Street-Legal Dirt Tracker from Vintage Sykles…
Austrian-born engineer, Grand Prix motocross racer, and ISDT gold medalist Horst Leitner founded ATK in 1985 after relocating to the United States. The name derived from Leitner’s patented “A-Trak” — a device designed to reduce chain torque. ATK machines quickly became regular winners in the Four-Stroke Nationals, and by the 90s, ATK was one of the largest off-road motorcycle manufacturers in North America, operating out of their headquarters in Utah.
In the mid 1990s, the ATK 605 appeared, which was basically an ATK “Cross Country” dirt bike with lights. At the time, no other dual-sport machine was this aggressively dirt-oriented. Cycle World compared the big ATK to their “Best Dual Sport Motorcycle,” the Honda XR650L:
“The ATK 605 makes the Honda feel like a streetbike. If the XR-L is a 75/25 dirt-to-street mix, the ATK is biased 95/5.” –Cycle World
The ATK weighed 30 pounds less than the Honda with a full 4.3-gallon tank of gas, and the 598cc single-cylinder Rotax was one of the most proven engines in the two-wheeled world.
The WP forks were the same high-spec units that came on KTM models of the time, featuring a large degree of adjustability, and the seat height of 38+ inches only confirmed the 605’s single-minded focus. The ATK didn’t even have a speedometer, ignition key, or fork lock.
“If you’re after a dual-purpose machine that strictly adheres to the dirtbike-with-lights dictum, then the ATK 605 is about dead-nuts perfect. This bike can be raced competitively in off-road races; it will do a good job of carving up twisty pavement through a canyon; and it will take you to the comer store for a quart of milk-if you carry a lock and chain.” –Cycle World
Enter our friend Pete Sykes of Vintage Sykles, who raced flat track in Pennsylvania’s District 6 back in the 1970s. A tragic accident took him away from the sport for many years, but he found his way back to two wheels in earnest, building bikes and custom aluminum parts as a side business.
“When I retire from my day job I hope to create motorcycles and aluminum seat pans, fenders, and fuel tanks. I am blessed!”
Three years ago, we featured Pete’s Kawasaki Zephyr 550 street tracker — aka “Problem Child.” Now he’s back with with the 1999 ATK 605 you see here.
“The bike was given to me by a very good customer and friend who gave me free rein to make it into a one-of-a-kind tracker.”
The fuel tank is a one-off unit built out of aluminum to fit the slanted backbone of the frame. The race-inspired look of the lightweight tank then spread to the rest of the build.
Pete fabbed up the front number plate with MX Numbers graphics, micro LED signals, and a small but powerful Baja Designs headlight for the look of a street-legal DTX bike — a motocross bike converted for flat track racing with lowered suspension and 19-inch wheels.
“Throw your leg over this ATK605 and get ready to hold on tight. This bike can compete at your local flat track race or you can run it as a bar hopper on Saturday night.” -Pete
An Öhlins rear shock helps get the torque of the big single-cylinder Rotax to the ground, while Shinko flat track tires provide grip on both dirt and tarmac. Pete modified the subframe to fit the tail section and number boards (courtesy of New Zealand’s C•Racer), and the bike got a full rewire. Brembo brakes haul the bike down from speed, and the engine got a full service, too.
We love the track-focused direction of this ATK street tracker, and it’s nice to see such an uncommon donor, too. Even better is Pete’s attitude about the process — one of the best mindsets in the business:
“Overall the bike turned out to be a creation of my imagination which ran a little wild. I’m very grateful for the opportunity to build bikes and don’t take it for granted. Every challenge that comes my way is a blessing even though sometimes they are very hard, but the pleasure you get in the end result is well worth it.”
Below, we talk to Pete for more details on this ATK street tracker he calls the “Canyon Runner.”
ATK Street Tracker: Builder Interview
• Please tell us a bit about yourself and your history with motorcycles.
I’m a old flattrack racer from the 70s and raced Pennsylvania’s district six. I like to call myself a motorcycle enthusiast and truly appreciate all motorcycles and anything with two wheels .
I’m 64 years old and live and work in Worcester, PA, which is right outside Philadelphia, PA ( go birds 🦅) . When I retire from my day job I hope to create motorcycles and aluminum seat pans , fenders and fuel tanks. I am blessed!
• Please tell us about the build.
Throw your leg over this ATK605 and get ready to hold on tight. This bike can compete at your local flat track race or you can run it as a bar hopper on Saturday night.
The bike was given to me by a very good customer and friend who gave me free rein to make it into a one-of-a-kind tracker.
I started by stripping the bike down and soon realized the backbone of this bike was slanted making it impossible to fit a normal tank on. I then decided to fabricate an aluminum fuel tank that would be a one-of-a-kind.
I wanted to make something unique that would fit the style I had in my imagination. The end result was a very weird but somewhat handsome fuel tank, which looked very racy.
Once I had the tank done I ordered a beautiful seat and side number plates from C•Racer in New Zealand. I then built a rear seat mount that I welded to the stock subframe.
This modified subframe allowed me to mount the seat, taillight, and side plates.
I fabricated the front number plate and used vinyl graphics for the numbers from MX Numbers out of Idaho. I also mounted small LED turn signals to the front number plate.
The wiring was in very bad shape, so I dove in and fixed all the problems, which ended up being just about a whole new wiring harness. I soldered all the connections together; this allowed the bike to prowl the streets legally.
The bike is outfitted with Brembo brakes, an Öhlins rear shock, and a front end made by White Brothers.
I used a Koso electronic speedometer, which mounted to the handlebars along with a Baja Designs front headlight.
Some of the other features of the bike include Shinko flat track tires, UFO front fender, Bates foot peg rubbers. Engine serviced with a carb cleaning and oil and filter change as well as new brake pads and fluid.
Overall the bike turned out to be a creation of my imagination which ran a little wild. I’m very grateful for the opportunity to build bikes and don’t take it for granted. Every challenge that comes my way is a blessing even though sometimes they are very hard, but the pleasure you get in the end result is well worth it.
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