EDITOR’S NOTE: It’s evident that the Biltwell boy have a serious addiction. To Sportsters. More importantly, converting Sportsters into desert sleds capable of running competitively in Baja. When the crew built a desert racer the likes of a full-on Dakar Rally ripper for the NORRA 1000 in Baja back in 2018, it was defi nitely a challenging feat to say the least. That bike, dubbed Frijole, was a great way to open people’s eyes to how much potential the quad-cam Harleys can be for customizing. Especially in the dirt. When a spare parts Sportster was purchased for that race, it turned out none of the actual spare parts were needed, so the Biltwell crew decided to build another fun sled, but something more versatile for the street and the dirt. The Spare Parts Sportster before you is the brainchild of Bill and Rouser from the get. It’s fun to see the creativity behind these very capable off-road Harleys.

After we built the original Frijole 883 to race the 2018 NORRA 1000 in Baja California, Mexico, we picked up a cream puff 2003 883 as a “spare parts” bike. We stripped it down and brought the frame and engine with us in the chase van during the race in case we needed to scrounge parts or completely swap out the frame or power plant.

As it worked out, the race bike was way more durable than we expected and most of the spare parts came back in the van unused. The next year, Rouser built the “Spare Parts Sportster” out of this donor and the leftover race parts. Our buddy Ricky flogged this version of the humble Sporto at Lapaglia’s practice track and then our crew raced it at the Mint 400 and the fi rst two Biltwell 100 desert races.

Fast forward to 2023 and the bike was a little hammered and was time for a refresh. Our VP of Sales, Davin Wirtanen is a bad infl uence around here and his love for ADV bikes has been contagious. Harley introducing and loaning us a few Pan America motorcycles just poured fuel on the gravel road fl ame. I was considering a venerable KLR or Yamaha T700 as a pragmatic solution to this gap in my motorcycle quiver. Of course, either would have been fantastic and realistic choices, but then I recalled the ridden hard and put away wet SPS bike. In the spring of this year, Rouser traveled from his surf lair in remote Panama to come up for his annual work trip in Temecula, CA. We brainstormed about what it would take to convert this semi-retired race/thrash bike to become a more universal allrounder.

First, we defi ned the mission: A street-legal bike that is capable of 300–500-mile days while having some modern features, extra fuel capacity, and the ability to haul plenty of gear. Of course, it had to be off -road capable and not lose any of the race-proven provenance inherited from the original Frijole and also be comfy and competent on the highway. We went round and round about how to solve the extra fuel capacity issue. We didn’t want a strangely huge plastic tank, it just wouldn’t look or feel like a Harley. The simplest solution? Pop a couple Rotopax on either side of the H-D Pan Am top box. This way we fi t an extra two gallons in addition to the stock 3.3. This lends itself to roughly 200 miles without an external gas stop. I need a snack about every 100 miles or so anyway. Rob built a rear rack to support the Harley Pan Am top box (by SW-Motech) and the saddlebag supports, and I did a little TIG-welding to stick it all together. We slipped the yoke of our EXFIL-18 saddlebags over that rear support and rebuilt the exhaust system to keep its tucked-in compact routing but exit at a bag-friendly angle. (I was nervous that it was still too close to the bag, but a recent all-day trip proved that our work was not in vain, and the bag stayed intact instead of melting.)

How’s it ride? Rob’s rebuild with the S&S 1,200cc Hooligan kit makes this bike way more peppy than the original Frijole. Tim Statt at Giga Cycle Garage carved up some new trees with a slightly more relaxed head angle and we moved the steering stops to get a better turning radius than the old race bike. The gearing is perfect for mixed use. It’ll run 70 mph all day on the highway without feeling taxed but still has plenty of grunt down low to get this 500-pound wannabe dirt bike out of tricky situations off road. Rob’s attention to detail on the build confused fellow riders on a recent ferry ride in the PNW. Most of them insisted that it must be a new motorcycle and had a hard time believing it’s a 20-year-old Sporty.

The ergonomics are natural when seated and the standing position is totally comfortable for extended periods of time. Shifting is still GP-style to keep the shifter tucked and we kept the Rekluse clutch because it is such a fatigue-saver off -road. Rouser added heated grip liners which sounds pretty bougie for chopper types, but when it’s chilly, they sure are nice! Another modern touch is the Garmin Zumo XT2 navigator which also serves as a speedometer. Below that on the dash are aircraft style circuit breakers and switches for ignition, heated grips and the brilliant Baja Designs lights and a USB charger/voltmeter is built into the side of the Manic Rally Tower. Those Baja Designs lights BTW, are killer. I run the yellows in the daytime just to be seen.

Other race-proven bits are the Honda XR-400 oil cooler mounted on the neck and the Anti-Gravity battery with rigid mount. Like the race bike, we rebuilt the stock oil tank to bolt on to the frame rather than hang from the failure-prone stock rubber mounts. We ditched the push-in oil tank cap and welded in a threaded bung and custom aluminum cap. These oil tank mods are often overlooked by novice desert racers hopping up a Sporty—all it takes is one tip-over for the stock oil cap to pop off and all is lost in the middle of nowhere. Less racy, but visually important is the 2022 Subaru “Adventure Green” and flat black paint laid down by Pete “Hot Dog” Finlan.

This motorcycle may have been born and raised in the deserts of So Cal and Baja but it’s getting a new lease on life up on the Olympic Peninsula of Washington State. I moved up here to the upper left in Port Angeles this summer and the ADVXL is the bike that gets the most use so far since it behaves so well in all environments. I’ve yet to take it on any multi-day epic adventures but that is absolutely the plan! HB

WORDS & PHOTOS: BILL BRYANT