CB500 K2 Road Test, Cycle 1973
Historically, the upper limit for motorcyc1e engine displacement seems to have been a function of the effort a man could reasonably be expected to apply on a kick-start lever. And much of the time, there have been at least a couple of mode1s bui1t very near that limit available to the public. That's to be expected. People who ride motorcycles are performance-oriented - one might even say performance-fixated - and the easiest, most certain way to get an almighty straight-1ine surge is with a big engine. Everyone knows that, and that's why any new mega-inch Superbike draws a crowd in dealers' showrooms. Even those who can't afford that kind of bike come to look, just in case their fortunes improve.
Somewhere in that crowd there will be one or two guys who admire the big boomer, marvel over its pure ability to roll up pavement like a rugs have a bank balance that would allow them to buy the thing on the spot - and haven't the slightest interest in owning it. These guys probably are a bit older than the average for motorcyclists, a bit more thoughtfu1, and their minds are subtle enough to appreciate that there is more to riding enjoyment than being able to go fast enough to turn telephone poles into a picket fence. For such riders qualities like agility, smoothness, and balance between braking, cornering and acceleration assume the greatest importance. Speed counts for something with them; they just don't think pure brute muscle is worth what it usually costs in bulk and weight. Riders of this type almost invariably find that elusive point of balance right at the 500cc engine displacement level. Somehow the smaller-displacement bikes always seem to overwork their engines; larger bikes tend to overwork their riders. A 500 does neither, and that has for many years made it the thinking man's motorcycle, the darling bike of those who have a feeling for the motorcycle sport's finer points.
Anyone who has been paying attention will have noticed that the Honda CB-500 K2 Four has become fairly popular, and those who are performance-fixated may wonder why. The bike is after all not overwhelmingly cheaper than its larger and faster brother, the CB-750. An easy answer is that some people are so dollar-conscious that they care about the price difference. You could also say that some people simply do not want to ride as fast as the 750 Four will haul them, or even that smallish riders find it easier to get their feet down on the pavement from the CB-500's seat. There may be an element of truth in all these things, but none can be a deciding factor. There's only a half-inch difference in seat height, about $300 in price, and the CB750's performance is entirely controllable. It doesn't do anything sudden and what it does is purely a function of how you twist that right handlebar grip. But there is a largish difference: the CB-500 is 70 pounds lighter than the CB-750, and that weight difference makes itself felt in several directions.
We can begin with the difference in straight-line performance. The CB-500's engine gives its big brother a 50 per cent displacement advantage but, being lighter and smaller, isn't much slower. It takes another 8/10ths of a second to do the standing-start quarter-mile, and is six mph slower at the lights than the CB-750. That's a sizeable difference, but not as large as is suggested by engine displacement variances. Top speed? Both Hondas will exceed 100 mph quite easily, and once you get past the century mark riding on the public roads - even in Nevada, where it isn't specifically forbidden by law you're out of your skull anyway. In fact, the biggest functional difference between the CB-500 and CB-750 is that the smaller Honda Four has to be twisted a little tighter and coaxed along with the transmission a little more cunningly. You just can't have torque without displacement.
Nobody could object to keeping the revs up when riding a CB-500, as the only strong indication a rider has that the engine's crankshaft is spinning rapidly is the position of the tachometer needle. There is no sense of straining anything even up at the 9,300 rpm redline, nor should there be with the pistons moving up and down less than two inches and piston speed at a modest 3,000 feet per minute where the engine is redlined. But those are just numbers and there's more to it than that. Engineering, even in its most bloodless, computerized form, still is, at least in some measure, an art. So some engines naturally prove to be better than others, despite all the learned diligence of the men with the slide rules. Occasionally all the decisions that go into the creation of an engine prove to have been especially happy ones, and the finished product is especially good. That appears to have been the case with the Honda CB-500 Four. It does not differ much in overall specification from the CB-750 engine designed by the same team. Yet, it has turned out better. Not more reliable, or anything coldly quantitative, but simply better in terms of that indefinable something we call feel. it's smooth, free as a turbine, and you know it's going to keep right on spinning merrily away for as long as the road lasts.
This feeling of willing lightness on the engine's part is complimented by the CB-500's road manners. As noted, the weight difference between it and the CB-750 is 70 pounds. The difference in fee1 is greater. You can't rationally fault the CB-750's handling: the bike never darts about, wobbles or in any way misbehaves. But it never entirely lets you forget that you are straddling one big collection of machinery. You can get it down a twisting road very quickly; it does require that you take a good, solid grip on the scruff of its neck and force it through the turns. The CB-750 is wonderfully steady, but heavy. Not so the CB-500. It is lighter, with a lower center of gravity, and you can get it to go along with your every vagrant whim without a struggle. The steering is nicely light and responsive, and as precise as you'll find with any bike having the Honda's soft, comfort-oriented springing. Freeway expansion strips have a way of changing many bikes' suspension units into what feel like solid struts; the CB-500 takes these without a hitch, as it does those squiggling rain-grooves so many motorcyclists have complained bitterly about. Motorcycle suspensions cannot at present be stiffened enough for good cornering properties without being too stiff for ride comfort, nor softened enough for ride without getting pretty sloppy in corners. Honda has hit upon a compromise with the CB-500's spring rates and damping that is exactly right.
Good steering and suspension don't mean a thing without good tires - which the CB500 also has. They aren't what you'd call roadracing tires, but there isn't a thing wrong with the way they perform within the cornering limits imposed by hardware hanging down along the Honda's sides. With the rear springs on maximum preload which is the only way we set them on our test bikes when we're out fooling around, the limit in right-hand corners (our limit anyway) is reached when contact with the pavement begins to fold the right bootleg. That only occurs with the bike over fairly far and you wouldn't want to be cornering harder than that on the pub1ic roads no matter what kind of tires the Honda was wearing. But you can't get around left turns with anything like the same vigor. Try it and you may land right on your ear, because while Honda has tucked the pipes in nice and close, the bike's stands have not been given the same attention. Both side and centerstands ground hard in left turns, producing an unsettling lurch. We hated this bonus surprise enough to fire up the shop torch, heat the offending structures and hammer them back up where they were unable to give such frightful offense.
Only innate restraint kept us from doing something similar with the CB-500's shift mechanism. In our report on the Honda CB350 K4 (January, 1973) we noted that Honda's engineers had resorted to using the legendary Johnson-rod in the bike's gear-shift mechanism (Johnson-rod: a thing of many sections, loose hinges and joints, held in place by gravity, centrifugal force, springs, necromancy and secondary entanglements). We may have offended Honda with those remarks because they apparently decided to take revenge with the CB-500 we were given to test. This particular bike had an inordinately stiff shifting action, and an overwhelming affinity for the neutrals between first and second, and third and fourth. Most of the CB-500s we have ridden were inclined toward this kind of nonsense; our test bike was just purely dreadful.
There isn't much good to be said for the test CB-500 K2's shift action; the transmission ratios have been altered from those in the original CB-500, and cannot be faulted. Low gear is the same, but all the rest are different, taller, which lends the CB-500 K2 uncommonly high speeds in all of the top four gears. Second gear is good for almost 65 mph before the tachometer redlines, making it astonishingly effective for rocketing past slow-moving trucks on narrow roads. And you can run the Honda past 100 mph in fourth gear-which gives the bike the sort of leverage needed to humiliate mountain grades. These tall, tall gear ratios are exactly right for an engine that spins as willingly as the CB-500. They make the CB-500 Four feel a lot like a genuine roadracer - but without all the noise.
Noise you don't get. Honda's efforts toward silencing have been remarked upon by many, and the company has been particularly successful with its CB-500. Back when jet aircraft was first coming into use, the popular press carried a lot of stories about how the things were spooking their pilots, who could hear all the gurgling and clunking of a plane's hydraulics and the whine of servo motors that had previously been masked by the booming of the piston engine's exhaust and the threshing of its propellers. Honda's CB-500 is a little like that, with strange buzzings and janglings to worry the rider until he realizes that he's hearing things like the rear chain, and the singing of clutch plates when he eases away from a stop. Remarkably, you will not hear the usual air-cooled engine's piston slap, and we marvelled at the silence of the valve train. One would expect at least a slight rattle; its absence suggests that Honda cams have some very sophisticated clearance ramps, though the valve clearances - at a mere .002inch and .003-inch, for the intake and exhaust valves respectively - are tight enough to prevent much possibility of clatter. There is an advantage with overhead camshaft valve actuation at least as important, in present-day context, as its benefits in terms of high-revving horsepower.
Cruising at 65 to 70 mph you don't hear anything over the roar of the wind around your helmet but an occasional jingle from the drive chain (reminding you that it needs oiling every 500 miles). There is a high-frequency vibration that begins to blur images in the rear view mirror at exactly 60 mph, indicated. You might wish for this to be gone, just to clear up the view in the Honda's mirror. It isn't obtrusive enough to be worrisome, and it gives us something to anticipate beyond the CB-500: four-cylinder, in-line engines have perfect primary balance, but leave the secondary shaking forces - which are generated at twice crankshaft speed, in the plane of the cylinders' axis -uncompensated. Maybe someday Honda will add small counterweights, driven at twice engine speed, to smooth out even this last external manifestation of reciprocating action. Much the same thing could be accomplished with a little rubber bushing in each engine mounting - which would make the CB-500 absolutely turbine smooth and leave us with one less picayune item for complaint.
To continue with the picayune, we'll say that we think the CB-500 is wonderfully comfortable to ride for long distances, where comfort counts, except for two things. First, the kick-start lever's folded position isn't folded enough: it digs into your right calf unless you slide your foot back on the peg and take a grip with your toes. When you fire up the torch to curl your CB-500's side and centerstands closer to the pipes for cornering clearances hit the kick-start lever a lick unless you can't bear the thought of scorching the chrome. Better yet, take the lever off and leave it hanging on a garage rafter.
The other long-ride discomfort is one which is easily removed if you are given to overkill. Here's the problem: Honda has put a throttle-return spring on the CB-500 that fights you for every inch of throttle movement. Holding the throttles open is a strain; winding them up and down as you swoop through the mountains will put a genuine Charles Horse in your arm, in no small part because the stiff return spring's resistance is combined with a slow throttle action. You have to crank the CB-500's throttle open like a faucet, and it turns too far to be comfortably managed with wrist action alone. The technique is to reach around the twist-grip until your wrist joints hit their stops before grabbing the throttled and then crank your wrist clear back to the opposite end of its travel. After you've stretched the tendons a bit the throttles may wind completely open with the first handful. The process is helped along by doing what We did, which was to disconnect the throttle-return spring and replace it with a longer, softer one. Honda's CB-500 has a pull-open/pull-close throttle mechanism, so you can dispense with the spring if you feel like chancing the consequences of a broken closing cable.
Braking? Honda's CB-500 has the disc front brake we have come to expect on the better motorcycles, and it works as expected. There is the typical disc brake's tendency to squeal with light braking, with the typically linear relationship between pressure at the lever and retarding force at the wheel. Good control, and tremendous, tire-howling braking - up front. The rear brake is a drum, and not an awfully impressive example of the type. It is far too sensitive, with a habit of locking under light pedal pressure, and this is only partially compensated by the fading that occurs quickly with hard use. it's more an aggravation than a danger: in a really hard stop the extremely powerful front brake's action transfers most of the weight off the bike's rear wheel.
Fuel economy probably doesn't mean much in do1lars to the man who has enough of them to buy himself a four-cylinder Honda. But this factor does become important when it is translated into cruising range. On average, the CB-500 goes 110 miles before the tank has to be switched to reserve, using 2.7 gallons and giving about 41 mpg, which means that the bike will go just over 150 miles on its total 3.7 gallons of fuel before it runs completely dry. We should note here that the 41 mpg mileage figure given is our test average. Riding with the throttles retracted a bit less than is our wont stretches the mileage to about 50 mpg and that number probably more accurately reflects what the average, non-maniacal CB-500 owner can expect.
The most surprising, and revealing, thing we can tell you about Honda's CB500 is that it takes some getting used to - for a variety of reasons. The rear brake is an obvious case-in-point, and there's no need to elaborate on its failings more than we have. You'll also have to get accustomed to an engine that just hasn't any flywheel effect worth mentioning. Without a load, the engine will shoot from idle right to its redline in a blink, and drop back to idle just as fast. This combines with the shifting notchiness to produce a 1ot of lurching when gear changes are made until you become really practiced at coordinating throttle, clutch and gear pedal. The same lack of flywheel and extreme willingness to spin could get you in trouble with overshooting the redline, but there isn't much excuse for that as the power curve feels substantially flat all the way from 6,000 rpm to 9,300 and you can use the excellent gear ratios to stay comfortably below the danger mark. The bike's handling isn't as quick as its ability to churn up engine speed, but it is quick enough to allow you entertaining games.
Put all these things together and you have history's pluperfect, triple-distilled and classic 500-class motorcycle. It takes a bit of skill from its rider before giving its best. Yet. behind the bike's almost nervous responses there is a willingness to rescue you from any really serious errors you may make. You can force the CB-500 to pitch you into a hedge; it won't help the process along with a fit of wobbling. You can overlook that red pie-slice on the tach, and the engine will overlook your lack of attention to its best long-term interests.
That's the kind of thing the traditional rider of 500s likes. That's the Honda CB500.