South African Assault on Bonneville Land Speed Record…

Koos Zietsman Racing Super singles in 1987

Hand made South African 2-Stroke, 500 to take on the flats. 

An Adventure of some note! Bonneville 2024.

Occasionally we bump into some really interesting people. This time round, the enthusiastic gents from Alpha Performance Bike Tyres in Silverlakes gave us a call and invited us for a cup of coffee. “There’s an interesting project on the go as we speak, you’d better come and grab the story…”

South Africa’s Team Matjien and engineer/pilot, 67 year old Koos Zietsman plans to break the world land speed record on a South African made 498cc 2-stroke machine at Bonneville next year.

Ever heard of a partial streamlined?

You can look it up if you like, but as we understand it, it’s a fared bike and the pilots body needs to be visible from the side. 

Not sitting inside, but riding on it, as you would on a conventional motorcycle.

Yes you read that correctly, a 498cc two stroke partial Streamlined built in SA.

Tom Borcherdt on his partial Streamlined BSA

And then, when they remove the bodywork, he can also enter the naked class.

Tom Borcherdt - naked class


There is a little bit of borrowed tech going on.

Koos and the team are using the clutch and gear arrangement from a KTM 690. Nope, not the bottom end, just some internals, minus the starter.

Everything else is being made from scratch, casings, crank, barrel, cylinder head, radiators and exhaust system.

A massive 12v Davies Craig water pump sends coolant through some big radiators made by Universal Coolers to keep temperatures under wraps.

Methanol is to be supplied by a rather fierce 44ml round slide Mikuni Carburettor, complete with an electric pump and a regulator. Methanol is the fuel of choice because it’s stable, the boys have all raced with it and it helps to cool the piston.

Speaking of piston, that’s a Wiseco piston from a CR500. With an 18:1 compression ratio. “Ludicrous” in Koos’ own words.

The guys are actually3d printing a transparent barrel and cylinder head and sending water through it with tiny little balls to ensure that the flow and cooling is optimised.

Koos getting measured and mocked up for the SA built Matjien....


The team is building a hand made steel trellis frame from 30ml mild steel tubing. It’s easy to work with and can be welded on site.

The 17” wheels are courtesy of a CBR, as are the forks. The team has imported a set of Brembo brakes and will be manufacturing the full floating brake discs.

Rake will be at 30 degrees and they will fit a damper up front.

Out back you’ll find a custom Bilstein shock, made in the UK, just for this bike. Tyres are by Michelin, sourced by the friendly guys at Alpha Performance Tyres in Silverlakes. They are rated to 270KPH plus.

They plan to mount the hand made aluminium fuel tank and the engine as close to the centre of the bike as possible in order to keep the weight close to the rear wheel. 

It’s all about finding traction.

Bodywork will be custom made in SA 

The start of the engine design.
Mr Koos Zietsman

Here’s Koos’ take on the records

The interesting thing is that the FIM world records are WAY lower than the AMA records in this class. Maybe we bring back a brace of new records, Maybe racing grabs us by the balls and we come back with lots of experiences and memories!”

Team Matjien. 

That’s the name of the team responsible for this madcap adventures – a team that includes some very impressive credentials:

We’ve introduced you to Koos, lead engineer on the project. He will be piloting the land speed bike in August 2024.

He has roped in 2-Stroke development engineer Neels Van Niekerk. 

Joining them is Gear design engineer, Piet Van Zyl who has experience working on projects for the likes of McLaren F1 cars.

Whilst Riempies is tasked with riding that 500cc 2-stroke bike (go and see that feature in Dirt And Trail), at The Roof, he also happens to be an optronics design engineer.

Hans Fouche is an F1 Aerodynamicist. 

Fox Keet is the CAD designer for the LS498 engine for Bonneville.

The frame design engineer is Jock Pretorius who completed Roof bronze as a complete novice in 2022.

The team is rounded off by Ryan Raubenheimer who is a vehicle dynamics simulation engineer.

It’s  all been worked out really scientifically, we don’t even understand half of what they are doing to get it right, but you need to understand that these are not your average braai mechanics. 

This bike should be the real deal. We look forward to keeping you posted!

LS498 vs CR500 power

1 thought on “South African Assault on Bonneville Land Speed Record…”

  1. Gerry Baillon

    Wow guys, good luck to you Koos, you are an amazing man.
    I hope you are successful in your endeavour .

    All the best wishes to you guys from Spain !

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