Buyers' Guides

Tuesday, 22 January 2019

Loose Lines [Issue 40, Jan/Feb 1993]

As a compulsive reader of magazines I come across various bits of interesting information. For instance, Cessna were proudly announcing their new executive jet, claiming a 20% reduction in fuel consumption whilst increasing power and longevity... and some French company had produced a diesel engined motorcycle of huge proportions; the liberated car engine propelling the mammoth to about the ton and doing better than 100mpg at 55mph!

The mind boggles. Obviously, flight range is important for aircraft and if they make the same kind of major cock up as the Japanese motorcycle manufacturers with regard to fuel economy the plane falls out of the sky and just about every one is unhappy. But to take a Peugeot diesel engine out of a car, stick it in a motorcycle chassis that would shame a Gold Wing 1500 and then deliver over 100mpg! This column has often thought than 100mph, 100mpg were useful yardsticks in determining effective motorcycle design.

Seeing as how this has been achieved using a mammoth diesel that on any sane account should not have come within a mile of a motorcycle chassis, the present, utterly pathetic economy of Japanese middleweights is shown up in an entirely new light. Even were it to be admitted that diesel engines are 20% more efficient than petrol motors, which may or may not be the case (I haven't the time nor energy to dig out the relevant book) the fuel economy of the French machine would still be exceptional when compared with any number of small Jap bikes.

The technology of jet engines is even more remote from yer average motorcycle design, but the point is, as with small hatchback designs, the rewards for building more efficient engines are greater sales. In the motorcycle world those in charge would have us believe that as long as fuel economy is not too horrendous it really doesn’t matter, a bit of flash style and a quoted huge top speed will smooth over any cracks that appear, at least long enough to get the motorcycle out of the showroom.

This arrant nonsense and senseless design all started, as far as I can place it, with those nasty Kawasaki triples. These horrible beasts only had one function in life, to tear off at a blistering pace on any and every bit of straight tarmac. When introduced, stern warnings were issued by the old farts who tested them, along the lines that anyone lacking in a decade’s motorcycle experience would do well to avoid them. This was all grist to the mill and made the bikes even more popular with irresponsible youths and ageing juvenile delinquents ever so intent on letting the good times roll.

Everyone was so overwhelmed by their speed and so frightened by their lack of cornering ability that they had no time left to take note of the way the fuel was being spewed straight out of the exhaust. 20-30mpg was par for the course. After those triples, everyone else who made motorcycles could at least console their impoverished owners with the fact that it was a lot better than the H1.

Or perhaps the malaise began a lot earlier than that. When motorcycling was thrown into the modern era with the introduction of the Trident (stop laughing) and the CB750, economy was the last thing on their manufacturer’s mind. The Triumph Trident, a cobbled together rat-bag of previous Triumph parts and low rent design, was predictably as horrendous on fuel (by late sixties standards) as it was chronically overweight.

The Honda shared the mass problems but economy was almost reasonable, or at least not so unreasonable that owners were going to complain voraciously whilst still bedazzled by its four silencers, disc brake, electric start - and smooth, reliable, oil tight power plant. Any owner used to the self destruct nature of British bikes was only too willing to accept higher running costs if it meant actually arriving at their destination without breaking down.

The CB750 motor was an exceptional piece of engineering if you were either in marketing or production, but its engineering finesse rather than mere multiplicity of parts lacked the cutting edge of the earlier CB450 twin. Honda then followed a path that would’ve sent aircraft manufacturers bust and car makers into the red (as per British Leyland or whatever name it was then trading under). For the next several years engines were detuned, economy reduced and the whole edifice shored up with a dubious style. The pinnacle of these wasted years turned out to be mush like the Superdream, the CB750F and the CX500.

Along the way, those journos not busy trying to land a PR job with the motorcycle manufacturers were either too ignorant to know any better or too far gone on an excess of drugs to give a damn about anything other than going as far and as fast as possible at someone else’s expense. There were one or two exceptions, but fewer than you might’ve hoped.

The seventies were a relatively wild period when the land was not blighted by massive unemployment, and most kids had a pile of spare dosh to spend on whatever took their fancy. Perhaps, this liberation allowed the complete abyss in motorcycle design to flourish?

The other manufacturers concentrated on producing bigger, faster and occasionally tougher machines. Everyone trying to outdo each other in terms of power. Chassis design was as neglected as economy until the marketing departments decided that handling might sell motorcycles... or a cynic might merely form the thought that the spectre of mad American lawyers lining up to sue the butt off manufacturers of motorcycles that threw their riders off at the first opportunity, inspired some rapid re-designs.

Eventually, something approaching capable motorcycles began to emerge from the Japanese manufacturers, notably the CBR600 and FZR1000. But along the way, rather than doing something about economy they decided to compound the problem by designing frames that needed profoundly sticky and ridiculously short-lived rubber to work, as well as disc brakes that either seized up and died or wore out both pads and discs in a few thousand miles. The race inspired look made necessary a totally ridiculous rear disc on anything from a race reptile 125 up.

The only useful bit of design to emerge in the past 25 years, with reference to economy, being the O-ring chain. And even that is slightly flawed by the manufacturers selling a higher grade to the factories than what Joe Bloggs buys from the mail order store... even then, some poor bugger has to rip off the whole rear end to replace the chain (I mean, how bloody ridiculous can you get?).

The alternative of shaft drive is entirely possible but only when you start with the crankshaft facing the right direction, for all other engines the refinement of an enclosed chain is ‘all that's necessary. Even poor old MZs can manage that, but in the current climate of design that ancient two stroke engine adds to the malaise with its appalling fuel economy.

Two strokes are due to make a come back soon with the introduction of direct fuel injection engines, the petrol being injected straight into the combustion chamber after the exhaust port has closed, thus not having the usual easy escape route straight out into the atmosphere. With the inherent superiority of the two stroke cycle, efficient liquid cooling and some sophisticated electronics it’s quite likely that strokers will become more economical than four strokes, even if the latter were designed for economy rather than high speed kicks.

It will probably be by accident that economy improves on OHC designs. The combination of variable valve timing, optimised combustion shape, trick electronics and ultra sophisticated fuel injection combining to produce an engine that slogs like a Panther at low revs and goes for the red zone like a GSXR1100 on methanol. Judging by the slow reaction of the manufacturers, though, by the time they get around to radically improving economy the problem will have been solved by the widespread introduction of electric vehicles... but that’s an entirely different ballgame that I won't go into here.

This whole malaise really does piss me off. In 1992 we should be looking at 150mpg, 70mph; 100mpg, 100mph and 75mpg, 125mph motorcycles. As well as valves that don’t need adjusting, single carbs even on fours (although the four will probably disappear from the motorcycle scene as materials and technology progress) and no damnable rear discs. You would have thought that the massive decline in motorcycle sales, year after year, would have given the manufacturers just the slightest, tiniest hint that they were doing something very wrong. But then they act like typical multinational companies, as if they know better than anyone else... a whole string of expletives have just been deleted in a belated attempt to pander to those who believe the UMG is a family magazine... (ditto!)

Bill Fowler