assumption. KTM did, however, focus on six areas of concern.

(1) Electric starter. Surprise! Not really. KTM was, and still is, the only manufacturer of the Big Five to outfit their motocross-specific four-strokes with electric starters. The 450SXF and 350SXF have push-button starting, so it only makes sense that the 250SXF would come equipped with the button. Not altogether different from the 350SXF unit, the 250SXF shares the same starter motor and battery. KTM sells an optional kickstarter through their PowerParts catalog (their offroad version of the bike, the 250XCF, comes with the button as well as a kickstarter). The electric starting system adds 5 pounds to the overall weight of the 2012 KTM 250SXF.

(2) Mapping. As has become commonplace on all EFI-equipped bikes, the 2012 250SXF has different ignition and fuel-mapping options. KTM coined the acronym EMS for “Engine Management System,” which is a fancy term for electronic fuel injection (EFI). Mapping on the 250SXF has been adjusted to increase performance in hot conditions. There are also two additional preprogrammed maps; one for more hit and one for less. You need an optional KTM switch to easily move between the three available maps. On a good note, the throttle position sensor (TPS) is now rubber-covered. It was the source of many headaches in 2011.

(3) Suspension. KTM spec’ed the same spring rates as in 2011, but they changed the valving for better low-speed performance and improved bottoming resistance. New oil and dust seals by SKF are also standard, as well as new bushings with an improved Teflon coating for more durability.

(4) Engine. Although the engine internals are exactly the same as in 2011, KTM revised the shape of the air boot for improved airflow.

(5) Rear brake. The Brembo rear master cylinder has a different piston design to improve seal reliability.

(6) Body styling. The 250SXF has new graphics, the rear fender has reinforced ribs for greater rigidity when lifting the bike off the stand, and the Renthal handlebar pad is new.

2012 KTM 250SXF: KTM made mapping, valving, and graphic changes to the 250SXF. Of course the big news is the electric starter, which is borrowed technology from the 350SXF.   

Q: IS THE 2012 KTM 250SXF ENGINE BETTER THAN THE 2011 KTM 250SXF ENGINE?

A: To put it bluntly, no. The 2012 KTM 250SXF isn’t an improvement over the 2011 250SXF. We could say that it is a step backwards. The MXA wrecking crew lauded the 2011 model for its improved powerband, crisp fuel injection and precise handling. Given that the 2010 KTM 250SXF had very little low or mid-power, the EFI was solely responsible for beefing up the punch. KTM claims that their goal was to add even more low and mid for 2012, but somehow the plan backfired. Instead of adding more bottom-end oomph and midrange surge, the Austrians created a slower revving, bland powerband.

Q: WHAT OTHER PARTS OF THE 2012 KTM 250SXF PLAN BACKFIRED?

A: There were two other MXA gripes.

(1) Weight.
In 2011, the KTM 250SXF got heavier because of the addition of fuel injection and the linkage rear-suspension system. For 2012, the KTM 250SXF gained weight again because of the electric starter (and its battery and drive gears). Once the lightest 250 four-stroke made, the KTM is now the heaviest. The 2012 250SXF tipped MXA‘s scales at 231 pounds. Yikes! That is backbreaking weight for a deuce-and-a-half thumper. Ask yourself, would you prefer to have the 15 pounds back or the EFI, linkage and electric start? And we thought new technology just added to the price; we didn’t know we’d be paying by the pound.

(2) Suspension.
KTM is a weird company when it comes to suspension settings. They historically choose the wrong spring rates, and, unlike other brands, their smaller-bike suspension works worse than the suspension on their big bikes. We weren’t all that happy with last year’s 250SXF suspension settings?and we aren’t happy with the 2012 settings. Most MXA test riders came to terms with the WP units after changing the shock spring and lowering the fork-oil height. With a weaker engine, heavier weight and borderline suspension, the 2012 KTM 250SXF is overshadowed by previous models.


Once you get the suspension dialed in, you can enjoy the handling?which is spot-on.

Q: HOW DOES THE 2012 250SXF COMPARE TO LAST YEAR’S MODEL ON THE DYNO?

A: Maximum horsepower on our 2012 KTM 250SXF was 35.52 ponies at 10,800 rpm. Maximum torque was 19.43 foot-pounds. Compared to our 2011 KTM 250SXF, the 2012 engine made one horsepower less at peak and lost nearly half of a foot-pound of torque. That is going in the wrong direction.

The KTM 250SXF was the perennial leader in ponies among all 250 four-strokes?until last year. We aren’t criticizing KTM for giving up its previous top-end-only powerband for more midrange?that is what they needed to do (even though their carbureted engines produced close to 39 horsepower at peak). Their carb-equipped KTM 250SXFs had been chastised over the years for having linear powerbands that were only impressive around 13,000 rpm. They not only lacked bottom and midrange, but personality too. The old-school, high-rpm KTM 250SXFs were difficult to ride. The switch to fuel injection moved their power to where it needed to be, but it cost them too peak ponies in the process. KTM is no longer the horsepower monger that it once was. So long, pony boy!

Q: HOW FAST IS THE 2012 KTM 250SXF?

A: Fast is a relative word. We don’t think that the 2012 KTM 250XF is slow, but it feels slow. It makes competitive horsepower for its class (albeit at the lower end of the scale). And, the power it does makes is very unassuming. Every MXA test rider, regardless of skill level, noted the slow-revving powerband. Although we knew that the 250SXF could churn out sufficient horsepower for the job, it was sluggish under acceleration. At no point did the Austrian powerplant show signs of aggression, even when we switched to the aggressive ignition map.

We were befuddled. KTM didn’t make any serious revisions to the inner workings of their 250SXF engine. So what happened? We blame the revised mapping and reshaped air boot. By trying to gain bottom-end hit and midrange power, KTM neutered the overall powerband. Test riders were left searching for solutions to the lackadaisical powerband on the 2012 KTM 250SXF. Since optional mapping changes didn’t help, we added a tooth to the rear sprocket to help liven up the engine. Eventually, we found solace in aftermarket exhaust pipes.

How fast is the 2012 KTM 250SXF? It is competitive, but to ride the 250SXF effectively requires feathering the clutch, gearing it down and holding the throttle wide open. Thankfully, the Brembo hydraulic clutch can handle a Mike Tyson-style thrashing.


For fast or fat riders the KTM needs a much stiffer shock spring.

Q: WHAT DO WE THINK ABOUT THE ELECTRIC STARTER?

A: Electric starters are double-edged swords. On one hand, the push of a button makes it simple to start the bike, even in the most dire situations, such as after stalling the bike while racing. Conversely, an electric-starter system packs on the pounds. An extra 5 pounds of mass added to the 250SXF is unwelcome weight. Several companies sell lighter batteries, but it’s hard to justify spending a hundred dollars or more on a part after dumping beaucoup bucks on the initial investment.

The MXA wrecking crew was split down the middle in regards to the button. Half were in favor of easier starting, while the other half detested the additional weight on an already heavy bike. Last year’s bike didn’t have any trouble starting, so why did KTM equip the 2012 250SXF with an electric starter? Probably because of the success of the 350SXF and 450SXF E-starters. Since it was a success on the big bikes, they naturally assumed that an electric-start 250SXF would give them brownie points in the marketplace. They were certainly right with the big-bore Katooms, but the downside on the 250SXF is excess weight, which unfortunately is piled on top of additional weight gains from EFI and rising-rate linkage. Having said that, it’s hard to return to a kickstarter after simply pushing a button to bring the 250SXF to life, but it is equally hard o give up five pounds on a bike that is easy to kick over.
 

 
Ponies: The 250SXF powerplant pumps out 35.52 horsepower, which is a 1/2-horsepower decrease over last year’s engine. We think the mapping and air boot are to blame.


Power-up: KTM is the first manufacturer to outfit a production 250 moto-specific four-stroke with an electric starter since Husky tried it a couple years ago.

Q: DOES THE 2012 KTM 250SXF PASS THE AMA AND FIM SOUND TESTS?

A: KTM’s engineers are champs at passing the FIM’s two-meter-max sound test (the Japanese manufacturers have trouble with it). But, there are currently two sound tests.

(1) Two-meter-max. The FIM tests bikes with the throttle wide open and the sound meter 6 feet away. A bike passes if it produces 115 dB or less.

(2) AMA sound test. The AMA tests bikes with the sound meter at 20 inches and the rpm reduced to 4500 rpm for 450s and 5000 rpm for 250s. A bike passes if it produces 94 dB or less.Starting next year, the AMA will adopt the FIM’s two-meter-max sound regulation. KTM doesn’t care about the rule change, because they are one of the few motorcycle manufacturers to pass both the AMA and FIM tests. Our 2012 KTM 250SXF blew 113.0 decibels in the two-meter-max test and 93.6 dB in the AMA test.

Q: HOW DOES THE 2012 KTM 250SXF HANDLE?

A: One of the greatest attributes of the 2012 KTM 250SXF is its precise handling?with one caveat: the mismatched fork and shock. An unbalanced bike never handles up to its potential. In stock trim, the 250SXF fails to settle into corners because the 48mm closed-cartridge WP forks have too much oil to allow the suspension to use its full travel effectively. The forks deflect violently, and the energy from hitting every bump is transferred directly into the handlebars. It’s an unpleasant sensation. As in the past, the MXA test riders lowered the oil height and found bliss with the handling. On the rear end, riders over 160 pounds will need to go up on the shock spring rate to balance the bike and prevent the rear from bottoming.

The 250SXF works best around fast outside corners, as opposed to inside lines. The chromoly steel chassis responds well to rider input, and testers could change directions without any wiggle. The KTM 250SXF isn’t the best-handling bike in its class, but it can hold its own. It would, of course, be better if it were lighter.

Q: WHAT ARE MXA’S RECOMMENDED KTM 250SXF FORK SETTINGS?

A: Here is what the MXA wrecking crew ran in its 2012 KTM 250SXF (stock settings are in parentheses):
    Spring rate:
0.46 kg/mm
    Oil height:
365cc (380cc)
    Compression:
9 clicks out (11 clicks out)
    Rebound:
10 clicks out (12 clicks out)
    Fork leg height:
5mm up
    Note:
When the forks are new, they need about an hour of riding to them break in.

Q: WHAT ARE MXA’S RECOMMENDED KTM 250SXF SHOCK SETTINGS?

A: Here is what the MXA wrecking crew ran in its 2012 KTM 250SXF (stock settings are in parentheses):
   Spring rate: 5.4 kg/mm (5.1 kg/mm)
   Race sag:
102mm
   Hi-compression:
2-1/4 turns out (2 turns out)
   Lo-compression:
14 clicks out (15 clicks out)
   Rebound:
14 clicks out
   Note:
The shock is very sensitive to race sag.

Q: WHAT DID WE DO TO MAKE THE KTM 250SXF WORK BETTER?

A: We found happiness in the 2012 KTM 250SXF after making these four changes:

(1) Shock spring. The stock 5.1 shock spring is grossly undersprung for anyone over 160 pounds or faster than a Novice. Jumping up a spring rate is a must if you fit in either of these categories. As is, when the soft shock is mated to the harsh forks, it creates an imbalanced.

(2) Lower the fork oil height. KTM must have drums of fork oil sitting in their production facility. Why would we make such an assumption? For years, the 250SXF has been plagued with far too much fork oil in the 48mm WP units. This wouldn’t be a big deal, except for the fact that the overabundance of oil causes a serious case of midstroke harshness. The MXA wrecking crew has learned to eradicate the problem by pumping out 15cc of fork oil from the air-bleed screw (reference the August 2011 issue to learn how to properly lower fork oil height). Decreasing the oil level is a simple and free way to vastly improve the performance of the forks.

(3) Drop the weight.
In the past two years, the KTM 250SXF has ballooned from under 215 pounds to over 230 pounds. The 2012 KTM 250SXF has the unfortunate distinction of being the heaviest 250 four-stroke only two years after being the lightest one. We don’t see a solution for this problem. The shock linkage added weight (and it isn’t going away), the fuel injection added weight (and it isn’t going away) and the electric starter added weight (KTM sells an optional kickstart kit if you want the battery, starter and drive gear to go away).

(4) Add a pipe. We hate KTM’s exhaust pipe, but not for the reason you think. KTM’s engineers designed a one-piece pipe that is less expensive to build because it has no slip-fits whatsoever. What do we hate about that bit of money-saving engineering? We can’t remove the pipe without unbolting the shock. From a power perspective, KTM’s one-size-fits-all pipe design isn’t as effective as the tapered and multiple tube diameters of aftermarket pipes. Thus, aftermarket pipes work better?and you don’t have to remove the shock to remove the aftermarket pipes.

(5) Reprogram the map.
We put the 2011 “aggressive” map back into our 2012 black box and managed to get back a quicker rev and more active feel. To do this, you need KTM’s software package.


The stock bars are too low. We opt for Renthal 603 FatBars.

Q: WHAT DID WE HATE?

A: The hate list:

(1) Weight. This bike is a porker! At 231 pounds, the 2012 KTM 250SXF is by far the heaviest 250F on the market. The electric starter made it easier to start the bike, but be careful what you wish for.

(2) Engine. The 2012 KTM 250SXF powerband is boring. Not good in a girlfriend?or a race engine.

(3) Suspension. It’s not that we detest the WP suspension, but we hate having to swap spring rates and lower the fork-oil height every year. D‚j… vu?

(4) Overheating. Beware of the 250SXF boiling over. On several occasions, radiator coolant burped out of the overflow hose while the bike idled on the starting line. This is the first time we have encountered such a malady with the KTM?and contrary to one of their stated goals.

(5) Gearing. We geared the bike down (going from a 49- to a 50-tooth rear sprocket), and it spiced up the powerband. Adding two teeth was overkill.

(6) Handlebars. We aren’t fans of the stock handlebars, because the bars are too low. MXA rest riders either run KTM’s 5mm taller bar mounts or switch to Renthal 603 Windham-bend FatBars.


KTM used to be the ugly duckling of the motorcycle world. Now, they are super attractive…save for the front fender.
 
Q: WHAT DID WE LIKE?

A: The like list:

(1) Handling. Have steel frame, will turn. Once the suspension is dialed in, the chassis works well through corners and rough stuff. The KTM chassis is proof that not every manufacturer is drinking the aluminum-frame Kool-Aid. We’re thankful.

(2) Looks. The 2012 KTM 250SXF looks fast, even when it’s sitting on the stand. We especially like the sublimated graphics, which wear like iron.

(3) Clutch. All hail the Brembo hydraulic clutch! The lever pull is as smooth as butter, and it handles feathering, dragging and excessive abuse with ease. Every bike should come with a hydraulic clutch.

(4) Brakes. Every test rider raved about the brakes. The Brembo units have serious pucker power. Good stuff?the best brakes of the Big Five.

(5) Triple clamps. Although the bar mounts are too short for taller riders, the four-way adjustable triple clamps are perhaps the best in the business. The torque settings are even etched into the aluminum clamps! Very cool.

(6) Rims. Last year, the Excel rims were soft. KTM fixed the issue in later production runs, as well as on the 2012 model. We didn’t have any issues with the rims.

Q: WHAT DO WE REALLY THINK?

A: Engine performance, weight and suspension are the most important attributes of any 250 four-stroke. Those are the ABCs of 250cc race bikes. KTM seems to have failed the class; it is as though they studied their history books before taking a mathematics exam. Snappy power, light weight and balanced suspension are the remedial classes that the KTM engineers need to take before 2013.

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