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Two Wheels Magazine dubbed it 'Australia's Fastest Chair'.
"The DPA-Laverda was the outfit no one really thought would work. It was a
completely new design with innovations which made it by far the most
sophisticated in Australia.
And it works.
- The World's best sidecar
The DPA was designed by John Bennet, who started Headmod in Melbourne several years ago, and powered by a near stock 1000cc Laverda engine. DPA is the name of the new venture Detail Products of Australia, owned by Bennet. The only changes from standard on the Laverda were bigger inlet valves and facing the cam.
And with that, the radical chair swept the hotter than hot gaggle of Kawasaki and Honda Fours all bored to 1000 to 1200cc.
The Project began when John Bennet told Dennis that he could build him a sidecar which would be impossible to beat. Bennet had worked Dennis’s Honda Four outfit to the limit. The frame simply would not take anymore engine stress and the cost of new mods to the bike were prohibitive. So Bennet began the design of the outfit which cleaned up the series with only Bob Levy as serious competition.
Now Skinner is eagerly awaiting a hotter factory-prepared racing engine wangled out of Laverda Spa by Stanco Motorcycles, the Australian distributor of Laverda. John Black of Stanco has helped Dennis with free spares and has been instrumental in gaining the small factory support for him with the new engine and special hot parts.
The original engine for the DPA came from one of the standard 1000cc
Laverda's in stock at Stanco's Elizabeth Street shop. The bike was one
of the first three shipped to Australia and was complete with drum front
brakes. Stanco dismantled the bike to give Dennis the engine. The parts
were used later in a crash repair job.
John Black almost immediately began to help Dennis with spares and after the sidecar's early success went to the Italian factory for a new engine and hot high compression pistons and high lift cams. The new motor didn't arrive until August last year which meant no development could take place on the motor, because there was no spare in case the mods failed to work out. So a stock standard engine was used for nearly the entire season.
John Black believes the new hot bits will help Dennis stay ahead of his competition: "My conuterpart in England, Roger Slater get's his 1000s from the factory already assembled with hot pistons and cams and without exhausts. But then, they have much less stringent noise laws in England".
“Slater's bikes will do 225 km/h off the floor.”
Already Laverdas are beginning to carve a name for themselves in local production races. John Black believes that riders will begin to play around with the big Laverda triples as they become more available. “Experimental work can only take place when a rider has a spare motor he can use when his best may be still in bits,” he said.
One of the best features of the DPA-Laverda is still the incredible frame which is believed to be one of the most advanced in the world. South Australian Alex Campbell who raced a 700 Yammy into seventh place at the Isle of Man Sidecar TT told Dennis there were no bikes which were as good as Dennis's.
He attributes some of his success with the standard Laverda to the fact that he has not been running a stressed engine. At 80 – 90 horses there is still miles of room left for development. Dennis thinks 120 horses would not be too much to ask, as the frame is also way understressed, leaving room for more hot goodies. Dennis said that he and John Bennett had decided on the Laverda engine because of the strength of the motor. “Take one look at this crankshaft and you will know what I am talking about” he said, lifting the heavy shaft. “It's like a truck shaft.”
- Early day's, the DPA Laverda drew a lot of comment when it
first appeared on the circuits because of it's radical frame and
fairing. Skinners ability was the final ingredient for success.
The shaft might be strong enough to drive a truck but it is far removed from a truck component in this fine metal work. The front wheel is connected to the frame by a wish-bone link affair made from box section 18-20 gauge sheet steel. There is no headstock, but a new steering device which eliminates any wind-up. Very little steering is necessary on the unit. Power is the main factor and steering is mainly for correction.
A huge Formula One grand prix four-spot disc is used to stop the front Dunlop racing slick. The front brake is activated by the left foot. The back brake is activated by the right hand and clutch by the left hand. Dennis finds that individual brake control is necessary and he has been able to get more control by using the left foot to control the front brake.The rest of the frame is made from 18 to 20 core moly tubing and the whole ring is integral including the sidecar – unlike conventional outfits in which the sidecar is an attachment. Consequently, the sidecar doesn't move anywhere near the amount normal outfits allow. There is also little nose dive under braking or lift at power. The suspension is relatively soft. In fact Dennis has not spun the outfit out or had any bingles apart from tearing the fiberglass fairing while being towed after breaking the chain. “I have spun it sideways but it didn't seem to want to spin any further and it just came back straight,” says Dennis.
- Because of the fairing the DPA Laverda looks a lot bigger than
it's competitors. The fairing pays off on fast circuits like
Dennis has well and truly paid his dues. He won the title twice (previously on his Honda) and has scores of State titles to his name. He is also a former dirt track National Champion. Now at 32, with sidecar passenger of eight years' standing, Bob Curnow, 31, the pair are finely tuned combination. They do little practice together, leaving that to official sessions and racing. Most of the problems are sorted out in the old fashioned seat-of-the-pants tradition.
Dennis doesn't like dyno-tuning much and prefers to adjust his machine to how it feels. He says he can fine-tune his outfit by knowing just how he wants it set up. Whatever, his bike has started a sophisticated side-car business in Australia which in itself is a breakthrough.
To prove a point, at least two bikes have now got the centre hub steering, and others are working on the other DPA innovations. Stanco's John Black is all smiles as Laverda, still a small-volume bike here, is on the map well and truly in road racing."
(END Two Wheels 1977)
One of the factory supplied motors fitted to the DPA had no engine number, only the capacity prefix 1000*, so Dennis stamped his initials on it: DS1. The ignition didn't have a rev limiter and the long straight at Bathurst seemed to go on forever allowing the engine to rev well beyond the limits of its components breaking a conrod that smashed through the front of the crankcase.
Another engine from the factory came without engine numbers at all and was roughly enscribed 'D. SKINNER'. The barrell's cast-iron liners were replaced with Laverda 750 liners and oversized high compression pistons from the Laverda 750SFC were modified to suit the contour of the combustion chamber and maximise the squish band of the head.
With the head having large inlet ports feeding extra large inlet valves and small exhaust valves, it created incredible torque and high horsepower.
Reportedly fueled by a Methanol, perhaps mixed with a little bit of Nitromethane, it was a Laverda 3 cylinder engine that carried the DPA duo to victory in the Australian Championships against the Japanes multis. This engine waits safely under the workshop bench to be rebuilt to it's former sidecar performance dominance.
There were many people associated with this machine on it's journey to victory. Iconic racing names like John Bennet, John Ferris, Ian Chugg Alan Mawner, Ken Girvan and others.
In a quirk of history Dennis Skinner's father George modified the mold of DPA's large fairing, and gave it a second life covering the secret innovations of the race winning Honda 6 cylinder sidecar dubbed the Yellow Peril, after a well known contraversial Melbourne sculpture of the same name.
The Yellow Peril was a Push/Pull lever steering, aerofoiled NHR Sidecar. A radical and innovative example of engineering and thinking 'outside the square' built by Neville Hazelman Racing. It was so incredibly fast, so much quicker than anything else, that the FIM summarily banned it.
The DPA sidecar was eventually sold to the the Lamble brothers sidecar team. Herbie swapped the chain drive to the other side and fitted a 1200 Kawasaki engine into the DPA Chassis. Out onto the track it went, and continued to win races.