Duke of Hazard: KTM 640 Duke II Street Tracker

KTM 640 Duke Street Tracker

In 1994, KTM launched the original Duke, a 610cc street-legal supermotard that helped transform the Austrian firm from a manufacturer of niche off-road bikes into a household name.  In ’99, they followed up with the 640 Duke II, possibly the most perfect/wicked hooligan platform ever created.  Said Cycle World of the 55-hp supermoto:

“Talk to any sport rider who’s crossed paths with one of these ‘Dukes of Hazard,’ and you’ll likely hear tales of wild wheelies, eye-popping stoppies, and an uncanny ability to gun down bikes twice its size in the twisties.”

KTM Duke Street Tracker

The only drawback of the Duke II — besides its penchant for earning “Speed Ex” citations — was the aesthetics. The “outrageous nosecone,” swoopy bodywork, and blaze orange livery weren’t for everyone…and the 17-inch wheels looked tiny beneath the long-travel WP suspension.

Stock Trim: KTM 640 Duke II

Enter Garett Wilson (@dubstyledesigns) of Colorado — a motocrosser who built an ’87 CBR1000 streetfighter right out of high school and spent most of his twenties racing motocross and starting a family. After that hiatus, he got back into building with a pair of street trackers built on one of our favorite platforms, the Yamaha SR500. He originally bought this 2000 KTM 640 Duke for his dad, but after building his old man his own SR, the Duke wasn’t getting much love:

“So I took the Duke back and began riding it to work. I couldn’t handle how it looked though and knew something needed to be done to make the looks match its performance.”

KTM 640 Duke Street Tracker

The kick-in-the-pants for the build came when Garett was selected as one of 13 builders for the Greasy Dozen Collective — an event hosted by the good folks at Old Bike Barn, where sponsors help garage builders kick-start their projects. Suddenly, Garett had just five months to finish the build. Garett decided to transform the factory supermotard into something of a street tracker, with twin 19-inch wheels and more of a retro style, basing the livery on a ’79 KTM. However, aesthetics weren’t his only concern:

“My goal with every bike is to make it lighter and perform better – the internet says dry weight for a Duke is 320; I’ve gotten this one down to 305 with a full tank of fuel.”

KTM 640 Duke Street Tracker

The last couple weeks had enough “Biker Build-off” drama to rival a season of American Chopper, but that’s part of the fun. After many late nights and energy drinks,  Garett and a couple buddies made the 17-hour drive straight through to Columbus, Ohio, for the Greasy Dozen show:

“It was a totally awesome experience out there that I can’t thank the Old Bike Barn dudes – Bear and Zane – enough for putting the event on and selecting an ugly KTM to watch be transformed.”

KTM 640 Duke Street Tracker

Below, we get more details on this KTM street tracker, along with some great shots from Phil Lambert of Vital Imagery and Garett himself.

640 Duke Street Tracker: Builder Interview

KTM 640 Duke Street Tracker

Please tell us a bit about yourself, your history with motorcycles, and your workshop.

I’m Garett Wilson – a motocrosser at heart but I love all types of motorcycles. Growing up, I started riding on the PW50 and raced on a KX80 until team sports took up all the time. I started racing again after college on a KTM450 – I have a pretty sweet collection of plastic trophies to show for it. Typical life story here – have a couple kids + tore an ACL = no more moto.

The first bike I built was right after high school – it was an ’87 CBR1000 – German Streetfighter Style. I put a VFR swingarm on it, RC51 forks, and a 1000rr tail section. Looking back at that one it seems pretty sketchy and there are a thousand things I’d do differently. I use each bike as a learning lesson though – that one taught me to be much more detail-oriented and to have a more complete vision put together before beginning a build.

About 10 years went by before I built another bike as I spent my 20s racing moto and starting a family. I got back into it though by building a bass boat gold Yamaha SR500 street tracker, then another SR500 for my dad, then this KTM Duke. Waiting their turn in the garage are an RD400, RD350, XS650, a DT80 (for the “kids”), a DT360 and H1 triple Kawi. Between my buddy and I, we’re slowly acquiring the tools and fab equipment needed to help us progress each bike we build a little further.

KTM 640 Duke Street Tracker

What’s the make, model, and year of the bike?

2000 KTM Duke II.

Why was this bike built?

I originally bought this Duke so my dad would have something to ride alongside my mom on her newly acquired Sportster. It was borderline ugly with hideous “supermoto” bodywork, but it was a blast to ride and the price was right. Fast forward four years and my dad was now splitting ride time between the SR500 I built him (which turns out is way faster than my SR due to it’s high comp piston and Johnsons roller cam/rockers) and his own Harley, so I took the Duke back and began riding it to work. I couldn’t handle how it looked though (what’s that saying about scooters and fat chicks?) and knew something needed to be done to make the looks match its performance. I had a decision to make – either dump a bunch of money into my SR500 engine so it would be faster than dad’s, or use that money to turn the Duke into something that was both fun to ride and good to look at.

KTM 640 Duke Street Tracker

Last winter, before I looked up how far it was from Colorado to Ohio, I entered the Duke to be part of the Greasy Dozen Collective. The Old Bike Barn puts this awesome event together – they get some sponsors set up to donate to 13 lucky builders to help kick-start bike builds (entries are now being accepted for this year – check @thegreasydozen on Instagram). I was selected to be a part and had five months to build the Duke into something worth looking at. The last couple weeks leading up to the meet was full on “Biker Build-off” drama – normal work life during the day and then staying up until 2 or 3 in the morning to get it ready to go. The day we left I was up at 4am (queue the dramatic music) and was able to get everything buttoned up before going to work. I had only changed the exhaust and intake so the engine hadn’t been opened up, but I was still nervous as I loaded it into the trailer without any sort of test and tune. Luckily for me, I have a couple like-minded buddies in town – one of which was also selected for the Collective, and the three of us tag-teamed the 17-hour drive straight through to Columbus. I had to make a few mods to it once we got to Ohio but it made the whole ride to the camp and managed to not get pushed into the burnout pit during the festivities. It was a totally awesome experience out there that I can’t thank the Old Bike Barn dudes – Bear and Zane – enough for putting the event on and selecting an ugly KTM to watch be transformed.

KTM 640 Duke Street Tracker

What was the design concept and what influenced the build?

I’ve always liked the idea of a supermoto bike with suspension to bomb off curbs and speed bumps or rally the occasional ditch, but always thought the 17” wheels looked small. The overall proportions of the flat track bike and its 19” rims have always looked better to me. What I put together was a mixture of the two platforms.

The paint scheme for this was inspired by my take on a 1979 KTM. Most of my bikes tend to be a little retro-themed because I’m a fan of the 70’s and 80’s paint schemes. I don’t recommend laying stripes out on a tank when your build deadline has left you sleep deprived and buzzing on energy drinks, but they turned out straight. I can’t thank my friend Dan White enough for dealing with my crazy deadline and still killing the paint.

KTM 640 Duke Street Tracker

What custom work was done to the bike?

The tank came from a CB400 Hawk. It needed some massaging to give it a little more clearance at the front so that forks could clear lock to lock, but it mounted up easy enough and gave me room to hide the CDI and other electricals between it and the frame. I searched for a while for a good-sized radiator that wouldn’t be such an eyesore yet still have enough cooling capacity. This is an aftermarket aluminum one made for a VF750 Sabre.

KTM 640 Duke Street Tracker

The tail section is fiberglass from Goon Glass – I shortened it a little, added an extra bodyline, and made a spot to stick the LED tail lamp. The headlamp is also a LED that shines out through the hole in the number plate. The subframe was built to follow the lines of the tail section. I brought my seat pan/foam to my homie Brian and he did the rest – matching the stitching to the cool KTM patches and as always doing it in no time at all.

KTM 640 Duke Street Tracker

The KTM already came with Brembos front and rear but I did have to make a carrier for the front rotor to space it out yet clear the inside of the fork leg and also found a rear master with a built-in reservoir. For some reason the stock clutch cable is prone to snapping on the LC4 setup, so I fit up a Magura Hydraulic clutch – the feel it gives is fantastic.

KTM 640 Duke Street Tracker

I installed a Keihin FCR41 and Uni filter and cut the original exhaust up to create the downpipe to the carbon FMF apex that was made for a R6.

KTM 640 Duke Street Tracker

I found the Sun rims on eBay and with Buchanan spokes was able to fit everything to first generation Duke hubs. I brought the suspension to Durelle Racing to make sure it would have the correct stance but still function. It was lowered about 2 inches front and rear and of course the spring had to be painted orange to match. My goal with every bike is to make it lighter and perform better – the internet says dry weight for a Duke is 320; I’ve gotten this one down to 305 with a full tank of fuel.

KTM 640 Duke Street Tracker

Does the bike have a nickname?

Ummm does El Duque count? It was already called the Duke so I figure that’s good enough.

KTM 640 Duke Street Tracker

How would you classify this bike?

Street tracker.

KTM 640 Duke Street Tracker

Was there anything done during this build that you are particularly proud of?

With every bike I do I’m able to learn from mistakes and learn different ways to get to the end product. Each build gets more refined and “finished” – and at some point I may even sell one after I build it (that’s what I tell my wife anyway – shhh!).

KTM 640 Duke Street Tracker

Follow the Builder / Photographer



  1. beautiful work … !

  2. Peter Brück

    Very good Work.Im looking since a long Time for Inspirations for my 2001 KTM 640 EGS.This is exactly the Thing,with perfekt Proportions,and a Tank that really fits on it.
    Is the Frontfork original from a Duke,or do you shorten it.
    With a fourstrokefull hello from Germany.
    Peter Brück

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