Monday, March 15, 2010

Dustbin fairings and motorcycle racing: Where’s the future?

Gilera, dustbin fairingMoto Guzzi V8
Back in the 1950s, manufacturers like Gilera, Moto Guzzi and Norton were using all-enveloping 'dustbin' fairings on their racebikes. These fairings were finally banned in 1957 by the FIM...
Norton, dustbin fairingNorton, dustbin fairing

Back in 1957, the FIM banned ‘dustbin fairings’ from motorcycle racing. Back then, various manufacturers used these kind of fairings – essentially an all-enveloping, streamlined shell that must have helped aerodynamics – on their bikes, with a fair bit of success. However, bikes with these fairings became very unstable in crosswinds and in some cases the fairings also interfered with lock-to-lock steering movement.

Over the last few decades, all-enveloping bodywork has occasionally been used on a few prototype motorcycles by some inventors / innovators, usually in the quest for improved fuel efficiency or straight-line top speed. Mainstream manufacturers have, however, steered clear of the erstwhile ‘dustbin fairing,’ which hasn’t been seen on racing bikes or production machines for as long as we can remember.

Recently, with the increasing popularity of electric bikes, battery-powered racebikes and the TTXGP series, there has been some talk of reviving the dustbin fairing on e-racing bikes, since it would, potentially, help with aerodynamics and boost top speeds by a big margin. The TTXGP rules do not prohibit the use of such fairings on battery-powered racebikes, though for many, this remains a controversial subject.

Michael Czysz, the man behind MotoCzysz, recently wrote a detailed piece on his own blog, outlining the possible dangers of reviving the dustbin fairing. ‘What made the dustbin fairing dangerous for 50s-era racing motorcycles, makes it suicidal for 2010 era racing motorcycles. Take a modern motorcycle and add a large side area or fairing to it, and it will be subjected to forces beyond the rider's control,’ says Czysz.

‘Stretch that fairing fore and aft the wheels and you have now increased the leverage of that force and effect. Add additional height and now the fairing is subject to even higher wind speeds that have an even greater lever to lean and pull the motorcycle. More frightening, the rider can only overcome the unwanted change in direction by turning the motorcycle towards its new trajectory as to counter the lean initiated by the wind. This is a very counter intuitive maneouver that takes additional time and real estate most racers do not have,’ he adds.

Britten V10002010 Suzuki Hayabusa
The Britten V1000, with its minimalist bodywork, and the Suzuki Hayabusa, with its streamlined, almost all-enveloping fairing prove that there's more than one way of going very fast...

Quoting various real world examples, Czysz says that motorcycles with all-enveloping bodywork may not remain stable even in a straight line, let alone corners. ‘As efficiency is such a component to electric racing, it is easy to see why someone may think this [the use of dustbin fairings] is a good idea, but I am certain this same person has no modern day racing experience,’ he says.

All of this quite interesting for anyone who loves fast motorcycles. Looking back over the last two decades, we can see that there are at least two schools of thought on motorcycle aerodynamics. One is what you see with bikes like the Suzuki Hayabusa and the Kawasaki ZZR1400 – big, bulbous fairings and the very evident use of streamlining. The Hayabusa, especially, uses the closest modern day equivalent of a dustbin fairing and, hey, it also happens to be the fastest production motorcycle in the world! However, there have also been bikes like the Britten V1000 and various Buell machines, which went with minimal bodywork and which were not only very fast, but also handled extremely well.

So, really, what are the chances of the old dustbin fairing making a comeback to top-flight motorcycle racing? To get some answers, we spoke to Greg Taylor, who has a degree in automotive engineering design and who’s spent two decades in the automotive and motorcycle industries. Among other things, Greg has also worked on Lotus race cars and with Triumph, as a senior engineer, where he was responsible for engineering the TT600’s bodywork, which involved testing the motorcycle in the MIRA full-scale wind tunnel.

I think Michael Czysz is right not to elect to race a ‘dustbin’ type fairing. This is essentially a 1950s design that has had no development in the last 50 years. The dustbin fairing was proven to be a flawed design, so I don't understand why it is being suggested as an answer to streamlining now,’ says Greg. ‘However, I think the phrase ‘dustbin fairing’ is being used as a catch-all term for streamlining and aerodynamic improvements, and its use is confusing what is really trying to be achieved – that is to improve the overall efficiency of the motorcycle,’ he adds.

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The Peraves MonoTracer (above) and the Ecosse ES1 (below, left) are just two machines that have, in their own way, experimented with full, all-enveloping bodywork in recent years...
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‘Don't forget that the original dustbin fairing was a worthy attempt at trying to improve top speeds. The teams using these fairings were trying new technology to gain a competitive advantage, which is what racing is all about,’ says Greg. ‘Do I think dustbin fairings will make a comeback? Hopefully, not in their original form. However, the philosophy behind the dustbin fairing is making a comeback. The motorcycle industry is being forced to produce less emissions, and owners are seeking more fuel efficient machines. The improvement in efficiencies required cannot be achieved through engine development only. Aerodynamics will play a significant part in helping motorcycles to burn less fuel for a given speed,’ he adds.

‘Hybrid and electric motorcycles require efficient aerodynamics far more than their petrol burning cousins. The energy content of batteries is tiny compared to petrol, so an all-electric motorcycle will have to cut through the air very efficiently to travel a credible distance,’ explains Greg.

‘Race series should be encouraging the design of bodywork that reduces aerodynamic drag. Racing will provide rapid development of aerodynamic features that reduce drag, without affecting stability and handling. Modern sports cars feature sophisticated aerodynamic features and devices that provide downforce, with little affect on drag. These aerodynamic features were developed over many years in racing. Motorcycle racing should be encouraging similar aerodynamic developments relevant to our sport, which can then benefit the bikes we buy to ride. I believe electric motorcycle racing will provide the environment for rapid development of aerodynamics. These developments will, no doubt, benefit petrol powered motorcycles, also,’ he adds.

So there you are – the dustbin fairing probably isn’t coming back, though motorcycles – especially high-performance streetbikes, electric bikes and electric/hybrid racing bikes – in the near future may make more effective use of streamlining and aerodynamics. If that means a 400km/h Hayabusa, we’re all for streamlining and aerodynamics…!

See Michael Czysz’s original blog post here, and visit Greg Taylor’s website here
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