THE RATHVARNA BUILD: AN IMPRESSIVE CREATION BY DARYL RATH

By Staff of Dirt Wheels

Photos by Wayne Davis Photography

HUSQVARNA 3-WHEELER PROJECT

A Husqvarna 3-wheeler? No such thing, good sir! Husky doesn’t dip a toe too far in the waters of three and four-wheeled off-road machinery. So, how did this trike come about, you ask?

Daryl Rath, the owner of Rath Racing, likes to create hybrid ATVs and ATCs. While a lot can be done to make an old machine work better than new, sometimes it is best to start off with a new ride and customize it to your wants and needs.

 

 

HUSQVARNA 3-WHEELER PROJECT

Rath’s white Husqvarna 3-wheeler began life as a 2018 Husqvarna FC450 dirt bike. This potent motocrosser has championed the AMA Supercross series and turned more than enough heads to compete at the top rung of the off-road ladder. However, Daryl stuck to his roots and managed to work his magic to turn this two-wheel powerhouse into a three-wheel track racer.

When the 50th year of the famous EDT Nationals in Ashtabula was set in Rath’s schedule, he ended up having to make a last-minute change to have a three-wheeler to race. With two weeks to go, Daryl and his crew began building the “Rathvarna.”

HUSQVARNA FC450

HUSQVARNA 3-WHEELER PROJECT

Seeing as the Husqvarna FC450 is the base of the Rathvarna’s inception, we will give you the highlights of it. This steel-framed motocrosser holds a fuel-injected, single-cylinder four-stroke motor, with a displacement of 449.2cc. The power output is an impressive 63 ponies out of the single-overhead-cam engine design.

A five-speed, sequentially shifted transmission gets aid in changing gears through a wet, multi-disc clutch. The clutch is also hydraulically operated instead of the standard cable-pull style that most ATVs come with.

Daryl upgraded only a few things on the Husky’s engine. He changed the clutch to a full Hinson setup with heavier springs that will help with the added weight and traction of two big rear tires. A Vortex ECU changed the fuel mapping, B&B Racing Engines mildly ported the head and a Robi intake system for a YFZ was installed with Rath’s custom intake mounts. Everything else was left stock on the engine.

While the main frame of the Husky remains, along with parts like the fuel tank, radiators, engine and suspension, a lot was changed out for Daryl to create an impressive three-wheel track racer. Fortunately, Rath Racing is going to offer a lot of the parts he created in a kit or separately so you can make your own conversion.  

THE KIT

HUSQVARNA 3-WHEELER PROJECT

In order to convert a two-wheel machine into a Husqvarna 3-wheeler, you must start by removing the stock rear wheel of the dirt bike and adding a swingarm with a straight axle. Rath created a 19-inch-long swingarm that utilizes Honda TRX450R geometry parts.

Once his swingarm was installed, a wide axle from Lonestar Racing was installed, along with their bearing carrier. A stock TRX rotor and rear brake caliper were utilized as well. A sprocket from Sprocket Specialties was mounted to the LSR billet sprocket hub. Gearing on the Rathvarna sits at a 14T up front and a 38T on the axle. 

Connected to the main frame is an all-new and adjustable subframe from Rath Racing. Daryl wanted the trike to corner as best as it could which means a low seat height was required. The carbureted Yamaha YFZ450 plastics sit lower than most and flow with the body of the Husky plastics so they found a home here.

Rath also wanted to source parts that are readily available, like those plastics and a Yamaha seat. A RR drop grab bar and number plate finished the rear off nicely. 

HUSQVARNA 3-WHEELER PROJECT

Moving forward, RR built a set of nerf bars for this build and had them powder-coated white by Done Rite Powder Coat, who also took care of all the paint work on the build. The next step was tackling the front end.

Rath designed and milled out a set of fork clamps that are wider than stock and hold the 48mm WP Suspension forks. They position the forks more forward than stock to be similar to a Honda ATC350X geometry. The WP forks have a forward-axle mounting design, which pushes the front wheel forward more than older three-wheelers. 

Since the stock 21-inch rim of the Husqvarna 3-wheeler would be changed out to a 10-inch DWT A5 wheel, RR created a front-wheel hub for the Rathvarna. The stock 10-inch brake rotor was now far too big to utilize on the trike, so Daryl set up the hub to accept a stock Honda TRX rotor.

He also designed a new brake caliper mount, but kept the stock Brembo front brake caliper from the FC450. A front fender from Maier was mounted up to the Rathvarna, which is made for a 1985 ATC350X. Aside from a TRX thumb throttle replacing the twist throttle, everything else from the Husky was left stock up front. 

MORE TO KNOW

HUSQVARNA 3-WHEELER PROJECT

The conversion was almost done. In order to get the Rathvarna to corner well and ride how Daryl wanted it to, he had PEP shorten the front fork length by around 3 inches. The rear setup with DWT G3 Beadlock rims and Hoosier MX tires required a shock adjustment. A part that limits the WP rear shock’s travel was installed so the three-wheeler wouldn’t be able to drag or bottom out on the frame.

We didn’t have the chance to swing a leg over the Rathvarna, but Daryl Rath is a very experienced racer and fabricator that we are happy to gather unbiased ride impressions from.

According to Daryl, the Husqvarna’s engine is extremely potent. It was one of his builds that he claimed is a powerhouse and a handful to operate. It weighs 265 pounds with a high-performance 450 engine pushing around 70 ponies now.

To put that into perspective, a built Yamaha YFZ450R generally pumps out 50 horsepower and weighs close to 400 pounds. So, the Rathvarna is one fast machine! He even told us he turned off all the traction control, so he could get the machine to stop hooking up so well. 

With the low seat height, which included cutting the seat foam down, it allows Rath to move around on the Varna with ease. It also promotes the ability to hang off the side of the three-wheeler to get the rear to slide while he is powering around corners.

The WP supple suspension cuts back on rider fatigue and is a very plush setup. Daryl managed to win a third-place podium position in the Pro-Am class at Ashtabula against over 40 other competitors on his build.

FINAL THOUGHTS

HUSQVARNA 3-WHEELER PROJECT

While Daryl loves old ATCs, he realized that parts are far too challenging to come by these days. Some old machines aren’t trustworthy, and Rath wanted a fresh build that he could easily find replacement parts for.

He created the Rathvarna in a pinch, but is now going to offer conversion kits through Rath Racing. He and his crew are currently working on building kits for other motorcycle manufacturers. You can order a whole kit from RR, or just pick and choose which parts you’d like to utilize on your own build.

We plan to try some of Daryl’s epic creations soon since we missed out on sweet seat time with the Husqvarna 3-wheeler!

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HUSQVARNA 3-WHEELER PARTS LIST

B&B RACING ENGINES: (559) 381-9700

Head mods N/A

Robi intake N/A

D.I.D RACING CHAIN: (615) 323-4020, www.didchain.com

520 ATV chain N/A

DONE RITE POWDER COAT: (320) 587-0440, www.oneritepowdercoating.com

All white parts Custom

DWT RACING: (800) 722-3746, www.dwtracing.com

A5 front N/A

G3 Series Beadlock rear N/A

HINSON RACING: (909) 946-2942, www.hinsonracing.com

Billetproof inner hub/ pressure plate kit $519.99

FSC Clutch plate & spring kit $199.99

Billetproof Clutch Cover $169.99

HOOSIER RACING TIRE: (574) 784-3152, www.hoosiertire.com

MX front 20.5×6-10 N/A

MX rear 18×10-8 N/A

LONESTAR RACING: (800) 457-7223, www.lsracing.com

Billet bearing housing $199

Billet anti-fade locknut $199

Aluminum sprocket hub $142

Axle $449

RATH RACING: (310) 234-7223, www.rathracing.com

19” swingarm $925

Front-wheel hub $375

Front brake caliper mount $129.50

Dropped rear grab bar $89.98

Sport Series nerf bars  w/ monster peg $504.95

Adjustable sub frame $650

Number plate $65

Billet fork clamps $650

Air cleaner mounts N/A

MAIER POWERSPORTS: (800) 336-2437, www.maier-mfg.com

85’ Honda ATC350X front fender $79.20 

MAXIMA RACING OILS: www.maximausa.com

Premium 10-40 oil $7.95 per Liter

DOT4 brake fluid $6.95 a bottle

Chain lube $7.50 per can

MOTION PRO: (650) 594-9600, www.motionpro.com

Throttle cable custom

PEP PERFORMANCE TUNING: (909) 477-7025

Front fork re-valve $350

SPROCKET SPECIALISTS: (800) 782-8200, www.sprocketspecialists.com

14T FC450 front sprocket $24.99

38T TRX450R rear sprocket $64.99

VORTEX IGNITIONS: www.vortexcdi.com

C10 ECU controller N/A

VP RACING FUELS: (210) 635-7744, www.vpracingfuels.com

MRX02 pale $172