Over the years the Wankel rotary engine has been, paradoxically, the best and worst alternative to the good ol’ gasoline burning, reciprocating piston engine. Felix Wankel’s concept has shown great promise since its introduction in the 1950s and it has found its way into a wide variety of vehicles. All of which have ended up as, at best, curiosities. Which brings us to the Dutch Van Veen OCR-1000 double-rotor superbike, which is likely one of the best rotary-powered motorcycles, and certainly one of the rarest.
Rotaries are one of those engineer’s wet dreams that is full of promise and has the potential to revolutionize an industry – on paper. It’s light. It’s compact. It’s extremely simple and has few moving parts. It’s far more efficient in terms of power to displacement and has far fewer friction losses than a traditional piston driven four-stroke. It was touted as the future of internal combustion, a better way to burn hydrocarbons that would render the antiquated reciprocating piston engine obsolete.
In reality the rotary is indeed a very efficient design in terms of power vs weight and displacement. A small displacement Wankel punches well above its weight in terms of power, almost like a two-stroke (though it depends on who you ask and how they measure the displacement of a rotary - opinions vary). Problem is it is not efficient when it comes to fuel or oil consumption – that’s where it REALLY punches above its weight, sucking gas like a far, far bigger engine… with an oil-burning problem. Economy and clean emissions are not the fortes of the rotary.
Then you get into long-term reliability issues. While the lack of moving parts and complex systems contributes to admirable simplicity (engineer’s wet dream, remember), what DOES move sees significant wear - specifically, the apex (rotor tip) seals, which remain a major hurdle. The triangular rotor wobbles through an oval chamber, with the four stroke cycle occurring in the pockets created by the flat sides of the rotor as it rotates. The tricky bit is keeping the narrow tips of the rotor sealed against the casing. Up until recently the rotor tips tended to wear quite quickly, which causes the mixture to leaks between the chambers, necessitating regular rebuilds. Very careful maintenance and running procedures are needed to ensure longevity, even in modern rotaries – which are produced almost exclusively by Mazda, who remained stalwart defenders of the Wankel until they recently had to stop production due to tightening emissions standards.
Of course, the whole concept of the rotary sounds ideal for motorcycles. Sure, it’s not super economical and needs to be rebuilt semi-regularly – but compared to a two stroke or a high-strung four-stroke motorbike that’s nothing new. The compact size and high efficiency of the design makes it ideal for application in a two-wheeled contrivance.
Reality has left a lot to be desired.
It was not for lack of trying. There were dozens of rotary-engined motorcycle prototypes from just about every manufacturer, and a few odd models that made it to production. The best known was the 1974 -76 Suzuki RE-5. Norton produced a series of reasonably successful models from 1984 to the mid 1990s. There was also the much less successful (actually, quite terrible) DKW/Hercules W2000 of 1974-78.
Then there was the Van Veen OCR-1000, arguably the best rotary motorcycle of the 1970s.
Henk van Veen was the Dutch importer of Kreidler two strokes, and prepared bikes for the 50cc GP category. He became well known for his work in Grand Prix racing in the 1970s but yearned for success in a big-bike category. Thus he began the OCR project in early ‘70s, with the aim of building a Wankel powered superbike with thoroughly modern technology. The first prototype used a Moto Guzzi V7 frame mated to a Mazda rotary engine.
Several factors were working in Van Veen’s favour. While rotary technology was still relatively new in the 1960s and 70s, it held a lot of promise and there were many companies experimenting with the newfangled technology. However, NSU (who employed Felix Wankel and held the patents on rotaries) maintained strict rules regarding the design and production of rotaries by outside firms, and demanded exorbitant royalties from those who wished to build their own rotaries. This was (part) of the demise of the W2000; the restrictions were relaxed if your design made no more than 30 hp, so the Sachs engine in the W2000 was tuned below that. The RE-5 only made a claimed 62 hp, and weighed over 550 lbs, which put it behind most four-stroke Superbikes of the 1970s. Up until Norton started making high performance rotary bikes in the 1980s, you didn’t pick a Wankel-powered ride for world-beating performance.
Unless you bought an OCR-1000, that is.
After the warm reception of the prototype, work began on a more polished and advanced production model. The timing appeared right as well. In the late 1960s NSU and Citroen formed a partnership to manufacture engine in Luxembourg called Comotor, which was set to build an advanced liquid-cooled double-rotor engine for the Citroen GS. The engine, unveiled in 1973, displaced 996cc and pumped out 107hp and an impressive 103 lb/ft of torque in a compact package that weighed just over 200 lbs. It was designed for light car applications, and was a marked improvement over the older NSU and Mazda designs. Van Veen saw the potential for it to power his OCR, and set about obtaining a supply of engines from Comotor.
The OCR was given a restyle and a new design was built around the Comotor mill, with a Porsche-designed gearbox mated to a drive shaft, and various modifications to suit a two-wheeled application. The result was a clean, futuristic bike that was dominated by a massive, matte-finished engine block. Component quality and finishing was high, and subtle details abounded – the exhausts featured rectangular exits with bevelled canisters, the fork legs repeated the rotary logo found on the engine cases, and the bike was suspended on cast wheels with hydraulic disks front and back (rare at the time). Van Veen set his sights high, and wanted to build the ultimate superbike in terms of engineering, performance, and build quality.
So the OCR-1000 looked to be the ultimate rotary powered motorcycle – it was nice looking, well built, and quite powerful. There were, however, some issues.
The most notable was the price. It fluctuated over the years, but was roughly equivalent to 15000$ US. That meant that, aside from being prohibitively expensive, the OCR would always suffer the “but the price” reviewer mentality – it was a good bike, but it wasn’t two-BMWs-worth good and the period reviews were quick to point this out.
It was also heavy - almost 700 lbs. That’s fine if you are talking about full dress Harleys, but not so much for a bleeding edge technology bike with sporting intentions.
Then there were the engine issues. Despite showing great promise the Comotor engine was plagued with issues, both in the Van Veen and the Citroen it was designed for. The GS Birotor sedan ended up being a complete failure, with only 874 produced – almost all of which were bought back and crushed by Citroen so they wouldn’t have to keep producing spare parts. Comotor would shamble on for a few more years, eventually going under in 1980.
The Van Veen was more or less finished by 1979, but “production” of a few more bikes continued until 1981. A total of 38 machines were built, and after the company shuttered the tooling and spares were bought by a Dutch rotary specialist.
But that wasn’t the end of the OCR-1000. In mid 2011, a surprising announcement was made. Two Dutchmen, Dirk Knip and Andries Wielinga had bought the mothballed tooling for the OCR and would build a final run of 10 bikes. Thus the new 2011 Van Veen, same as the old Van Veen, was born. A brand new-old OCR was yours for the price of 115000$. No I did not accidentally add a zero. Makes the original 15000$ price tag seem quite reasonable in comparison.
The 2011 OCR was revealed to the press and limited demos were offered to a few journalists. Hans Koopman from Motorcycle Classics magazine had this to say:
Swing a leg over the seat and two things immediately stand out; the vibration-free rotary engine and the perfect seating position. The high handlebars combined with the not too high footrests provide the relaxed attitude you expect from a touring bike. Another surprise is the bike’s low-speed handling, where the bike’s high weight disappears like snow in the sun. The handling, even compared to modern bikes, is glorious, much better than that of big touring bikes of the late 1970s like the Kawasaki KZ1300 or Yamaha XS1100.
Out on the road, the Van Veen rides almost like a Honda. Shifting, braking, handlebar switchgear, everything is as you’re used to on any modern bike. The mirrors are clear, the ground clearance ample, and you never notice that you’re riding a rotary-powered bike, because the power packs neatly, just as you expect from a modern four-stroke. The specifications indicate 100 horsepower, but we didn’t get to use it all. On a few straights we took the engine to just above 4,000rpm (redline is 6,500rpm), where the engine starts to reveal its true nature, pulling aggressively.
The review is positive and polite, though for over one-hundred-thousand bucks you’d hope it was passable. Clearly, the new OCR is intended as a rare curiosity for the wealthy collector rather than an attempt to revive Van Veen production. The fact they are only making 10 should indicate that. Some improvements are being incorporated into the motor in the hopes of eliminating the teething problems of the Comotor unit that plagued the original series of bikes. In fact you get a two-year warranty, and spares support. However there are no plans to continue production after the 10th bike is finished.
The Van Veen started out as an attempt to build the world’s finest superbike, a rolling engineer’s dream with stunning performance. In the end it became a curious exercise that showed great promise, but was plagued by the usual rotary shortcomings and a prohibitive price tag. Henk van Veen built one of the best rotary powered bikes of all time, but few were ever able to appreciate the effort, and even then he was unable to circumvent the problems inherent in early Wankel motors. The 2011 “revival” of Van Veen motorcycles adds a fascinating footnote to the story, but with a six figure price tag it doesn’t bring Henk’s concept any closer to the average rider. So the OCR-1000 remains a classic odd bike – weird, ambitious, impressive, but ultimately doomed to obscurity.
A video of the "new" OCR being unveiled
Motorcycle Classics review of the 2011 OCR-1000
Optimistic 1974 Popular Science article on the Comotor/Citroen GS Birotor
Detailed Wiki article on Wankel engines
Motorcycle USA on the Hercules/DKW W2000
Motorcycle Classics on the Suzuki RE-5