ATV PROJECT: DUNCAN RACING LOBO TRX305R

Dan Mayer’s second time around By the staff of Dirt Wheels, Photos by Pat Carrigan

We were fortunate to shoot Dan Mayer’s Duncan-built, Lobo-chassis TRX305R quad as soon as it was finished. Pro racer Josh Row thumbed the throttle.

It is an old story: parents, trying to do what they think is best for their kids, forbid the purchase of an ATV. Often, as is the case with Dan Mayer, quads become the forbidden fruit and a life-long obsession is born. This Duncan Racing 2018 Lobo-chassis build is the latest milestone in Mayer’s dedication to magnificent quads.

It turns out that Mayer was a die-hard Dirt Wheels reader as a youth, and he was drawn to the radical builds. When he could finally afford his own dream build, he went for it. As it turned out, it took some time and two trips across the continent before it happened.

Mayer lived in wild and free Arizona as a kid. Riding opportunities abound in that state, and even though he wasn’t able to own a quad, he did ride both quads and dirt bikes. He still owns both types of machines, and they are all two-strokes! Eventually, his family moved from Arizona to the East Coast. He was crushed to learn it was a part of the east with no place to ride.

As he grew older he did some woods racing in the east, but he longed for more open spaces. The opportunity came to move back to Arizona. Before he even moved, he shipped his Banshee from the East Coast to Duncan Racing for his first radical project build—a desert Banshee.

Mayer describes the Banshee as a work of art and one he loves to ride. The problem came when he rode a TRX250R. He became convinced that the Honda was a better mount for rough desert riding, and he eventually owned 1987, 1988 and 1989 versions. Parts of the ’88 and ’89 went into this build.

“I’d been told that the Doug Roll Lobo full chassis is incredible,” Mayer explained, “but I didn’t know what to expect. With the addition of the Duncan 305cc PC 2000 power-valve motor, I knew this machine would be fast. On the first ride, I quickly learned how combining the best two-stroke chassis ever produced and a custom motor with decades of R&D creates an extremely well-balanced machine.”

QUALITY OF BUILD

It is a resounding vote of approval for Duncan Racing that Mayer signed up for a second machine from these famous builders. Mayer agrees, and for good reasons: “The overall build and finishes are top-notch. From custom-fabricated heel guards to the quality of the chroming and polishing, nothing was missed. They are absolutely the best builders in the industry. Loren and Leonard are passionate about the industry and take care of their customers. They have a great team!”

Obviously, the starting point was tracking down a Doug Roll Lobo complete MX chassis. Even if you are eager to sign up for the $19,000 Lobo rolling chassis package, Roll doesn’t just pop these babies out or have them stacked on a shelf. Mayer was fortunate to find  a full Lobo kit that another person had already started. In particular, the kit had been fitted with a $3500 Beringer billet brake kit that includes every part of the brake system. All of the major components are whittled from blue-anodized billet aluminum. The brake kit also includes the rotors, but not brake lines, so Duncan Crown-series lines were added. It also has a Beringer billet clutch perch.

The Roll complete Lobo chassis kit includes the frame, subrame, stem, swingarm, A-arms and the Elka shocks. It is very complete.

SO COMPLETE!

This Lobo chassis is sold as a complete assembly. It includes the frame, subframe, A-arms, steering stem, Elka Stage 5 shocks (front and rear) and a swingarm!

You do need to add spindles and hubs, and Mayer selected Roll billet TRX front hubs. The final front-end width is 50 inches including the tires.

The Roll swingarm does not need to employ a linkage. In addition to the hubs (stock from Mayer’s donor quads), the rear of the machine needs to be completed. Mayer and Duncan chose an RPM Dominator 49-inch axle. RPM also provided the bearing carrier and anti-fade nut. All three shocks are not merely off-the-shelf, but are customized by Roll Design for each build and owner.

At that point the Lobo wasn’t actually a “roller.” A Sunstar steel sprocket joined the rear disc on the axle, and both were joined by Hess Motorsports rotor and sprocket guards. Hess guards are “toothed” around the perimeter, so they can actually drive the quad forward if stuck on logs or even rocks.

Next,  the chassis needed something to roll on. OMF beadlock wheels wrapped with 21-inch front and 20-inch rear Maxxis Razr2 tires. Mayer has found that the rough terrain he rides in Arizona needs more clearance, so he is considering taller tires.

Pro Josh Row was happy to play on the Lobo TRX. It was easy to leap from the top of this dune. The landing was soft.

FILLING OUT

What looks like stock plastic is actually OEM-style from Maier Mfg. FourWerx Carbon fills things out with a tank cover for the IMS 4.0-gallon tank, a hood and a seat kit. Duncan filled out the chassis with its own custom heel guards, a chrome front bumper and an engine skid plate.

Before the chassis made final assembly, the subframe and upper A-arms were chromed. For contrast, the frame, swingarm and lower A-arms were powdercoated. The prettied-up parts were joined with a titanium bolt kit that included the swingarm pivot bolt.

Up front a Precision steering stabilizer was mounted. Above that are an anti-vibe bar clamp holding a Tag CR Hi tapered bar with ODI grips. Bolstering the Beringer levers is a thumb throttle with a polished billet cover. A Pro Design tethered kill switch maintains space on the bar as well.

Baja Design Squadron Pro lights, an LED taillight and RS 200-watt stator make up the DR-fabricated custom stainless steel lighting mounts for all of the lights.

While the frame kit is complete, Mayer still needed the RPM Dominator axle, bearing carrier and anti-fade nut. The rear uses stock hubs.

Very little of the stock TRX engine remains. Aftermarket parts replace the intake, exhaust, cylinder, head, piston, clutch and gears! Left: A carbon cover hides the IMS tank. Lighting (front and rear) is from Baja Designs. That blue billet clutch perch and lever are from Beringer.

“MOTORVATION” DEPARTMENT

Mayer sent Duncan a complete TRX 250R engine to work with. It was treated to a complete engine tear-down and rebuild with few of the stock parts returning. Those stock parts that remain were cleaned, checked and usually refinished. To start, the engine cases were powdercoated black. The crank was rebuilt with a rod kit and new bearings and seals. Not trusting the stock gearbox, it was enhanced with Yukon heavy-duty gears. The clutch basket was set aside for a Hinson billet basket and a Duncan clutch kit. The outer cases are stock, but they are polished, and that includes the water-pump cover.

For the top end, none of the stock parts returned. A 305cc PC 2000 cylinder and head kit replace the stock jug. With the addition of this Nikasil-plated-bore, power-valve cylinder, the displacement jumps to 305cc. This engine kit is tuned for mid-range since Mayer’s plans were for desert riding and not dune running.

The intake side of the top end starts with a stock airbox filled with a K&N air filter. It is attached to a new Keihin 39mm carburetor with Duncan Super Flow mods. It is clamped to a Duncan Pyramid reed cage intake. On the other side of the cylinder is a steel exhaust flange with double O-rings for better sealing. Inserted in the flange is a Paul Turner Eliminator pipe with a Fat Boy silencer at the end.

Duncan Racing likes the cooling properties of a radiator from a Honda CBR street bike. It is joined to a water pump with CV4 silicone radiator hoses. This is a finely tuned engine that makes a lot of power. Duncan builds it to eat VP C-12 race gas and Maxima lubricants and coolant.

Duncan Racing builds a quality performance machine, but it also pays close attention to the mix of colors and finishes to produce a striking result.

PUTTING IT ALL TOGETHER

When all the cleaning, replacing, refinishing and modifying were finished, Mayer had a beauty of a quad that weighs a svelte 350 pounds. Mayer praised the result: “The experience—from roller to trail riding—was really great because of Duncan Racing’s hard work. The process was fun and the results were beyond expectations. I look forward to doing another build with Loren and Leonard in the future.

“When you ride the quad, every input is amplified. This TRX305R pulls harder, turns sharper and brakes harder all while keeping its composure. Where I ride is rough, and this quad can handle it. My Banshee wasn’t the best. The linkage hangs pretty low, so the Banshee is for dunes now.”

We love it when somebody sinks heart, soul and wallet into a build, then rides it where there are rocks, brush and cacti. Way to go, Mayer.

PARTS AND SUPPLIERS:

BAJA DESIGNS: (800) 422-5292, www.bajadesigns.com

Light package: $995

BERINGER/FROG SPECIALTIES: (310) 817-5447, www.frogspecialties.com

Complete brake kit $3500

Clutch perch $200

DUNCAN RACING INTERNATIONAL: (619) 258-6306, www.duncanracing.com

Complete engine rebuild $695(+parts)

Duncan Racing PC 2000 305cc power-valve engine kit $2995

Triple-plate pipe chroming $199

DR C12 clutch kit $199.95

Yukon HD transmission gears $995

Custom heel guards $399

Crown Series steel-braided rear brake line $39.95

Crown Series steel-braided front brake line $119.95

Brake line holders $40 pair

CBR radiator $499

Chrome front bumper $229

Engine skid plate $200

Chromed subframe, upper A-arms, shifter, kick-starter, rear brake pedal Varies w/plating prices

Powdercoated frame, swingarm, lower A-arms Varies Team graphics kit $149.95

Dual O-ring steel exhaust flange $79.95

Titanium bolt kit (including swingarm pivot bolt) $995

Billet chain guard $39.95

Master cylinder guard $49.95

Machine cases for big bore cylinder $195

Crankshaft rebuild labor & rod kit $295

Polish side cases & water pump $245

Powdercoat center cases satin black $250

HESS MOTORSPORTS: www.hess-motorsports.com

Sprocket guard $79

Disc guard $150

FOURWERX CARBON: (262) 501-9696, www.fwcarbon.com

Seat kit $349

Tank cover $249

Hood $199

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

Basket w/cushions $284.95

IMS PRODUCTS: (800) 237-9906, www.imsproducts.com

4.0-gal. tank $279.00

MAIER MFG.: (800) 33-MAIER, www.maier-mfg.com

OEM style plastic $499

MAXXIS TIRE: www.maxxis.com

Razr2 tires 21” fronts/20” rear $500

OMF PERFORMANCE WHEELS: (951) 354-8272, www.omfperformance.com

Beadlock wheels $239 ea.

PRECISION RACING PRODUCTS: (209) 365-1850, www.precision-rp.com

Steering stabilizer $600

PRO DESIGN: (714) 534-0620, www.prodesignracing.com

Cut-off switch $39.95

RK CHAIN: (760) 732-3161, www.rkexcelamerica.com

O-Ring chain $99

ROLL DESIGN: (760) 731-5920, www.rolldesign.com

2018 LOBO complete chassis assembly $19,000

TRX 250R billet front hubs $495

Stainless foot pegs $239

RPM: (928) 771-9363, www.team-rpm.com

Dominator axle $459

Bearing carrier $218

Anti-fade nut $230

SUNSTAR SPROCKETS: (937) 704-1462, www.sunstar-braking.com

14T countershaft sprocket $26.95

Steel 38T rear sprocket $45

TAG METALS: www.tagmetalsracing.com/moto/us/

CR Hi handlebar: $129

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