FMF's 199lb 2008 KTM 250 SX - Crazy Light! - Dirt Rider Magazine

Passion is hard to suppress. And it has a price. It can consume you and drive you crazy. Or you can be crazy and do something with that energy. I won't comment further on the passion that fuels the guys at FMF, but when they started boasting they could build a reasonable and usable 200-pound off-road bike, I didn't doubt them; I just wanted to ride it. Starting with a 2008 KTM 250 SX and its 212-pound weight, they took off on a journey to see how low the weight could go. And they did it without doing anything crazy that would make the bike unridable or even significantly less durable; they even used an XC's 2.9-gallon tank. Because first and foremost, these guys like to ride.The chart shows the parts they replaced and the weight each part saved. And just to be sure, we lifted (easily, I might add) the bike up on a certified scale to see the number 199.0 displayed. Of course, there was only a trace of transmission fluid in the bike and just enough gas to make it run for a minute or two, and there wasn't much coolant. So you could start it and ride it at 199 pounds, but we filled the transmission and radiators and saw 199 turn to 203. Liquids are heavy and you could easily dump more than 15 pounds of fuel into this bike as well, but that's a small price to pay for a full day of fun. Plus, the more smiles you get from riding it the lighter the bike gets!The amazing thing about the bike is just pushing it around or especially throwing it onto a stand. It feels just plain feathery and lighter than even the KTM 125 SX I've been riding all year. It is the exact opposite feeling you get moving a new Husaberg around! And it's especially light feeling when lifting the rear of the bike up, likely since everything back there has gone on a serious diet.When riding the FMF KTM it has all of the riding goodness that we rave about on KTMs. First, the 250 grew to a 300 with the addition of the cylinder, head and new piston since more power is a nice partner for less weight. As it starts out light feeling already, how much of a difference do the 13 pounds make? Well, at roughly a six percent weight loss, it is noticeable in a couple of ways. The bike feels as light as any motocross bike and even lighter than a 125 some of the time. But since it is a 300, it has some power; 55 horsepower, if you're counting (and that's through a 92-decibel muffler). And power has a way of making a bike feel heavier. Yet it isn't at all heavy like a four-stroke is. But since the bike is so light on its toes, you can feel the crank spinning up, and it has an effect on the bike going from being lighter feeling than a featherweight 125 to feeling like a 250cc two-stroke MX bike when you are revving it.Where does this all come into play? Well, almost everywhere really. This bike moves forward unlike anything else. When you snap the throttle it literally hops. It feels like it leaps up off the ground. This makes a pretty big impression on the way it jumps and how it skips across bumps. Being a 300, it has plenty of pull to jump anything, and rhythm sections become much easier since the combination of weight and power is light and strong. Then there is the turning. It changes direction so easily, even when the power is on hard. On the track that means that line selection is wherever you want to go. And off-road you are tempted to pop and spring the bike around like a trials bike. Lifting the front end is simple; balancing it and controlling it, since it is so light, is easier, and changing direction takes much less effort and can be so much more sudden, if you like. Plus, there is the wonderful KTM power-valve spring that mellows the power with the turn of a tool.Light bikes can dance a little bit and also feel unsettled, especially on rocks or low-traction situations. ESP did something to the suspension (besides lightening it up!) to minimize that feeling. And it also set it up so well for both track and trail I don't know what to call it: motocross suspension that works off-road or off-road suspension that works at the track? And this was using the first-generation WP sealed cartridge fork that needed help! Then the Tu-Bliss-equipped tires built onto strong wheels allow lower tire pressures so you can even tune added compliance without fear of pinch-flats.If we were going to whine, we'd ask for the electric-start version and we wonder where the kickstand is, but that would go against the grain of this project and sound like every other story we do. It may seem impractical for every rider to go out and try to build a 199-pound bike, but through the boys at FMF you can learn a few things about weight and see some pretty easy ways to shed a few pounds off any ride. It is obvious that the shock spring and the pipe and muffler were big-ticket items that paid off in pounds, but something as easy as trimming graphics can make a subtle difference. And if they get enough requests, maybe there'll be some titanium two-stroke pipes and mufflers in the future. It's possible they might not cost much more than premium four-stroke full systems. Then when you have spare time, you can cut and trim plastic, weigh tires and drill a few holes in various locations to drop even more weight. And while you're at it, put down the beer, that doesn't help either!

The FMF crew weighed every part to see where they could shave ounces.
Then they built a titanium exhaust.
Built up the lightest wheels, sans tubes.
Just a few more pounds than Lewis...