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RAD MOTORRAD. Motorworld’s 1939 NSU 601 OSL


Posted on April 23, 2017 by Andrew in Classic. 14 comments

Picture the Audi logo in your head. Hopefully, you’ll be seeing something along the lines of the Olympic rings. Being a company that was formed by a conglomeration of four different pre-existing entities, these circles were designed to indicate a union. And one of those circles was the German NSU Motorenwerke AG. While they produced cars for much of their life and helped to make the rotary engine famous, motorcycles were their stock-in-trade. And some would argue that the WWII 601 NSL was their finest hour. Here’s a mint example from Russia’s Mortorworld.

NSU began life as the “Mechanische Werkstätte zur Herstellung von Strickmaschinen”, a knitting machine manufacturer started in 1873 by Christian Schmidt, a technically astute entrepreneur. Motorcycle production began in 1901, and world class racing motorcycles were entered in events in Europe, the UK, and USA from 1905. In 1907, British brand manager Martin Geiger rode an NSU in the very first Isle of Man TT, finishing in a respectable 5th place. During the 1930s, and again in the mid-1950s, NSU was the world’s largest motorcycle producer.

In the early 1930s, the NSU company set itself the none-too-easy task of developing an engine design with a truly innovative valve train; the OHV or overhead valve configuration. A very new and completely innovative solution at the time, it was design to overcome the disadvantages of the sidevalve engine: poor gas flow, poor combustion chamber shape, and low compression ratio, all of which result in a low power output. This work was headed by Walter Moore, an engineer from England who had been previously working at Norton.

The decision to improve their own engines was less of a masterful internal decision by the company, and more of a severe butt kicking that was handed to them via a series of competition losses against machines from the BMW and DKW factories. Installing twin-cylinder engines on their machines, these companies were one cylinder up against the NSU motorcycles. Stuck using mostly single-cylinder engines, they found themselves being easily outpaced by the competition’s technology.

Once a reliable design had been tooled-up, produced and tested, NSU was quick to flick the switch on new OHV-equipped racing models. Specifically, racing engines with 200, 250, 350 and 500cc capacity were rubber stamped for immediate production to try and earn back a little much-needed racing street cred.

Considered the cream of the OHV crop was the NSU ‘601 OSL’ that was first available for purchase in 1938; the 562cc engine pumped out a very healthy 24 hp at 3800 rpm. The “OSL” abbreviation loosely translates as “Overhead Racing Luxury,” and the look of the non-military version of the motorcycle was magnificent indeed, what with its tall, finned aluminium cylinder head and the fancy-looking chrome-plated tail pipes.

With Nazi officials impressed by the bike, the model 601 OSL was readily adopted by the equipment-hungry Wehrmacht as Germany prepared for war in the late 1930s. A military version of the model was ordered, featuring a second seat, twin panniers and an exhaust system painted in matt black. Its intended use was as a transportation for couriers and orderlies, which probably accounted for its maximum speed of 130 km/h.

“With Nazi officials impressed by the bike, the model 601 OSL was readily adopted by the equipment-hungry Wehrmacht as Germany prepared for war”

Sticking with a single cylinder, the 562cc engine was powered by a Bosch Magnito and fuelled by the ever-present Amal carb. A four-speed gearbox and multi-plate clutch got the thumps to the rear wheel, which was unsprung. Front brakes were drums, and the overall frame was a tubular design. And the classic’s 185kg (408 lb) mass and 12 litre (3.1-gallon) tank would take any averaged-sized pilot around 240 kilometres between battles.

Motorworld – Facebook – Instagram ]








  • John Forsythe

    I feel as though the article is incomplete? Tell us more about this thing!

    • There’s surprisingly little about this bike on the web. I’m guessing we may have to hit the books to learn more.

  • Gman

    Pipeburn has jumped the shark. So many great new builders out there and you guys post the same themes.

    • I’m not really sure what you mean. ‘Themes’? You mean classic bikes? How is posting classic bikes ‘jumping the shark’?

      • Gman

        I am not commenting on classics per say. But it seems pipeburn is missing the boat on the wave of new builders out there who are doing amazing work. So I am no longer sure what the brand represents. Hence jump the shark. And let’s face it. That classic is just not that interesting…. to me.

        • Which builders in particular?

        • Soapy Loofah

          Yes, more thin brown seats, missing front fenders and archaic tires. The “modern” builders so often featured have reduced themselves to a level of copy-cat styling that is beyond comprehension. No one will ever look at a chopped CX500 twenty years from now and think – this is what a great motorcycle looked like.

          • Gman

            I don’t disagree with your point about copy cat styling and thin brown seats which is what most site like pipeburn and BE are publishing. But that is not what I am refering too. But I disagree and can point to several CX500, as I am sure you can,that will stand the test of time and that were better conceived than the originals.

          • Soapy Loofah

            I cannot accept that challenge – I honestly know of no CX500 that will ever be considered as timeless as this bike. But…I would be pleased to be shown that I’m wrong.

          • Gman

            Soapy,
            I see you are hooked on the classics. Your reference to “this bike” is a give away. Well I am no hater and could understand your allegiance. But elegant it is not. First off this is a war bike and as with the Harley’s of the same era Elegance was not the aim. The 1939 Benelli 500 was leaps and bounds more esthetically pleasing than this one. But I feel you. One is either a man who wears Italian shoes with his tuxedo or cowboy boots. One likes front fenders or they don’t. Beauty is in the eye of the beholder. As for the cx500 one need only look to Auto Fabrica. Having said, hindsight maybe I was too harsh with PB, after all this is a Motorcycle website and diverity is Important. And I respect all things with wheels and motors. My comment does not stray to far from your idiom. The industry keeps putting forth skinny seats, dented tanks and bubble cowls and none is differentiated by another. I could go on all day. Hell I could probably write a proselytorial column on the subject. Cheers!

          • Gman. Shoot us an email with the bikes. Very interested in seeing them. Mail@pipeburn.com. Cheers!

          • arnonymous

            I just have to add, i dont agree with Gman. I think you are showing amazing bikes, obviously some more than others but thats a matter of taste!
            And if once every 20-30 bikes you show a classic and with a nice background story, showing how modern bikes evolved to what they are now, then thats amazing, and i completely support it!
            Im just so annoyed by all the people that seem to posses the knowledge of absolute beauty; You know the link to this article shows a picture, dont like it, dont click it, There are more people coming to this site not everything should suit everybody.

  • Why don’t they make exhausts like that anymore…

  • guvnor67

    That engine is sexy. Back in the 80’s when I was stationed inDuisburg, Germany, my then girlfriend showed me photos of an NSU that she and her ex had been restoring. They split up, he kept the bike, and I believe the restoration was abandoned due to the fact he’d rather empty bottles than turn wrenches. It was a simple looking machine, that like this one just oozed character and style.I like this, a lot.