At the end of every model year, I never want to give up the one bike that I’m most attached to. It should be noted that the bike I choose to ride is not an endorsement of what MXA thinks is the best bike—it is just the bike that, given my druthers, I choose to race (when not forced to race a different bike). So, as every model year ends, I always refuse to return my old bike to the manufacturer out of fear that the new bikes won’t suit me as well. For most of the last five years, I’ve okie-doked Yamaha about MXA’s YZ250 two-stroke when the time came to return it. Most of the time my effort was foolish, because a YZ250 from 2006 is virtually identical to a YZ250 from 2010, thus I wasn’t holding on to precious metal.
My YZ250 strategy changed in 2009. During the year, I was busy testing a wide variety of bikes and had little time to race the YZ250 because, in truth, it didn’t need much test time (since it was unchanged). I had finally drifted away from two-strokes, not because I wanted to, but because business called. In 2009, when I had the freedom to race what I wanted, I almost always chose to ride the
2009 KTM 450SXF.
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| The white fork guards are stock Honda CRF parts. They fit on the KTM’s
WP forks, but you have to use Honda bolts. |
For me, it was an odd choice. It was as far away from a two-stroke as any bike sold, and strangely enough, pretty distant from the typical four-stroke it competed against. But, I grew to admire the four-speed Austrian thumper—in no small part because I had taken the time to fine-tune out the aspects that I didn’t like. This silk purse modification program endeared the 450SXF to me because I felt more kinship with it. Before I get to the 2010 KTM 450SXF, I need to update you on what I did to my 2009 KTM 450SXF
I geared it taller. I know that this is the wrong way to
go on a four-speed, but for me it worked. In essence, I changed the
four-speed into a three-speed. I started in first gear, shifted to
second, and stayed there for everything that wasn’t a quarter-mile long.
You can’t do this on a five-speed...and I became very adept at not
shifting.
(1) Gearing. I geared it taller. I know that this is the wrong way to go on a four-speed, but for me it worked for me because I'm not as fast as I once was (and I was looking for some trick to make me go faster without trying too hard). In essence, I changed the four-speed into a three-speed. I started in first gear, shifted to second, and stayed there for everything that wasn’t a quarter-mile long. You can’t do this on a five-speed...and I became very adept at not shifting.
(2)
Height. I lowered it as much as possible. I ran a 15mm lower seat (KTM P/N 773-07-040-200), had the subframe cut-down 5mm, and had Bones Bacon shorten the shock (which allowed me to slide the forks up and maintain the same geometry).
(3) Suspension.
I took off the stock WP suspension components and swapped them for Showa A-Kit components. Luckily, Pro Circuit needed to run a test program on their Showa kit for KTM. They gave me the job and a chance to run $7000 worth of exotic suspension parts (www.procircuit.com).
(4) Exhaust.
I ran a DR.D exhaust system, and I had Doug Dubach modify it to fit on my cut-down frame (www.dubachracing.com).
(5) Battery.
The stock battery was replaced with an accessory 4.6 amp KTM battery that weighed 2 pounds less. It came from the KTM parts department and had a shocking $500 price tag. The part number was P/N 773-11-053-100 (www.ktm.com).
(6) Gas cap. I clipped the locking tabs off of my gas cap, cut hand holds into the side panels with a box cutter, swapped to white UFO plastic and had DeCal Works make custom MXA graphics (www.decalmx.com).
So, when KTM handed MXA our brand-new 2010 450SXF, I refused to give them my 2009 bike back. I knew that I had to put in a lot of saddle time testing the 2010 KTM 450SXF, but I wanted to keep my personalized 2009 450SXF as a bailout bike.
Guess what? Once I raced the 2010 450SXF, I never raced my 2009 model again. Oh, don’t get me wrong, I still wouldn’t give it back to KTM. I fully expected that once the honeymoon was over with the 2010, I’d want to race my trusty ’09 again. It never happened!
Although I was busy splitting my time testing the CRF450, YZ450F, KX450F and Husaberg FX450, I somehow managed to finagle the chance to throw off whichever hapless MXA test rider was assigned to the 2010 KTM 450SXF at regular intervals.
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| The wheels are from QTM and use Talon hubs, Takasago rims and orange
Bulldog spokes. |
As a rule, MXA keeps its bikes in stock trim until all of the bikes have been tested and the shootouts completed. We do make mods that fix flaws, but we don’t hop-up our test bikes for the simple reason that we are testing them the way they sell them (not with $2500 worth of extra fluff added on). But, once we are through with the production test cycles, every MXA test rider is free to try to improve the bike of his choice with whatever it takes.
The 2010 KTM 450SXF is a lot better than the 2009 four-speed—and not just because it has five speeds. My oddball gearing in 2009 worked well for me, but KTM’s five-speed gearbox is virtually perfect when it comes to gear ratios and gear spread. I was also impressed that KTM had shortened the shock for 2010, but I had already done that in 2009. What I couldn’t do to my 2009 was lower the frame by 10mm (although KTM didn’t lower the 2010 subframe as I had in 2009). To my way of thinking, the 2010 KTM 450SXF was a very refined version of my four-speed 2009 450SXF.
But living with a KTM is different from just slapping parts on it. Here are my tips for spending hang time with the 2010 KTM 450SXF version of the orange monster.
(1) Gas cap.
I hate the locking gas cap. Yes, I know that they had a gas cap fall off a few years ago in the 250 West, but I had my pants fall down once when I forgot to tighten my belt buckle and I resisted the urge to use a padlock after that. I cut the locking tabs off the KTM cap and, if I do it perfectly, the gas cap still clicks on, but can be removed without pressing the button with your other hand.
(2) Airbox.
Never take a new air filter and stick it in the bike. Nope! You have to reach around behind the cage to make sure that the filter is actually seated perfectly. MXA has sucked enough dirt behind poorly installed KTM filters to build a sandbox.
(3) Side panels.
I have no intention of picking my bike up by the edge of the rear fender. Not only is it painful, but it is plain wrong. I cut the side panel away to expose the rear of the subframe.
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| The MXA wrecking crew has tested Showa, Fox Factory, Ohlins and Race
Tech shocks. The one thing we have learned is that the KTM prefers a 7.6
kg/mm spring over the stock 7.2. |
(4) Top shock bolt.
It has the bad habit of trying to escape. Check the top shock bolt and the shift lever bolt before every race if you want them to be there later.
(5) Battery.
Last year I ran a small KTM battery. This year I switched to a 2.5-amp TurnTech battery (www.turntechbattery.com). It is a Lithium iron phosphate (LFP) battery and weighs 2.75 pounds less than the KTM small stock version. TurnTech makes a 5.0-amp battery if you don’t think 2.5 amps is enough, but I had no troubles with the little battery. The big TurnTech battery is 1.75 pounds less than the stocker. The 2.5-amp TurnTech battery retails for $99 (which is $400 less than what last year’s small battery cost).
(6) Suspension.
I like the stock forks. They aren’t as good as the Showa A-Kit forks I ran last year, but they are good enough for someone of my speed. As for the shock, I have run Showa, Fox, Race Tech and Ohlins shocks. I liked the Ohlins shock the best. It was very supple. The Showa, Fox and Race Tech shock all had issues that bother me (either too harsh or too soft, but never just right). Once I switched to a 7.6 kg/mm shock spring I had no issues with the stock WP shock.
Five years ago, the bike came with a 6.6 kg/mm spring.
MXA ran a 6.9. The next year, KTM installed a 6.9 on the production
bikes and we ran a 7.2. Then, KTM moved to a 7.2 kg/mm spring and we
went to a 7.6. What’s the deal? We think that KTM is willing to go
stiffer on the spring rates, but someone at the WP factory sabotages the
spring changes by lightening the damping to keep the bike exactly where
it was with the lighter spring.
(7) Shock spring.
KTM has done a weird dance with its spring rates. Five years ago, the bike came with a 6.6 kg/mm spring. MXA ran a 6.9. The next year, KTM installed a 6.9 on the production bikes and we ran a 7.2. Then, KTM moved to a 7.2 kg/mm spring and we went to a 7.6. What’s the deal? We think that KTM is willing to go stiffer on the spring rates, but someone at the WP factory sabotages the spring changes by lightening the damping to keep the bike exactly where it was with the lighter spring. If you want my advice, run a 7.6 spring on your stock 2010 WP shock (if you are over 175 pounds). On my Showa, Ohlins and Fox shocks, I run a 7.5 kg/mm springs.
(8) Seat.
I still run a very thin seat (P/N 773-07-040-200). Hey, my legs are short, and I need to get my toes closer to the ground. I should mention that KTM’s super thin, low-profile seat is not comfortable.
(9) Subframe.
Even though KTM shortened the shock and lowered the frame, I still cut the subframe down. I lowered the subframe by 5mm at the bolt hole, which brings the back of the rear fender down almost 15mm. I should mention that I cheated when it came time to weld and drill the subframe—I stole Mike Brown’s already cut-down subframe instead. Sorry, Mike.
(10) Wheels.
KTM has great wheels, but since I needed a spare set I went whole hog with a set of Talon hubs laced to Excel rims and tied together with powder-coated orange Bulldog spokes (and spline-drive nipples). The wheels cost $644.95 for the front and $744.95 for the rear (www.qtmi.com).
(11) Exhaust.
I don’t need more peak horsepower from the KTM 450SXF, but I did want more oomph off the bottom and through the midrange. I chose to go with a stainless steel DR.D system (www.dubachracing.com). It is inexpensive at $615.00 and has a very unique look.
(12) Clutch.
I love the hydraulic clutch. I am a clutch abuser (a leftover habit from my two-stroke days). Even though the KTM hydraulic clutch requires a firmer pull than most spring clutches, it lasts twice as long. When it comes time to rebuild it, the KTM will accept KTM 450SXF, Honda CRF450 or Kawasaki KX450F fiber plates. I tend to think that the Honda plates are better.
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| DR.D’s KTM 450SXF exhaust swoops up under the gas tank. The tube-like
resonance chamber is used to improve low-end power and knock one decibel
off the sound output. |
The “MXA Air Force” graphics are custom made by DeCal Works (as are the
number plate backgrounds).
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What would I change if I could change anything else about my 2010 KTM 450SXF? It would be easy to say "nothing," but it would hardly be true since I changed boatloads of pieces. In a lucky break, the 2011 KTM 450SXF is downsized, flatter and more diminutive than the 2010 model.
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