Kawasaki ZX-6R Streetfighter by Wrench Kings

Kawasaki ZX-6R Streetfighter Tracker

The Wrench Kings of Holland have quickly become one of our favorite builders. Their uber-sexy CB750F cafe racer was a huge hit with our readers, making its way onto our list of the Best Cafe Racers of 2016, and the ‘Kings never fail to bring us delicious photographs of their builds — usually taken by the inimitable Bas Duijs. For all these reasons, we’re thrilled whenever one of their builds turns up in our inbox.

What we have here, however, is a welcome departure from their normal vintage build. In the ‘King’s words:

“An ugly, outdated 600cc Kawasaki ZX-6R Ninja…”

But one of the greatest joys of custom-building is transforming an unloved hunk of machinery into something bad and mad. Such is the case with this genre-busting Ninja 600, which looks like something between a streetfighter, tracker, and supermoto. Call it what you will, it looks like a hell of a hooligan machine, with pictures fittingly taken on an old airfield before the cops arrived.

Kawasaki ZX6R Street Tracker

Below, the Wrench Kings give us the full story on the build.

Kawasaki ZX-6R Tracker/Fighter:  In the ‘Kings’ Words

Ninja ZX-6R Streetfighter

(Words by The Wrench Kings. Highlights by us.)

Some time ago a friend of the Kings came across this bike and decided to buy it. An ugly, outdated 600cc Kawasaki ZX-6R Ninja… He drove it for a couple of months and had some fun with it. Then his sister decided to get married to a Portuguese guy named Henrique. With the wedding coming up, our friend decided to make this bike a wedding gift for his brother in law (Henrique)… Of course along with a business card of Wrench Kings!


Henrique had the best wedding ever: He got married to his beautiful wife (Kirsten) and he got a motorcycle as a wedding gift! What more could you wish for?! Of course the Kawa was still ugly and Henrique decided to give Wrench Kings a shot on the bike.


A Kawasaki ZX-6R is a bike with an aluminum delta-box frame and an aluminum sub-frame. That provided some challenges! This is Wrench Kings’ first bike with an aluminum frame. Luckily we love challenges and we went to get 5 meters of thick-walled aluminum pipe to build our new sub-frame. The original sub-frame is as square as it is ugly and our aim was to create a bike that looked like an original motorcycle whilst everything has been changed. Welding proved to be a bit challenging, as it was an old aluminum alloy delta-box frame with a new aluminum alloy sub-frame. This required some careful adjustments of the welding equipment, but the result is worth the effort!


It’s a powerful bike and therefore we choose to use tires with a lot of grip: Supermotard rain tires (the Heidenau K73). These tires, together with the wide Renthal handle bars and the sporty seating, make the handling of this bike completely different. Instead of a race bike for highway use, it is a bike for city use and winding roads now.


The aluminum fenders add to the looks and allow for usage in Dutch weather: rain. The seat is made by Toni’s Custom Works and the stitching in the seat matches the profile of the tires. The speedo is a Daytona Velona digital speedo; a cool and clean speedo with enough information for any biker (odo and speed).


The paintjob of the fuel tank was done in-house and because it is a bulky fuel tank with a wide frame below it, the black striping is made so that it looks like the box-frame continues through the fuel tank.


The original colors we had in mind for this fuel tank were vintage red, white and blue. But then Henrique walked in, wearing a green jacket and a green jumper and his only comment on our color choice was: “And what about green?” So green it is!


Kawasaki Ninja Tracker/Fighter Specs

All in all, the following modifications were made to this bike:
• Custom sub-frame
• Custom seat (www.toniworks.nl)
• Custom bracket for the electronics
• Relocated electronics
• Custom paintjob
• Powder coated frame
• Powder coated rims with Heidenau K73 Supermotard rain tires
• Renthal handlebar
• Brembo brake leaver
• Stainless steel brake lines
• Biltwell Thruster grips
• Reno style headlight
• Bates style tail light
• Aluminum front and rear fender
• Built-in turn signals in the original RAM air-inlet holes
• Tiny bright led turn signals at the rear
• Custom Perspex covers (of course with our name engraved!)

Pictures of this bike are taken by Bas Duijs, our favorite photographer. By the time the police came by to chase us off the runway, we had enough pictures taken. Some good old fun! What an awesome location for a shoot! I wish we could have used the runway to have some real fun with this bike! The pictures were taken at the airstrip in Soesterberg. It used to be a military airbase once, but as it is Holland, it is converted to a national park with a bicycle path.


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  1. OMG. Fenders, blinkers, mirrors. And all the custom builders said it couldn’t be done!

    Only one question. Does this bike have a right side? I’d love to see it.

  2. A simple bike but looks well finished

  3. Hey!
    Looks awesome. What do you do with the coolant expansion tank??

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