I normally view the term classic with a deal of fear and loathing usually reserved for such things as maniacal ministers of transport or rabid looking dogs growling in motorcycle breakers (to comment on the relative intelligence of these two nuisances would probably invite an outraged letter from the RSPCA).
Having owned enough British bikes to realise that the breed usually encompasses a dreadful piece of engineering, evidently haunted by malevolent spirits, intent on breaking both my ankle and my bank account, when I see. prices of over a grand for bikes that aren’t even in good running order I just feel a little sick.
Being a little too young to have experienced British bikes when they ruled the world, my ownership of such devices has, by necessity, been limited to old Triumphs that have suffered at the hands of half a dozen or more owners, often been tuned and equally often bodged together with parts that had seen much better days. Their only saving grace, back in the early seventies, was that they could be bought for a couple of hundred quid and responded quite well to being thumped with a large hammer when they went wrong.
The secret was to run them just on the right side of self destruction, for the horror story evoked by actually stripping them down meant either an expensive rebuild or a couple of weeks slinging them back together, trying to make the disturbed bits actually work again. In an oblique sense, the Triumph twin engine could be termed the classic British vertical twin, but as the design was only just about acceptable back in the fifties and the rest of the British stuff was so bad this isn’t much of a compliment.
It is ironic indeed that if you modify a British twin into a usable and practical machine (which is either a very expensive or time consuming exercise) then all the classic collectors would look upon the non-standard modifications with horror. As the National Motorcycle Museum provides an excellent forum for viewing original British motorcycles, I can see absolutely no justification for retaining shoddy engineering on bikes that are actually ridden.
The truth about British motorcycles is that they are ideal devices for people with more time than money - if you can spend a couple of months rebuilding one to a decent specification and a couple of days a month maintaining them, then you’re onto a viable proposition. Unfortunately, the greed of the people who own these bikes and the silliness of the people who pay excessive money for them, means that if you have more time than money you're never going to be able to afford one.
Motorcycle enthusiasts are always claiming that motorcycling is a classless pursuit, the sheer enjoyment of riding motorcycles breaking down barriers, but when it’s so difficult to get hold of old machines at reasonable prices that have the potential for conversion into reliable and practical hardware, then the whole scene becomes more than a little sad. Look, don’t get me wrong, I think a sixties Bonnie looks really neat, sounds lovely and has a useful amount of mid-range performance, as well as commendably low running costs (until the engine blows up), but the basic design is so unsuited to taming the massive vertical twin vibration that major work has to be undertaken to make it practical. And much the same could be said of various BSAs and Nortons.
The only British manufacturer to come close to making a decent job of the engine design was Royal Enfield, just before they went bankrupt. And for sure lots of British motorcycles had bags of character, but then Hitler was probably quite a character too, so it’s no good trotting out that old excuse for self destruct tendencies. Owning a British bike can be quite an experience but defining them as classic and selling them for silly money is just a waste of potentially good motorcycles. If I was shoved in a corner with a shotgun rammed halfway down my throat, I might admit to once having owned a classic motorcycle. Naturally, this wasn’t British (as those that are classics I couldn't afford even then) but from those inscrutable Orientals.
The object of my affections was a ten year old, 1967 Honda CB450 - a device that: was ruined when reincarnated as the CB500T (although there were enough basics left in in this form to provide a reasonable form of hack transport, but don’t confuse two for all their similarities). As someone who was brought up on a Honda CD175 and had a disastrous flirtation with a Triton, the CB450 was natural fodder for my motorcycling ambitions which, for reasons we won’t go into here, centred around big vertical twins. I was happy to find all the 450 required of me was an oil change every 750 miles and a modicum of care with the throttle whilst engine was warming up (if revved the balls off it before the oil had circulated it‘d knock out the camshaft bearings quicker than a Triumph twin would start leaking oil at the pushrod tube seals).
Like many of the other sixties Honda twins the engine was a tough old hunk, whose internal engineering purity was reflected in its external lines - it looked massive, dominated by the DOHC cylinder head. Short of stroke, with valve timing extreme enough to push air through the inlet when turned over by hand, the engine could run up 10500rpm without imploding (although you could take it to 12000 in the lower gears if you like really punishing the motor), valve bounce eliminated by fitment of torsion bar springs operating through rockers to the valves.
The cams operated through a set of rockers mounted on eccentric shafts, with the adjusting screw and lock nut on the outside of the engine - this would have made setting valve clearances a cinch had not Honda demonstrated the precision of their engineering by specifying extremely small valve clearances. Although rumours abound concerning the way the torsion bars snapped, this usually only occurred when they were reassembled incorrectly. No, the real weak point was the small end bearing that was part of the non-detachable con-rod. Once this started to wear, the piston would flap about, taking out the rings.
Luckily, this needed a combination of high miles and abuse before it occurred. Spend an afternoon balancing carbs, setting ignition timing and valve clearances (all with minimal tools) and the engine would tick over between 500 and 600 revs with the kind of quietness that defied expectations of air cooling and highly tuned motors. The pistons moved out of phase producing perfect primary balance, a torque reaction along the crankshaft that shook things about at low revs, and an off beat exhaust that snarled wonderfully above six grand and on the overrun. 43hp at 8500rpm was claimed, which equated to a maximum speed of a tad under 110mph and a fuel consumption of at least 70mpg.
What we have here, is an engine design so far ahead of its time that it left the Brits looking like vintage relics and one, that in terms of overall usability, Honda have still to better over twenty years later. Between 30 and 90mph, the bike was an absolute delight to use - stick it in fourth and growl around or drop it down a gear and really screw it from the power band up to maximum revs. It really was a ball to ride at these speeds.
Rather than demanding something back in return from the rider for such a sporting nature, below six grand, the CB450 was commendably tractable and climbed steep hills in top gear with just the merest hint of throttle, albeit with little hope of acceleration. Only in town did things become a little nasty, with a clutch that dragged the longer the bike had to suffer the traffic, the cable needing continual adjustment.
Until the small-end went, the Honda provided years and years of fun at minimal expense and with a degree of style and individuality (well, it was rare and had a weird, hump-backed shape petrol tank) that should’ve demanded much more than the £160 I paid for it back then. Of course, the suspension was horrible but easily modified or replaced, and it was a bit heavy at 410lbs.
Anyway, the engine has to be the classic Honda motor. Its bottom half was scaled down and formed the basis of the late sixties/early seventies 250 and 350 twins, that sold in such huge numbers all around the world. Its DOHC top end gives the precision of a Ducati Desmo head with much simpler maintenance. The combination of the two provided a mix of performance, economy and reliability that, shockingly, has yet to bettered by any other Jap twin. And you can still pick one up for a couple of hundred quid.
Bill Fowler
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