The Third Dimension

Cars are like house bricks - they have length, height, and width, in useful, solid-looking proportions. You can do almost anything with a car's styling, because all three dimensions are present in abundance.

By contrast, motorcycles are virtually two dimensional. They have plenty of length and height, but very little width, so proportionally they are more similar to a wall tile. Unlike a brick, tiles are fragile, so before bike designers can set about making the things look nice, they somehow have to create an impression of width.

This may seem a tall order, if that's not a contradiction in terms, but it can be achieved by dividing the bike into brick-like segments, which the eye registers as parts of a three-dimensional jigsaw. You notice the tank, the seat, the cylinders, as separate items vaguely linked together (or, in the case of custom bikes, not linked together at all) which your eye finds easier to comprehend than the complexity of the whole mass. Individually, each of these areas has a solid appearance, so as long as the eye can be made to concentrate on the parts rather than the whole, voila! - you've got width.

Bodywork is just one of many parts which together form the total look of a bike, and the larger the expanse of plastic, the more difficult it is to maintain this chunky, three dimensional effect. Long, uninterrupted body lines tend to look weak, as they emphasize the length without offering any width to compensate. This is the major mistake which car stylists tend to make when designing a motorcycle, because they take width for granted. Cars use long, straight body lines which flow from nose to tail to exaggerate the length and give an impression of speed. Do that on a bike, and it looks as though it will snap in the middle.

Early bikes were akin to cardboard cutouts, with mostly single or fore-and-aft twins, long flat-sided tanks and flimsy, large-diameter wheels. They filled out gradually over the years as speed, and therefore dynamic forces, increased, in turn demanding greater rigidity and torsional resistance. With their cylinders protruding sideways, Guzzi & BMW's always had a head start over their rivals, though the later introduction of transverse fours and even the odd sixes spelled the end of their lateral prerogative.

Having witnessed the demise of the sports car during the late seventies and early eighties, stylists found an ideal replacement in the long-overlooked motorcycle. Most designers had neither much experience with two wheels, nor understanding of the mechanical parts, so they concentrated on the bodywork, applying rules which worked on cars and other products. This was the age of Concorde and Bang & Olufsen, so shapes were flat and linear, lacking any feeling of muscle. Acres of shapeless plastic were allowed to dominate what was previously a piece of precision-engineering, in which the development engineers had long since discovered the laws of segmentation without ever realising it - bikes just looked right that way. For a while, the stylists actually messed up what the engineers had been getting right all along.

It didn't help matters that most design sketches have always been made in side view, meaning that bikes can be overdeveloped in profile before they are really thought out in 3-D. Lately, much conceptual work is carried out on 3-D computer programs, which allows the form to be seen from all angles in animated sequences. The problem is that good designers rarely make good computer operators, and vice-versa, so many studios still find there is no better method than sculpturing the forms directly in foam and clay.

Perhaps the greatest difference in the appearance of bikes over the past thirty years has been an incease in width, leading to a far more solid appearance. Compare a Kawasaki Zephyr with the 1974 Z-1 on which the retro styling was based. The older bike now appears weak and flimsy, thanks to thin tyres, narrow gauge fork tubes and plenty of fresh air between all the components. Back then, the Zephyr would probably have looked impossibly heavy, although it is actually considerably lighter than its deceptively weighty predecessor, as Kawasaki seemed anxious to hide. Back in 1974, weight was mentioned nowhere in the lavish sales brochure.

Clearly, much of this solidity has been due to functional developments - huge improvements in torsional strength (thicker tubes or cast frames) and a higher road contact area (wider tyres & rims) to keep up with increased performance. These days, we're also running on smaller diameter wheels, which help the proportions even more. That's what it's all about - making the bike look strong and beefy from nose to tail, unless the proportions are being purposely mismatched, like on custom bikes. Here, the front is kept deliberately narrow to emphasize the rear, although on the road, the widest part of a Harley is usually the rider.

On sports bikes, fairings which used to be thin sheets of glass-fibre now wrap around to fit snugly against the fuel tank. This emphasizes depth, whilst alleviating the rider's view of the mess inside - I still recall the sight of wires and unpainted fibre matting from those good ole' days on a 900 SS Desmo. Too much integration of components though, and the eye starts to read the bike as a whole entity again rather than a heap of bricks, making it look weak, although colour can be used to differentiate between the parts.

Width is the main reason big bikes have always looked better than small ones, even though in profile they may be nearly identical. The importance of that third dimension has now been understood, and bikes in coming years will continue to get more sculptural and solid-looking. Wider than a Gold Wing? Might be time to apply for that HGV license.

Glynn Kerr, May 2001