Twenty years ago, street-legal supermotos weren’t really ‘a thing.’ But in Europe, change was in the air—and the KTM Duke II was one of the catalysts. The rough-and-ready 625 cc single was huge fun on short trips, and helped set the template for future supermotos.
Over the past couple of years, custom supermotos have become more common, delivered by builders who value performance as much as aesthetics. And one of those builders is Garett Wilson of Dubstyle Designs in Colorado, USA.
“These Dukes have a cult following, but not many people really know them,” he says. “Google the things—they were nothing short of ugly!”
This Duke is Garett’s daily rider now, but he had a vision for a KTM street tracker years before he began this build. It gave him time to research and collect parts, so when the spanners started spinning, he had most of what he needed.
He started by ditching all the plastic and planning new bodywork. For inspiration, he turned to the past and the days when the bodywork of Austrian off-roaders was relatively conventional.
“I based the design on a 1979 KTM,” he reveals. “I’m also a fan of vans with side pipes, boat flake paint jobs, and girls with feathered bangs. So of course, I had to go with an old school, retro paint scheme.”
On a more serious note, Garett has two main goals with each bike build: make it lighter, and increase performance.
“My plan with every bike is to make it perform better,” he says. “The stock Duke II weighs 320 pounds dry—and even with a full tank of gas I was able to get this one down to 305 [138 kg].”
To level out the stance and proportions, Garett has swapped out the stock 17-inch mag wheels for 19-inch Sun rims. They’ve got Buchanan spokes laced to KTM hubs, and spacers machined to fit.
Durelle Racing lowered the high-spec WP suspension about two inches front and rear, and Garett machined up a set of fork guards on his lathe. He’s also painted the monoshock spring to match the rest of the bike.
A new subframe was fabbed up to follow the lines of the fiberglass tail section. “I also added material to the back of the tail section, making room to flush in the turn signals and LED tail lamp.”
Garett sourced the tank from a salvage yard, taking it off a 1978 Honda Hawk. He then had to narrow the front of the tank, so that the forks would still work lock-to-lock. “I also added clearance underneath the tank, to have room to mount some electronics.”
The headlight is set into a carbon fiber number plate; Garett added a couple of extended mounts to set the plate away from the forks, creating room for the lamp to be recessed behind the plate.
The Duke II is not short of performance, thanks to a strong power-to-weight ratio. But Garett’s boosted it a little further by improving the breathing.
“On the four-stroke bikes I build, I like using exhaust cans designed for the Yamaha R6,” he says. “So I paired an FMF Apex muffler with a Megabomb header, and fitted them together with stainless steel. Combine that with the Keihin 41mm FCR carb, and further into the RPM range the Duke pulls a lot harder.”
Cooling down the motor proved to be trickier. “I took a tape measure to the salvage yard and measured a lot of different radiators, to find one that would fit between my forks and the new tank,” says Garett.
“It took a while to find one that would give me enough capacity without being an eyesore.” He finally settled on an aftermarket aluminum radiator from an old Honda Magna.
Dan White handled the paint. “He kills it on my paint jobs every time—he’s super meticulous, and will do whatever it takes to make the paint perfect. All the graphics on this KTM are painted on,” Garett reveals. “But after taping off the tank I should have unmasked it sooner.”
“By the time I took the tape off, the humidity had created some surface rust on the inside of the tank. So the night before I had to have the bike running, I had it soaking in some as-seen-on-TV rust remover!”
“The next morning I was butt naked in the shower with my freshly painted gas tank while I flushed it out. It’s environmentally safe, nobody freak out—but that’s one story I never did tell my painter!”
We reckon the Duke is close to perfection, and Garett is reasonably satisfied. “With each build I’m trying to class it up a bit to make a more ‘finished’ product. I build my bikes out of the home garage so there are always challenges.”
“#1 on that list is my 5-year-old Cam, who is obsessed with tools—and he helps by snagging all of the 10 and 13mm sockets he can get hold of!”
“My favorite thing about the Duke is that it’s always ready to go,” Garett says. “I ride it to work every day that Colorado lets me. It’s got the right stance, it sounds mean as hell, and just rides nice—which to me is the whole point of having a motorcycle.”
“If I build something that looks crazy but is unrideable, then what’s the point?”
Dubstyle Designs Instagram | Images by (and with thanks to) Sam Bendall
