1958 NSU Supermax


NSU - History and Legacy

First established as (Neckarsulm Strickmaschinen (knitting machine) after the sale of knitting machines sales declined the factory like many others in the industry started producing  bicycles and became Neckarsulmer Fahrrad (bicycle) Werke AG.  When they started building cars in about 1905 they changed their name to Neckarsulmer Fahrzeuge (vehicle) Werke AG.  These names were too long for convenience so most referred to the motorcycles and cars as ‘Neckarsulmer’.  Subsequently that was made even simpler by taking three letters out of the name NeckarSUlm (Neckarsulm is located at the junction of the Neckar and Sulm rivers) to create NSU.  Nice and easy but unfortunately sharing the acronym with another NSU; non-specific urethritis (unlike this NSU, NSU AG products weren’t pox!).

By 1950s NSU were producing more motorcycles and scooters than any other manufacturer in the world and their advanced designs were highly regarded for their elegance, simplicity, function and excellent build quality.  The bikes were fast, refined and comfortable and well able to cope with the poor road conditions of post-war Europe.  It's a measure of NSU's excellent reputation that Honda used NSU designs (with NSU's permission and consultation) as the foundation of their motorcycle empire.

With the declining motorcycle market in Europe NSU concentrated on car production with a highly-regarded range of small cars including the NSU TT, the engine of which went on to power the Munch Mammut, and the NSU Wankel Spider, the world's first Wankel rotary-engined car.  NSU are also famous for the NSU Ro80, a car so advanced its features only became commonplace in the 1990s.  NSU merged with Audi (then owned by Mercedes) and their new K70 FWD small car design ultimately emerged as the Audi 100 under new Volkswagen ownership.  So we can see the extent of the influence NSU had on the motor industry; Honda for motorcycles and Audi/Passat/Golf for Volkswagen.


In the fifties NSU were the first motorcycles to achieve 200mph and from that time NSU still hold a number of land speed records.  NSU won the 250cc World Championship three times in a row: 1953-5, first with the twin-cylinder Rennmax (foundation of the Honda CB72 and Laverda 750 SFC) and then with the Sportmax.  The Sportmax was a development of the Supermax and as far as I know to this day is still the only truly road-based motorcycle to win a World Championship.  They also won many off-road titles with the Gelande (off-road) version. 


The Supermax is the ultimate development of the Max range.  Its 17hp engine gave a top speed of 85mph and its comfortable ride, excellent handling and powerful brakes endowed the Supermax with excellent ground-covering ability.  A key point of difference is the eccentric drive (see photo page) to the valve gear.  It's quiet and reliable and eliminates the major maintenance task of timing chain replacement.  The Supermax’s styling looks a little quaint to modern eyes but in the context of its time the design makes good, practical sense.  The deeply valenced guards would keep Herr Schmidt's trousers clean on the way to work and fully enclosing the chain tripled or quadrupled its life as well as keeping Frau Schmidt's skirt clean if ever she was pillion.  All the electrics are enclosed and out of the weather and the pressed metal frame was cheap and easy to mass-produce as well as being light and rigid.  The large fuel tank gives excellent range and the brakes are large and very powerful.  The front forks have enclosed telescopic elements that,again, are out of the weather and dirt and being leading link can accommodate large wheel deflection over relatively short stroke.  In essence the NSU Supermax was an advanced machine that was easy to ride and maintain.

‘My’ Supermax (some pix here)

My’ example dates from 1958 and was bought by me in October 1989 from Classic Cycle Spares in Taree, NSW.  it was advertised as an unfinished project and the frame had been renovated and painted, the engine rebuilt, the wheels re-spoked and re-chromed and fitted with new Metzeler tyres.  It duly arrived and I was disappointed that it came with no controls or levers and the cold-air box was incorrect.  There were also a myriad other small details to attend to.  I sourced some cheapo second-hand Japanese switches and generic levers and, with hope, fired up the engine only to find the generator wasn't charging and nobody could make it work.  With points ignition and no magneto that was a problem.  Unable then to afford expensive repairs or parts from Germany it was pushed to the back of the shed.  It was regularly wheeled around and the engine turned over so nothing really deteriorated except the ordinary plating job on the rims which now have some rust coming through.

In 2006 I got the guilts and wheeled the machine out into the sunlight again to make a proper effort to solve the charging problem.  Nothing could be done with the existing bits but I finally came across a German company that makes a alternator/electronic conversion kit so with growing hope I bought one and fitted it.  It worked brilliantly and at a stroke made the machine practical and viable again.  I finished off a few things for the RWC and finally, on January 3rd, 2007 it was registered and on the road.

Fettle to the metal

I improved the machine by fitting correct parts like the Overlander muffler, Karcoma fuel tap and a halogen headlight (ex-Honda).  Initially the engine pumped out huge amounts of oil due to crankcase pressurisation so I pulled the barrel off and sure enough number two compression ring was broken, probably during re-assembly back in the ‘80s.  The bore wasn’t damaged so I honed it and fitted a new ring and the problem went away.  Made it much more difficult to kick-start though!  While the engine was out I replaced just about every seal (all but one are standard sizes) and corrected a gear selector alignment problem.  I also fitted new jets and needle to the carburettor and a foam element to the air filter to replace the steel mesh rock filter.  There's a myriad of other things did as well but I won't go into them here. 

Spares aren't a problem, nearly everything is available from German specialists including 300cc barrels and pistons.  I tended to use NSU-Motzke for everything except oil filters which are a current BMW part.  I don't think its ever had a no-expense spared restoration but it looks as though its had things done when they needed it.  The cylinder bore and piston are still the standard size, I couldn't detect any wear inside the gearbox and everything in the top end looks in very good condition.  It's not perfect but it certainly doesn't look like its been attacked by a gorilla with a cold chisel and hammer.  I did have some photos of the insides but they appear to have got lost in the transition from old to new computers.  I didn’t need to touch any of the cycle parts. 

Looking for a new home...

It was a sweet machine and I put a few hundred miles on it and really enjoyed it when I had the chance.  But, all machines have a quirk and the Supermax is no exception.  Because of the way it's designed it's easy, when changing gear, to overspeed the gear selector drum and get a false neutral but once you learn to make gear changes more deliberate it's not a problem because the engine's quite torquey.  Generally I didn’t have a problem with the bike except I didn’t quite fit the machine and couldn’t find a riding position that was just right.  It was also a bit slow in modern traffic, which I found unsettling, which limited the bike’s useability.  The unfortunate thing was I couldn’t afford to keep registered a machine I couldn’t use more often so sadly it needed to find a new home.  I didn’t want to just keep it at the back of the shed where it would fall into neglect again.  I was sad to part with it but glad to see it go to a good home with "Maksi" in Healesville.  One chapter ends and another begins...

...with Moto Guzzi.