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The Kneeslider

Doers Builders and Positive People

MadBoxer Brings Kickboxer Subaru WRX CAD Concept to Life

By Paul Crowe

The MadBoxer Subaru WRX powered motorcycle by Marcel van Hooijdonk of New Zealand
The MadBoxer Subaru WRX powered motorcycle by Marcel van Hooijdonk of New Zealand
Be sure to click on these images to see them full size

It all started years ago, in 2009, when we featured a series of Solidworks CAD drawings by Ian McElroy for a concept motorcycle called “Kickboxer.” The idea was to create a radical, but carefully planned design using the 2.5 liter engine from a Subaru WRX. The drawings were a big hit and quickly made their way all around the world until a friend sent one to Marcel van Hooijdonk down in New Zealand challenging him to “knock one up in the shed.” Marcel, a toolmaker by trade who manages a CNC and manual machine shop, is also an avid motorcyclist and he took the challenge seriously since it showed a combination of things he had always wanted to build, especially a center steering hub. Being a doer by nature, he got an engine case, some tires, spaced it out, stepped back, grabbed a beer and after some long hard looks decided, … “yes, it’s doable.”

MadBoxer stage one - is it doable? Yes!
MadBoxer stage one, arrange the major assemblies – is it doable? Yes!

First order of business was to design and machine the front hub and then he proceeded to design the steering. It was also the first of many challenges from working within the New Zealand legal system so he could get the final design approved for road use. The design had to be changed several times as a result, he had come up with both a cable and a hydraulic steering setup that worked great and looked very tidy, but the mechanical system was the one finally given the green light, and so it went for a number of other parts of the bike. The original CAD drawings could have worked in a world where any design gets approved, but the finished “MadBoxer” you see here, is the one that’s now road legal in New Zealand.

Designing and building the front swing arm and center hub steering was a major undertaking  to get the design right and also to get it approved by New Zealand authorities. Notice the high quality work here. Very impressive.
Designing and building the front swing arm and center hub steering was a major undertaking to get the design right and also to get it approved by New Zealand authorities. Notice the high quality work here. Very impressive.

The system here in NZ is not too bad, you forward your design at the beginning and a panel goes over it approving it or not and identifying any aspects you need to redesign. Then you re-apply and once you have approval you can start, but with inspections along the way. You can make changes as happens during builds, you always think of something you would like to do different which has to then go back to the panel and may need evidence to confirm your design i.e. stress calculations, loadings and load capabilities of items selected. At times its hair pulling but now it’s all done and 100% road legal.

Looks good from all angles
Looks good from all angles

The transmission is a stripped and modified two speed automatic with a torque converter, gear change is accomplished by pushbutton on the left handlebar. There are no foot operated pedals of any sort. Left hand lever is the rear brake, left hand button to shift, I have a hunch a new rider would want to go slow for a bit while he reprogrammed his brain, though it’s probably no more difficult, maybe even easier, than riding an old jockey shift Indian or Harley.

MadBoxer Subaru WRX powered concept comes to life
MadBoxer Subaru WRX powered concept comes to life

Tank and seat pads are from various Japanese bikes, front brakes and coil overs are Buell, but guards, swing arms, steering components, chassis and half the gear box are home made and if you look closely at these photos, you’ll appreciate the huge amount of high quality work that went into those parts.

Getting it to start after all of the wiring was really difficult, all of the electrics and the lithium battery and capacitor are packed neatly under the seat and there was a lot of interference and Marcel says it probably took a good year before it started alone without the aid of a truck battery and jumper cables, which he says was one of those moments that brought a huge smile. The engine is straight out of a Subaru and was rebuilt before final installation.

Subaru really does build motorcycle engines
Subaru really does build motorcycle engines

All CAD design work, CNC machining and TIG welding were done by Marcel. The entire project took somewhere between 5 and 6 years with a few slow periods when designs were being changed, but persistence pays off and the bike you see here is on the road.

Just beginning to take shape, front swing arm and steering coming together
Just beginning to take shape, front swing arm and steering coming together

There were a lot of comments on the original Kickboxer post questioning the feasibility of the design, but everyone was impressed by the idea and many wondered if someone would, or even could, build it. Marcel just answered all of those questions.

This was, in Marcel’s words, a spare time shed project, but what a project! The Kickboxer CAD drawings inspired a real doer to look them over and say, “Yeah, I can do that,” and then go on to prove it. Marcel deserves a lot of praise for his ability to transform that CAD drawing into the finished bike shown in these photos. Great work, Marcel!

Marcel van Hooijdonk, builder
Marcel van Hooijdonk, builder. Notice the Kickboxer Solidworks drawing in the window.

Posted on May 25, 2017 Filed Under: Motorcycle Builders Tagged With: Marcel van Hooijdonk, Subaru WRX


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Comments

  1. Felipe Zapata says

    May 25, 2017 at 11:52 am

    That is one wacky-looking thing. I keep wondering where the driver puts his feet.

    And that front wheel connection!

  2. Dave Ryskamp says

    May 25, 2017 at 12:50 pm

    Amazing workmanship, I’m really impressed, the amount of work to pull a project like off is huge, he really deserves kudo’s for sticking with it and finishing the job. Beautiful! Must be a rush to ride, power to weight ratio must be incredible.

  3. eric says

    May 25, 2017 at 3:56 pm

    That’s thinking outside the box

    • Steve says

      May 25, 2017 at 7:57 pm

      I see what you did there.

  4. Liam Venter says

    May 25, 2017 at 6:02 pm

    Marcel is a Genius. The quality of the finish and workmanship is just astonishing. When Marcel first built this bike it was discovered that the battery box was to small to house a big enough battery to power it’s car starter motor. He contacted me to see if we could supply a powerful enough lithium battery to do the job. On reviewing the requirements I built a hybrid Lithium Ultracapacitor battery for the bike. The lithium cells provided the storage and charge the bank of UltraCapacitors and the UltraCapacitors do the job of providing somewhere in the vicinity of 750 CCA required to drive the starter motor. The Ultrabat lithium batteries have their own internal BMS as all Ultrabatt batteries have and I also designed and built a CMS (Capacitor Management System) to load balance each of the capacitors in the capacitor bank. Works a treat.

    • William Draughn says

      September 7, 2017 at 7:14 pm

      Now see this is interesting. Could you modify the design and manufacture different sizes for other vehicle/motorcycle battery replacements? What are the space and weight savings? What is the cost difference? You already have a design that will crank a Subaru, and plenty of people out there driving those. You can use the crowdfunding sites like a pre-order.

  5. Bob says

    May 25, 2017 at 7:40 pm

    I could walk around that, occasionally sit down, and stare at that for far longer than any “Curated” warehouse show.

  6. GenWaylaid says

    May 26, 2017 at 2:55 pm

    The controls layout doesn’t sound that odd: it’s identical to most scooters made since the ’80s. I imagine a two-speed automatic is plenty adequate behind a car motor, and probably works better than the old “Hondamatic” bikes.

    • Paul Crowe says

      May 26, 2017 at 3:23 pm

      Probably true, but not being a scooter rider, I should have said, I would have to start out slow while I reprogrammed my brain. Of course a scooter rider jumping on a bike this size with a 2.5 liter turbo motor under his butt may have an entirely different issue to deal with, not that Marcel will be offering demo rides any time soon.

  7. Paul says

    May 30, 2017 at 2:55 pm

    I really wish there was a video linked so we could see and hear this monstrosity up and running.

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