From the moment I first clicked the 2010 KTM 350 SX-F into gear, I knew that I wanted to ride the bike off-road. Evidently I’m not the only rider who felt this urge, because ever since its introduction the 350-a purely motocross-oriented machine-has been tweaked and tuned by a number of riders for more off-road use. I’ve seen a few attempts at turning the SX-F into an XC, but to date the most successful transformation I’ve witnessed has been carried out by Stillwell Performance, a Colorado-based suspension shop run by a core group of two-wheel junkies. Not only did they trick out a 350 SX-F for full off-road performance, but they also let me race it at EnduroCross!
The company’s founder, Alan Stillwell, is no stranger to off-road racing. He’s worked with the likes of WORCS and GNCC talents Ian Blythe and Shane Watts, and under his direction Stillwell Performance is quickly becoming one of the most trusted suspension shops in the biz. Stillwell and crew are adept at tuning bikes for motocross as well as off-road, but it’s clear that their core customer is the guy who isn’t afraid to run over some rocks.When Stillwell offered me the chance to race their specially modified KTM 350 SX-F at the Denver round of the AMA EnduroCross series, I jumped at the chance. (Who wouldn’t?) One challenge that persisted, though, was that I am based roughly 900 miles away from the Stillwell headquarters in Colorado, making it tough to do much testing before the race. The upside to this was that I was able to experience Stillwell’s work from the perspective of a true customer, one who ships his suspension to the shop and then hopes that it comes back working correctly.Over the period of several weeks, Stillwell and I communicated back and forth about my weight, speed, setting preferences and riding style. When I finally arrived in Colorado three days before EnduroCross, we spent a day at the Thunder Valley Motocross track aboard a practice 350, just to get acclimated to the altitude and the bike’s power. The following morning, we headed out to a private EnduroCross track for some more serious testing aboard the race bike. This particular machine had been used as a test bike of sorts for Stillwell, but its relatively low running time and dialed-in components made it feel like a brand new bike.
Time To Ride
After all of the back and forth communication about the suspension, I was itching to jump on the KTM and see what Stillwell had come up with. Within three laps around the tricky track, it was apparent that Alan knows what the heck he is doing. I’ve ridden a lot of EnduroCross in the past five years, and I can honestly say that I’ve never jumped straight on an EX bike and had it been so close to what I wanted out of the settings. I absolutely could have raced the bike in the condition that Stillwell handed it to me, and I was already grinning over the fact that our initial setting was so close. In short, the bike had a low-in-the-rear feel that I like with good bottoming resistance on the shock, while the front end retained an active, full stroke with enough rebound to pop up and over logs. We made a few small changes to the bike’s ride height and compression (I must be scrawnier than Stillwell supposed), but overall the setting was extremely well set up.
The excellent handling of the KTM was not only a product of Stillwell’s diligent work and solid communication skills, but also due to the quality components on the bike. Race Tech Gold Valves front and rear, DLC coated fork tubes, revised spring rates, Stillwell Performance valving as well as a Race Tech Works Bladder Kit all contributed to the solid, progressive feel of the orange machine. Along with the suspension mods came a host of other additions to make the bike more EnduroCross-ready: A Scott’s shark fin-style rear disc guard and Stabilizer, Enduro Engineering handguards and skid plate, BRP clamps with Flexx bars, a Works Magura 9.0 clutch, an 18″ rear wheel with a new Dunlop MX51 tire, 13/52 gearing with an RK chain and custom graphics from Ride PG. All together, the bike and mods were priced upwards of $12,000. Surprisingly, Stillwell chose to leave the 350 SX-F’s motor alone, even sticking with the stock exhaust. This suited me just fine since I’m not super fond of rip-your-arms-out power and I don’t like to mod a motor unless I’m specifically trying to fix an issue.
After heading to the Stillwell shop to give the bike the final race-day prep, I asked Alan what exactly he thinks is the ideal EnduroCross suspension setup for the average racer. His answer might surprise you: “Specifically for EnduroCross, you have to go very far from the ‘off-the-shelf’ motocross setup,” Stillwell said. “We typically will go a bit stiffer in the front end of the bike and a bit softer in the rear. You want the back end of the bike to have a very dead feel to it where it absorbs bumps without a lot of rebound and stays down in the stroke, allowing the bike to settle through the rocks and log sections. This will actually pull the bike forward rather than allowing it to spin. In the front, you want to be stiffer on your compression and faster on your rebound. This gives the bike a lot of spring and pop as you go over logs.” Needless to say, we had the bike working great, and I was stoked for race day.
Bright and early the following morning we made our way to the track and I went out for practice. Stillwell’s 350 felt as planted and solid as it had the day before, but we stiffened up the fork a tad more due to some of the crazy-hard hits on the EnduroCross course. I felt as though the bike was super stable, so much so that I could get out of shape and still accelerate and stay in control. There were some big tire jumps and log hits on the course, and the 350 handled these with relative ease.
As far as the power is concerned, the KTM 350 SX-F is very ‘two-strokey’, meaning that you can rev it up, feather the clutch and ride it like a 250cc two-stroke rather than a thumper. There isn’t a lot of engine braking, so the entire package feels light and useable. But at the same time the engine produces excellent torque, making power in just the right place for the tight Denver EnduroCross course. The gearing we had was right on the money, and I left the bike in first throughout the entire course, only clicking second occasionally to blitz on top of an obstacle like the firewood section or the rocks.
According to Stillwell, the 350 SX-F is a perfect EnduroCross bike for a number of reasons. “It’s got the perfect blend of four-stroke chug off the bottom where it pulls very cleanly off of idle, but it doesn’t have the 450cc burst that will rip the handlebars out of your hands. It’s a very good mix, runs great in the mid-range and that’s a big part of where you’re at when you ride this bike. It’s not really overpowering and it feels a lot like a 250F, so a guy can get on this bike and have the advantages of more power and more bottom end, but feel like he’s on a smaller bike.” This is proof why a lot of off-road riders are considering the 350, even though it has been strictly branded as an MXer.
The morning practice went off without a hitch, and I even won my qualifier in the Expert class, which meant that my next obstacle was the night show. My heart jumped into my throat when I saw that I was slated to race in the first Heat of the night alongside EnduroCross star Taddy Blazusiak. I knew that it was not a matter of if but how many times he would lap me, so I just resolved to do my best and forget the rest.
The 350 SX-F puts out incredible power, and I was able to get that to the ground off the start with great traction and strong acceleration. You can see this start at the beginning of the official EnduroCross webshow (http://www.youtube.com/watch?v=L4lok0_XlZY), which shows that the 350 SX-F is competitive against and easily capable of hanging with 450cc machines. Unfortunately, my luck ran out after about 100 feet when I dropped the front wheel in a hole and went over the bars, which left me pinned under not one but two bikes. I remounted and was able to keep going, but at this point Taddy had all but lapped me. I’m telling you, that dude is an animal!
EnduroCross heat races are six laps, but they feel more like 30 when you’re out on the track. The positive side to the longer motos is that I was able to see exactly how the bike worked when I was dog tired. Here, just as Alan had predicted, the useable power delivery of the 350 SX-F served me well and I was able to make my way around the track without working too hard and wearing myself out. The aftermarket clutch was an absolute blessing, and I was fortunate enough to save some energy for the upcoming semi race. Once again, the bike pulled a solid start but not quite a holeshot, and the suspension continued to work to my advantage in the really rough sections. By this point I was pretty well beat and definitely off the pace, which left me watching the nail-biting main event from the sidelines (and I was perfectly OK with that!)
When it came time to give the 350 SX-F back to Stillwell, I was more than a little bummed. This machine seems to have the perfect combination of usability and performance, traction and delivery, damping and balance. The suspension setup made the motorcycle feel like it belonged to me, a feeling that I honestly don’t achieve very often given the wide variety of bikes that I race. But more than anything, I came away from the test impressed with Stillwell’s skills as a tuner. It’s not easy to dial a bike in over the phone, throw together settings for a rider you’ve never met and then tune the whole package to work on an incredibly brutal racetrack, but that’s exactly what Alan did. As a customer, I would have been completely satisfied with the revised suspension, and the extra components on the 350 SX-F were just icing on the cake. Perhaps the only bad part of the test is that I’m now stuck between trying to set up Dirt Rider’s 2010 350 SX-F for off-road and just waiting for KTM to produce a 350 XC. But so far as I can tell, that just might be a win-win scenario!To learn more about Stillwell Performance and to chat with Alan about dialing in your bike, check out www.stillwellperformance.com, or call 866-460-0896. For more info on EnduroCross go to www.endurocross.com. See you at the races!