Very nice!

Nice bike hobot, what size is it? More information?

Gorgeous. Looks like it should have a dustbin fairing though.

GRM 450 wrote:Nice bike hobot, what size is it? More information?

Unless I am very much mistaken, it is a 250cc ex works twin.

I was certain I could find a good link with information on this machine but was completly unsuccessful!

I have a friend who could tell you everything about this machine down to the air in the tyres but he's not about at the moment.

Im 99 % sure it is a 250cc Renmax. World champion in about 1953 (or 54??) They were simply astounding machines and routinely set faster times than the 350 class. They completly destroyed the opposition and moved the design and performance of race bikes ahead a complete generation.

When the factory withdrew from full racing this bike was followed by the production based Sportmax which again won the 250 World title in 55 56 ??? . The Sportmax had an eccentric operated camshaft.

NSU were the biggest bike manufactuers in the world around 1950 and set many worlf speed records including the first motorcycle to go over 200 mph.

johnm wrote:
NSU were the biggest bike manufactuers in the world around 1950 and set many worlf speed records including the first motorcycle to go over 200 mph.

All good info John, but we'd have to point out that mopeds were a very large part of that production. Nothing wrong with mopeds if thats where the market is - didn't Vincent very successfully market a rebadged (?) 'Quickly' or similar.

A drawing of that NSU engine above was in MotorCycle or similar - why settle for one set of bevel drive gears when you can have 2 ?!! Someone here has a cutaway version of the SportMax engine, which you can turn over and watch the 'conrods' operating the cam gear. Very clever system, and apparently almost indestructible. Cheers.

Yes Quicklys many were. plus scooter.s etc. But the bikes were very advanced

My friend is a bit nuts about them even by motorcyclist standards. He has 50 plus NSUs including maybe 20 Maxs and Supermaxs = the 250 street bike. He also owns a genuine Sportmax motor. Evidently each machine had a spare motor (25 bikes 50 engines ???) He own the spare engine of the Rod Coleman machine which came to NZ in the 1950s. He raced it and replicas for several years in the NZCMRR series.

He missed out on the real complete Sportmax machine in about 1972 because he was a poor student and was about $1000 short. The bike is now in Japan i think and it would be worth over $100,000. He still cries about it today !!! At the time it was owned by Tommy McCleary in Christchurch NZ.

The Renmax would cost who knows $250,000 ?

He also has a cutaway Max engine which he takes to bike shows and used it when he was a teacher.

Vic Willoughby, Technical Editor of 'MotorCycle' wrote an extensive article on the NSU Rennmax Twin and Dr Walter Froede the designer. It took the 250cc World Champions crown in 1953 and then 1954 off Guzzi after all. And was setting lap speeds faster than the 350 7Rs and Manxes.

He mentions the phrase "a more scientific approach to design" very early in the article, along with mention of 27 bhp @9000 rpm (for 250cc) early in 1952. By 1954 was giving 39 bhp @11,500 rpm and max speeds of 125 mph at the IoM and 90 mph laps- dolphin full fairing.

Also mentions a large number of facts and figures which had been investigated - 37% of the actual developed power was lost internally to produce that 39bph. And mentions 26 gal/hour oil circulation, a fair bit by even modern standards...
Cheers.

A college buddy had a SuperMax for a while. I'd never seen an OHC engine where the camshafts were driven by connecting rods. When my Dad first started work as a wholesale hardware rep (after the family store closed down) - about mid 1966 - his first company car was an NSU "Prinz".

It had a 1.0-liter engine that looked like 4 Supermax engine lined up in a row. The company found them to be maintenance intensive and sold them all off, replacing them with Ford Cortinas. It was an interesting car - looked like a shrunk-down Corvair. It was rear engined and aircooled like the Corvair, but in-line 4 rather than flat-6.

Those conrods to drive the cams are rather unusual in the bike world, anyone know any other maker who has tried it ?. Wonder how they compensate for temperature expansion ?

Didn't the Munch Mammot use an aircooled NSU 4 engine out of a Prinz ?
http://www.motorcyclespecs.co.za/model/ ... ts1200.htm
Fast, shame about the styling.....

My first car was a 1962 NSU Sport Prinz which was pretty rare here in the USA. It had a 2 cylinder engine that made maybe 36HP on a good day. Was able to keep up with the Volkwagen bugs at the time though.

http://www.nsu4.nl/english/e1ultramaxca ... ystem.html

Heres a link to an explaination of the eccentrics and some information on the machines it was used on

Came onto this post a little late but had to jump in at the end - my first bike was a NSU supermax and I rode it everywhere. Amazing machine but, over the years, it got modded a bit and I finally sold it to a friend of mine so I could buy a A10. He promptly ran it out of oil and I reacquired it and lo these last 45 years it has been sitting neglected outside. I keep telling myself I need to at least salvage that outrageous lump of engine and clean it up for display but I fear if I get too close to it and see the actual present condition, I'll do myself harm. But oh, the memories. When walking toward that first bike, anticipating the sound and ride, a simpler time.

The pictures are no longer available but I have to imagine that it's a SportMax if it's a NSU racer. Someone commented on it likely being a twin but it is most likely a single.

I have a 59 Maxi which is a 175 single with the same cam drive mentioned in the thread. While the bike is rough, it is complete and only has 500 miles on the odometer. It appears that the mag packed it in and the owner just set the bike aside. It's one of my future restoration proje2cts. Would love to have a SuperMax, but I think the Maxi is more rare. The downside is that there are a lot more parts available for the Max and SuperMax than there are for the Maxi. I'm looking for replacement engine side covers as the old ones are pretty dinged up. E-mail me at SMinn560sl@aol.com if you know of any!