A Harley-Davidson Sportster That Knows The Way To San Jose

This article was originally published in the 2003 issue of Power & Performance magazine.

The problem with most replicas is that, well, they're not really replicas. Case in point: Harley-Davidson's 883R. In describing the small-bore Sportster, The Motor Company claims, “With just a quick glance, you might think a grand national dirt-track hike is doing a victory lap.” Read between the lines, then, and what we have here is a Racing Orange homage to the venerable XR750 that has dominated dirt-track racing for more than three decades.

Trouble is, aside from a lookalike paint job and checkerboard gas-tank graphics, along with a wide, dirt-track-style handlebar and a centrally mounted speedometer designed to mimic a racing tachometer, the XL883R bears little actual resemblance to the iconic V-Twin racebike that has carried such racing luminaries as Jay Springsteen, Scott Parker, and Chris Carr, among others, to countless AMA Grand National titles.

That, folks, just isn't right.

So, we decided to build a genuine dirt-track replica using the $6795 883R as the jumping-off point. Our project bike would remain street-legal, but would be more authentic in its appearance, with uprated engine performance and better handling to boot.

Work began with the 883 engine. Not wanting to sacrifice reliability, we kept the modifications simple: Screamin' Eagle 1200cc cylinders, High-Flow Air Cleaner and Thunderslide kits, Buell Thunderstorm heads with matching high-compression pistons, and the pièce de résistance—a high-rise SuperTrapp 2-into-2 XR-style exhaust system.

With the lone exception of the SuperTrapp pipe, all of these performance parts may be either purchased from Buell or found in Harley-Davidson's comprehensive Parts & Accessories catalog. As a result, all of the pieces bolted together pretty much as they would with a standard engine. Equally important—especially for anyone with average mechanical skills—only basic engine knowledge is needed to put this package together.

Moving on to the chassis, we swapped the stock damper-rod fork for the more sophisticated and externally adjustable cartridge fork from the Sportster 1200 Sport. Despite their many differences, both forks have the same outer tube diameters and brake-caliper mounts, making the change exceptionally easy.

Out back, the stock shocks, which are stiffly sprung and lightly damped, were shelved in favor of a set of Works Performance Pro Racer units. These beautifully crafted, competition-ready shocks mate finned-piggyback reservoirs with machined-aluminum bodies, feature separate low- and high-speed damping circuits and are fully rebuildable. They're also a couple of inches longer than the stock dampers, not to mention having adjustments for ride height, both compression and rebound damping, and for spring preload.

Longer shocks required a longer muffler bracket. We simply duplicated the low-tech steel strap supplied by SuperTrapp—in the correct length, of course—drilled attachment holes, then spray-painted it black. Through some trial and error, we were able to bend the new bracket into a shape that provided the proper clearance for the right-side shock and stacked mufflers.

Next up, wheels and tires more befitting a dirt-tracker. With the XL883R, Harley stuck with the 19-inch front, 16-inch rear setup found on most late-model Sportsters. Racers, however, prefer the tried-and-true 19/18-inch combination, which also works well on the street. Unable to find an 18-inch rear to match the nine-spoke cast-aluminum front, we purchased a pair of Sun rims in the stock widths, had them anodized to match the blacked-out handlebar, frame and engine, then laced them to H-D hubs using stainless-steel spokes. With rim strips, endurobike innertubes, and DOT-approved, dirt-track-spec Dunlop K180 tires, the wheels have the right look and weigh a full 7 pounds less than stock.

Racing XR750s are not allowed front brakes on the ovals, just a large rear. But on the street, good brakes—both front and rear—are an absolute necessity. The 883R is equipped with the same dual four-piston-caliper, twin-disc front stoppers used on other late-model Harleys, including the V-Rod and Sportster 1200 Sport. They are decent brakes, but we thought the front of our repli-racer deserved a slightly firmer feel at the lever. Harley sells stainless-steel brake lines for the Sporty that are less prone to expansion than the stock rubber lines, but they come with flashy chrome fittings—not exactly what you'd find on a racebike. So, we instead went to Goodridge for a set of its custom Ebony Series lines outfitted with matching black-anodized banjo bolts and steel fittings. To further improve stopping performance, we used Bel-Ray DOT 4 brake fluid and the latest Ferodo brake pads—SinterGrip up front and Platinum in the rear.

Having finalized the engine and chassis, at least for the moment, we turned our attention to what was arguably the most important facet of our project: the bike's appearance. There are many who maintain that dirt-track is motorcycle racing at its purest, and the big, bellowing XR750 is the longest-running, most successful example of the breed. Unlike the constantly evolving machines used in other forms of two-wheel competition, dirt-trackers have remained pretty much constant over the years, the biggest change being the relatively recent shift to single-shock rear suspension. As such, XRs are somewhat simple devices, devoid of the fairings, fenders, electric starters, and other "novelties" commonly found on, say, roadracers.

Unfortunately, duplicating this decades-old elemental look is more difficult than it might seem, especially since our bike had to remain street-legal. Storz Performance sells an XR-style fiberglass tailsection and seat pad, as well as a mounting kit that includes a taillight and license-plate holder. Great, except that its installation calls for a large portion of both rear-fender support rails to be hacked off the frame. This essentially constitutes a permanent modification, one that we did not want to make to our testbike, which was on loan from The Motor Company. But had the bike been ours to alter, we would have dragged out the Sawzall and forged ahead with the Storz setup.

If that was the bad news, the better news was that Harley also sells a fiberglass tailsection, though it is delivered unpainted and with no consideration for fitting street equipment. But in its favor is the fact that the tailsection incorporates built-on covers for the aforementioned fender supports, which are intended to serve as mounting points for number plates. Seat foam and a snap-down vinyl cover are sold separately.

Our plan, then, was to combine the Harley tailsection with Storz's mounting kit. But we soon found that this scenario offered its problems too. As noted in the Harley catalog, the tailsection is intended for use with the old-style 2.3-gallon XL gas tank, not the 3.3-gallon tank fitted to current Sportsters, including the 883R. Sportsters are generally pretty thrifty on fuel, but an 80-mile range is ridiculous! So, we retained the stock gas tank and reworked the front of the tailsection on a belt sander, which eventually enabled a perfect fit around the rear of the tank.

Next on our list of Things To Do was to paint the tailsection. California Cycle and Watercraft matched the orange base coat found on the front fender and gas tank, then added black backgrounds and white pinstripes to the sides of the tail to echo the gas-tank graphics.

Now for a seat. Saddlemen sponsors long-time dirt-track front-runner Kevin Atherton, among others, in the AMA Grand National series, so it knows a thing or two about building seats for XR750s. We requested a duplicate of the seat used on Atherton's racebike, customized for the modifications made to the front of the tailsection. To up the comfort quotient, we also asked for the company's proven Saddlegel insert.

Lighting was last. To keep costs down, Storz's kit makes use of the stock turn signals, but we wanted something less bulky than the standard chrome bullets. Lockhart-Phillips USA isn't part of the vast Harley aftermarket, but it does sell a wide array of blinkers in all shapes and sizes. We opted for a set of Short Stalk Vs, which feature small, aerodynamic-looking housings and are available with clear, amber, smoke, or iridium lenses.

Making everything function in conjunction with the stock wiring harness was a task in and of itself. Focusing first on the back of the bike, we removed the wiring junction box from the interior of the stock taillight and grafted it onto the back of the Storz taillight assembly. We then clipped off the male leads from the original taillight and turn signals and wired them to their Storz and Lockhart counterparts. With everything in place, the result is tidy, and it can be easily and quickly disassembled should the tailsection need to be removed.

Up front, we fabricated a pair of simplistic aluminum brackets to which we attached another set of Short Stalk Vs. The brackets were then mounted behind the pinch bolts on the lower triple-clamp. Getting all four of the turn signals to interface properly with the Harley turn signal module required a Badlands load equalizer, which we connected to the main wiring harness and siliconed to the top of the XLs oil tank.

We initially envisioned this project as something that could be easily and painlessly completed in a weekend's time. Unfortunately, that was hardly the case, as many parts were backordered or had to be modified. But it does help explain why we were so fired up when the day finally came to actually, uh, fire up our 883R.

And what a sweet-running machine it turned out to be. These days, a competitive XR750 churns out about 100 to 110 hp and somewhere around 70 pound-feet of torque. At 59 hp and 66 lb.-ft. of torque, our uprated engine certainly doesn't meet those standards, but it is significantly more powerful than the 883 stocker, which only made 43 hp and 45 lb.-ft. of torque. What's more, the SuperTrapp pipes endowed the bike with a gutsy exhaust note that would be right at home on any starting grid. It isn't overly loud, either, and it looks terrific, with the stainless-steel tubing gradually turning a beautiful straw-colored hue.

Dirt-track bikes aren't about comfort. They're purpose-built, no-frills competition machines specifically designed to get around a dirt oval in the quickest time possible. Except when they're in full-tuck on the straightaways, dirt-track racers sit fairly upright with their weight positioned as far forward as possible to help the bike turn. Knowing this, we never expected our project bike to have the plush ride of an Electra Glide, even with comfort-enhancing Saddlegel in the seat. But to achieve the correct look and fit the race-spec tailsection, the Saddlemen seat had to be thin and narrow, stipulations guaranteed to impose on comfort—at least during longer jaunts. Hey, maybe that smaller gas tank wasn't such a bad idea after all!

Still, the stock, dirt-track-esque ergonomics make for a bike that is easy to ride on a twisty road. The wide handlebar provides excellent leverage, while the taller shocks provide additional cornering clearance and more responsive handling, along with greatly improved chassis control. As for the dirt-track-spec Dunlops, they offer neutral steering and surprising grip. And compared to top-of-the-line radials, they are an absolute bargain.

Our project bike's 40-plus-pound weight loss—8 pounds of it from the cylinder swap alone—didn't hurt the bike's handling, either. Without fuel, our "1200R" scaled in at very respectable 475 pounds. That's not XR750 territory, but it's a whole lot lighter than anything in Harley's current lineup.

Despite extremely positive overall results, this was a rather expensive bike to build. For the money spent, the larger-displacement engine is a no-brainer. It's also easy to justify the cartridge fork. The bucks-up Pro Racer shocks, with their many adjustments, however, are overkill for most street riders, but they sure look trick. Works Performance also sells Street Trackers, which offer threaded spring-preload adjustment and cost less than half the price of the Pro Racers.

Which brings up an important point: In attempting to duplicate this project, everything need not be done all at once. Like the look of the pipes and tailsection? Go for it. Can't quite justify the cost of new wheels and tires? Make do with the stock stuff and weigh your options at a later date. There are no hard-and-fast rules here.

Of course, it would be a lot easier if Harley-Davidson would just build a real XR750 replica. If Willie G. and crew had any intention of doing so, though, they most likely would have done it by now. Bottom line, then? If you want to capture the look and feel of an XR750 in a Sportster-based streetbike, you'll simply have to do as we did: Build it yourself.