Slavens Racing KTM 300 XC-W Project

Slavens Racing installed their full list of dream parts on a KTM 300 XC-W, and we highlight which parts stand out.

Photography by Ryan Nitzen

Let’s get straight to the point: this is a dream bike. It has over $13,000 worth of aftermarket parts installed. For those of you who have the means and want the best bike on the trails, this might be it. Many of us can’t afford to double the investment in a KTM 300 XC-W, but it’s fun to dream, right? We had the chance to live that dream on some epic trails in Colorado. With a list of 31 carefully selected aftermarket parts installed, we can’t cover all of them in detail, but we’ll highlight the key upgrades we’d consider for our own bike.

Join us for this dream ride.

Building the Dream

Slavens Racing is known for providing top-quality performance parts and gear for off-road motorcycles. Jeff Slavens, the founder, has decades of experience tuning motocross and off-road bikes, dating back to the 1980s when he tuned bikes for legendary off-road champions Rodney Smith and Randy Hawkins, among others. Today, he is better recognized for his extensive library of YouTube videos discussing his “Mule” test bikes and the parts they test or develop before being sold. His focus on delivering valuable information over high production values is appreciated by countless off-road motorcycle fans who watch the videos to fine-tune their bikes.

We had the opportunity to spend two days with the Slavens team touring the facility, exploring Jeff’s personal dream garage, and riding some freshly rained-on single-track trails in the mountains above Colorado Springs. They let Ryan Nitzen (CN Off-Road Editor) and me ride this 2025 KTM 300 XC-W dream bike, and a project Yamaha YZ300X, which you’ll be able to read about in a future issue of Cycle News.

You can view the parts list with prices at the end of this story. Slavens broke things down into suspension, engine, tires, comfort and ergos and protection. We explore each category.

Suspension | Slavens Racing KTM 300 XC-W Project

We will start with the Slavens Mule MX-Tech Raven complete fork and National shock. They are handmade in the USA, and Slavens has developed its own off-road specifications to take advantage of the high-quality components. The closed-cartridge fork features Kashima and DLC hard carbon coatings, dual-compound SKF seals and billet-machined lugs. The internals of the 49mm fork tubes include shim-tunable spring seats, low-friction internal components, a compound leaf spring mid-valve, and the MX-Tech-developed Huck Valve, which offers tunable resistance at the end of the stroke. The Slavens Mule MX-Tech shock is equally impressive. It is one pound lighter than the OEM shock, has all the low-friction coatings, an 18mm induction-hardened shaft, a large reservoir and more adjustability than any shock on the market. The fork and shock come set up with valving and springs for your weight, riding style/ability, and the Slavens crew set this one up for me to provide the full experience.

I have had the opportunity to ride bikes with high-end suspension components and been impressed, but this setup provides a whole new level of comfort and performance. The bike absorbs whoops, rocks and roots like nothing I have ever ridden. I now understand why people consider it a worthwhile investment to purchase high-end suspension. With a price of $4299 for the fork and $2940 for the shock, you need to be serious about riding, but I could see having these for a bike that I plan to use for a couple of years.

Engine | Slavens Racing KTM 300 XC-W Project

The KTM 300 XC-W is slightly mellower than the XC model, and many aggressive trail riders tend to increase its performance. Slavens works closely with Two-Stroke Performance (TSP), an Australian company that knows how to extract the hidden ponies and improve the tunability. Slavens added a TSP high-compression head, which is especially helpful at the 10,000-plus feet of elevation we rode in. They also use a TSP oversized powervalve cover, which improves low- to mid-rpm power due to the added volume. A TSP ERM (ECU Reflash Module) allows you to tune your bike and comes with a tune for your specific bike to use as a starting point. The XC-W does not come with the KTM map switch that is featured on some other bikes, so a stock switch was added to enable the use of two pre-set maps. A Moto Tassinari V-Force 4X Reed Valve was fitted as part of the process of removing the stock oil injection system. A Samco Sport Radiator Hose Kit and an Extreme Parts Radiator Fan Kit help to keep the bike cool in tight conditions. An FMF Turbinecore muffler was installed, and a Rekluse Radius X 4.1 auto clutch wrapped up the performance mods for the motor.

The result? Perfect power for trail riding. It runs cleaner than a stock TBI bike, has more grunt and a more playful powerband. I didn’t feel the need to change the tuning, but with this setup, you can easily do that. I have never been a fan of auto clutches, but the setup on this Rekluse unit made me a believer. The slave cylinder provides an easy pull, and it feels like a traditional clutch but reduces the chances of stalling. I’m not a fan of mixing oil and gas, so if this were my bike, I would leave the stock oil injection system alone and deal with any added weight. Overall, however, these engine modifications make the 300 XC-W a lethal weapon on the trails.

Wheels & Tires | Slavens Racing KTM 300 XC-W Project

Tires are crucial for off-road performance, and the Slavens crew opted to use stock wheels with a Bridgestone X31 front tire and an IRC VE-33 S rear tire. Our bike featured Nuetech’s TUbliss systems, which turn the stock wheels into tubeless wheels. Tubeless tires have several advantages, such as allowing you to run low pressure for improved traction and compliance without worrying about pinch flats. Additionally, they are overall more flat-resistant but not flat-proof like mousse (foam) inserts, which come with the tradeoff of increased weight. We had perfect dirt due to rain the day before we rode, but there were a decent number of rocks, roots and rain ruts. Our tire setup, however, gave us a feeling of confidence.

Comfort and Ergos | Slavens Racing KTM 300 XC-W Project

For long days of riding, a Seat Concepts Comfort seat was installed. The stock seat seems fine until you try something better, and this seat is much more comfortable with no negative tradeoffs. The XCGear Mako 360SX bar mount helps dampen vibration and absorbs some of the hits from the trail that the upgraded, smooth-performing forks couldn’t. I have one of these on my personal XC-W and love it. Slavens installed some Motion Factory Racing flex-mount footpegs, which I thought would feel strange due to the pivoting. I was, however, surprised that they felt normal and kept my feet planted.

Protection | Slavens Racing KTM 300 XC-W Project

Finally, Slavens equipped this project bike with all the essential protective parts for off-road riding. Molecule Motorsports was selected for the skid plate, handguards, bar ends, and chain guide. Bullet Proof Designs supplied the exhaust flange guard, throttle-body guard, radiator guards, disc guard, and clutch cover. E Line   -fiber pipe guard, registration wrap, and fork guards look fantastic and offer excellent protection.

For show, the whole bike was finished with the Slavens Mule graphics kit.

Waking Up | Slavens Racing KTM 300 XC-W Project

If you ride off-road, you likely have or should have many of the items Slavens selected for this project bike. Your bike needs protection to prevent your ride from being cut short because of damage. Good tire setups are crucial for performance and fun, while comfort items enhance the riding experience. For some riders, engine modifications are optional, but they definitely make riding a well-tuned bike with a bit more power and responsiveness more enjoyable. The Rekluse auto clutch is the most expensive item on the engine mods list, but many users who have tried one will never go back to a standard clutch, and Slavens had this one set up perfectly. Suspension is the biggest investment, but if you’ve ever paid for upgraded stock suspension or had to swap out springs for your weight, you know costs add up quickly. That’s why the Slavens MX-Tech Raven fork/shock start to make a lot more sense. I found the Slavens suspension to perform better than any modified stock suspension I’ve ever ridden.

At 72 years old, Jeff Slavens has decades of tuning and riding experience, and he still rides regularly, testing parts along with the rest of the Slavens’ staff, who are accomplished riders. You can feel all that experience when you walk into the Slavens facility or talk to any of the staff on the phone. They know what works and put all that expertise into this project bike and into the recommendations they make to their customers. This is a dream bike for some or a template for those of you who can afford to add all or most of these parts at once or gradually add items over time.CN

Parts List

Slavens Racing 2025 KTM 300 XC-W

All parts can be found at www.slavensracing.com

Click here to read the Slavens Racing KTM 300 XC-W Project in the Cycle News Digital Edition Magazine.

 

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