Sweet Tracker | Stock Sportster to Dirt Track Racer
A few issues back I dedicated my monthly column to converting a stock Sportster into a street tracker, a dirt track racing replica (picture Harley’s XR-750), but able to be legally ridden on the street. The Harpoon drew up a rendering of what the bike was to be, with the only instructions being that I wanted a black and gold theme. He nailed it. I got to thinking though… A street tracker limits you to only being able to ride on the street. I wanted the option to ride around the oval at Costa Mesa Speedway in Orange County, California, with proper dirt track tires as well. I’ve become a huge fan of flat-track racing, and it has been a goal of mine to race flat track. Why not have both? I struck a deal on a 2000 XL883 Hugger Sportster at Skip-Fordyce Harley-Davidson in Riverside, California and once I got the bike home I stripped all the crap off that would inhibit its ability to haul ass and look cool.
To start the project, I needed a proper roller, fit for the dirt track style. In order to do so, I’d need dual 19-inch wheels to fit the iconic 19-inch Dunlop CD5 dirt track tires ($165 ea). These tires have been rolling racers around tracks for years so it was only natural to use them for this project. They are not DOT approved however, and are only meant to be ridden on the dirt. The rubber compound simply won’t hold up on ashphalt, according to Dunlop. They’re only available in 19-inch diameters with varying widths so do some research on fitment specs. When I’m ready to ride the bike on the street I’ll have to get some street tires.
To save a buck on wheels, I converted a front 13-spoke, 19×2.15-inch cast wheel into a rear that I found on Craigslist for $50 using a couple of machined spacer blocks attached to the outsides of the hub in order to mimic the stock wheel width (one in between the wheel and sprocket, one in between the wheel and brake rotor). I knew that Wheel Works in Garden Grove, California, was up to the challenge since they’re the local gurus in Orange County.
I also wanted to convert the final drive from being belt driven to chain driven since no respectable dirt track racer runs a belt. Baker Drivetrain has the goods when it comes to trans and wheel sprockets, chains, etc. And since this was a special application, I selected parts on more of an a la carte basis. The company does offer all-in-one belt-to-chain kits though so just give them a call and they’ll hook you up. In this case, since the converted 19-inch rear wheel is 3 inches taller than stock, the trans/wheel sprocket ratio had to go from the standard 27/61 teeth configuration to 23/52 in order to mimic the stock gearing. I ordered up a 52-teeth wheel sprocket (raw $135), a 23-teeth trans sprocket ($65), and a chain ($90).
With the frontend removed, I wanted to send the lower fork legs to Wargasser Speed Shop in Simi Valley, California to have the fender mounts shaved since I won’t be running a front fender (the service is $100 if you ship your set, for a new set it’s $150.). Wargasser does some really trick stuff for hot rods and motorcycles and they’re good guys.
To go with the legs, I ordered a set of Fork Gaiters ($39.95) from Lowbrow Customs. The Gaiters fit 39mm fork tubes and come in black, and 35mm and 41mm Gaiters are also available. With a subtle amount of sheen from the satin lowers and the dirt-inspired fork Gaiters, the Sweet Tracker should be right where I want it once everything’s complete.
With the front and rear wheels coming off, it was the right time to upgrade the front and rear suspension. Race Tech’s FLEK S3590 Fork Suspension Kit ($259.99) with Gold Valve Emulator technology emulates a cartridge style suspension setup. First of all, Race Tech drills more holes in the stock damping rod to flow more fork oil, which ultimately aids in better, more controlled oil flow and damping. The holes on the gold valves are also larger than stock to flow more oil in more of an unobstructed manner. The tunable gold valves sit atop the modified-stock damping rods inside the fork tubes and are held in place with the main springs. Once the fork oil passes through the modified damping rod, it reaches the Emulator’s bypass valve in the check plate, which provides a firmer, more controlled feel for the rider when encountering bumps. Since the gold valves are adjustable, riders can make adjustments by adding different springs to the gold valves to better fit rider preference and riding conditions. Race Tech offers multiple front and rear suspension kits for all Harley models.
Since I grew up around dirt bikes, I’ve always had a place in my heart for Öhlins shocks, and its unmistakable gold piggyback reservoirs. Öhlins is based in Sweden with many distributors around the world manufacturing shocks for multiple powersports industries. The company is making a push to offer more products for the American V-twin market and offers shocks for all the twin-shock Harleys (excluding Softails). With that said, the HD 141 S36PL shocks ($909) were the perfect fit for the style I’m after. S=Single tube, 36=Piston diameter, P=Gas-type with piggyback reservoir, and L=Adjustable length. Not only is the preload adjustable, but also the shock height can be adjusted to boot. The S36PL shocks are lightweight, brilliantly machined from aluminum, and are very easy on the eyes.
That about wraps it up for this installment of the Sweet Tracker. I have to thank the Wheel Works crew (Dave, Gary, Mat, and Adam) for helping me get the project multiple steps closer to getting it done. Stay up to date with the build process via hotbikeweb.com, facebook.com/hotbike, and twitter.com/hotbikemagazine. Also, there will be more in-depth build articles of the Sweet Tracker in future HOT BIKE issues and you don’t want to miss out, because as Ricky Bobby says, “If you’re not first, you’re last!” HB
Source:
Baker Drivetrain
(877) 640-2004 | bakerdrivetrain.com
Dunlop Tires
(800) 321-2136 | dunloptires.com
HB Performance Coatings
hbperformancecoatings.com
Lowbrow Customs
(440) 479-8129 | lowbrowcustoms.com
Öhlins USA
(828) 692-4525 | ohlinsusa.com
Race Tech
(951) 279-6655 | racetech.com
Wargasser
(805) 527-9899 | wargasser.com
Wheel Works
(714) 530-6681 | wheel-works.com