Honda Fob. 1978
HONDA FOB. 1978
Behind Closed Doors: Honda’s R&D Was Not Sleeping If Anything, the Rumors Were Understatements
hen you have a product line-up
'as comprehensive as that of the
Honda Motor Company. two in-
troductions per year would make sense whether you had any secret stuff or not. But of course, Honda always has some secret stuff brewing.
We’d heard plenty of tantalizing rumors—Vee-Twins, Vee-Fours, Vee-Sixes, 1400cc shafties, a violently potent new motocrosser—by the time we put our November issue to bed. But at that point they were only rumors, and the 1978 Honda preview sandwiched between the covers of the November 1977 CYCLE WORLD contained only the bikes that were known quantities. The 400cc Hawks had been introduced a few months earlier, and thus the star of the official 1978 preview was the updated GL1000.
Yawn.
Honda’s security is pretty damn tight. Aside from the CR250R motocrosser, tested last month, until Honda staged its second ’78 preview, none of us had even seen any of the bikes you're seeing on these pages. We’d seen artists’ drawings, w'e knew a good many of the particulars, but we’d never gotten a look at even one of them in person.
So welcome to Honda's 1978 Preview, Part II. This time they dragged out all the secret stuff, thus blasting some of the rumors and confirming others. Another tribute to internal security, in a way.
No Vee-Fours or Vee-Sixes, but a By God inline Six and a w'atercooled VeeTwin shaftie that’s got to be hands-down winner of Best Engine Design of the Year. As noted, we met the motocrosser last month, finding it the best machine of its kind we’ve seen to date. (And inasmuch as it’s been just a month since w'e tested the CR250R, we note it here only in passing with a picture and specifications.)
There’s also an impressive completely new' approach to the trusty and w’ell-loved XL250 dual-purpose bike. And for good, clean, mindless fun around the campground, Honda has revived its old threewheeled all-terrain trike.
Although the new Hawks w'ere hatched amidst great acclaim, Honda w'as hardly what you’d call a dominating presence in the 1977 motorcycle market. With the introduction of the lightweight Hawk line, we saw' a hint of things to come . . . followed by a power vacuum. The swashbuckling creativity and relentlessly innovative spirit that has characterized so much of Honda’s product planning seemed dormant.
CYCLE WORLD Photos
But only dormant. More accurately, poised and waiting, with an arsenal of new weapons to blow the doors off the competition. There are plenty of other individual stars in the 1978 Motorcycle Revue. But Honda may just steal the show'.
HONDA CBX
In a year of Mightybikes. this one stands to be the hairiest of them all. Even if it was a boat anchor, it would get high marks for sheer chutzpah. But on the other hand— with all due respect to Benelli—what could be more reasonable than a transversemounted inline Six? And this missile figures to make good on its manufacturer’s basic aim, to wit: the creation of the fastest, best-handling superbike going. With 103 bhp locked up in the 1047cc dohc 24valve engine, the fastest part seems well within reach. And even though we’re thoroughly impressed with the handling qualities of the Suzuki GS 1000 tested elsewhere in this issue, the CBX’s cornering clearance makes it look like a solid contender in the nimble department.
By removing the alternator from one end of the crankshaft and the ignition (pointless inductive, firing three coils lurking under the 5.3-gal. gas tank) from the other end, Honda has contrived to keep this scorcher much narrower than one might expect, only 20mm wider than the 750, according to the manufacturer, and 40mm narrower at the footpegs. (These, incidentally, are of forged aluminum at the rear, as are the gearshift lever and brake pedal. Nice.)
It’s going to be fun rummaging around inside this engine. The six 28mm CV carbs, boosted by a common accelerator pump on carb number three, are mounted on a Vee-shaped plate with their intakes inclined toward the center of the bike about 8 deg. The 350-w'att automotive-type alternator is intended to put out enough charge to cover for the absence of a kickstarter, and the alternator is friction driven off the primary shaft. This reduces strain on the shaft and can be worth up to a halfhorsepower in certain rpm ranges. It’s a touch that’s significant if only as an indication of the thoroughness of Honda design teams.
The camchain setup—employing Hy-Vo type chains—is also ingenious. The exhaust cam is run off a chain that climbs out of the engine's bottom basement, and the intake cam chain is driven off the exhaust cam. There's a double trochoidal wet sump oil pump to keep everything slippery, and an oil cooler to keep the slippery stuff from overcooking. The oil cooler also kept heat dissipation from being a particularly critical consideration in exhaust design.
We asked a project engineer how he and his colleagues happened to arrive at the 1047cc displacement. “We started with lOOOcc and decided we wanted more guts,” he said, “so we wound up going up another 50cc.” Looks like they got it. The 103 bhp (at 9000 rpm) represents a mild state of tune for the CBX, according to Honda. The engineers calculate another 17 horsepower or so can be coaxed out without a trip to the machine shop, and that a total of 130 might be obtainable with some headwork. But beckoning more horse-
power out of this torpedo qualifies as the most gross sort of overkill. As is, it's expected to produce quarter-mile times in the region of 11.5 or 11.6 sec. with the top end somewhere around 140 mph.
The Six resides inside Honda's diamond configuration frame, which eliminates the downtubes of a conventional double cradle without sacrificing anything in the way of added flex, according to the engineers. There are Honda’s two-stage shocks, similar to those introduced on the Hawks, at the rear, and Showa forks with dacron slider bushings up front. The wheels on the CBX and the CX500 are Honda’s patented ComStars, and they're fitted with tubeless tires, an industry first, designed for high speed use. The tires will be supplied by Yokohama and Bridgestone. Brakes are triple disc, two front, one rear.
The handlebars are forged aluminum and the headlamp is a quartz-halogen unit, another basic equipment item the CBX shares with the CX500.
Instrumentation is attractively laid out and we expect it to be up to Honda's usual
high standards. There’s a fork ignition lock combo, a handy item that we missed in the Hawks, and a particularly intriguing touch is the fuse box. mounted amidship atop the bars. It’s handy and secure—the top stays down with four screws.
Styling? Once you’re able to stop counting the headpipes, and consider this thing as a cosmetic entity, you’ve got to agree that everything about it says Superbike. And it’s just possible that this machine may represent the zenith of its class, at least in terms of streetable moxie. We have no reading on the price at this writing, but expect it to be in excess of $3500. We also expect to have our hands on a CBX in time for a test in our April issue, so don’t hang up. The bike will probably appear in show -rooms sometime around mid-April.
CX500
Now' that we’ve suggested the Six as a candidate for all-everything, let us hedge our bet by presenting the most ingenious engine design to come along in many years. Honda’s design goal here was the development of a mid-range combination touring/sports bike that would also be the most distinctive piece in its class. The engineers have outdone themselves. This liquid-cooled 496cc 80-deg. pushrod VeeTwin is likely to be the most distinctive powerplant on the road this year. The heads are rotated 22 deg. from a conventional configuration, which allows the two 35mm CV carburetors to be tucked into the center of the bike, and there are four valves per cylinder. One rocker arm operates two valves, and these are actuated by no-nonsense 11mm stainless steel alloy pushrods. Honda says there isn’t a micron of flex in these, even at peak rpm ( 10,000). Peak horsepower—50—sets in about 1000 rpm earlier than top revs.
The Twin’s cooling fan is mounted on the camshaft end at the front of the engine. On the other end, a cast iron impeller stirs coolant around inside the engine. It’s a simple system that saves weight.
Inside the Twin's crankcase, which is a one-piece casting, the connecting rods share a common pin (43mm) on the cutfrom-the-living-rock crankshaft. A chaindriven trochoidal oil pump sends lubricant into all the engine’s snug places, and there’s an adjustment for the chain.
The massive multi-plate wet clutch is gear-driven directly oft'the crankshaft and turns in the opposite direction. This reduces the torque reaction of the shaft drive Vee. Power is sent through a 5-speed constant mesh transmission into the shaftdrive system. The shaft runs inside the right side of the swing arm and into the, ring and pinion at the rear. The entire shaft drive unit is smaller than that on the GL1000, and the Honda engineering people also regard it as an improvement on the Gold Wing setup. One indication of the general quality is that the rear end needs no gaskets; the surfaces mate so well gaskets are superfluous.
The flywheel-driven alternator is rated at 170 watts, and, like the CBX setup, is intended to keep the battery good and zappy to be sure you won’t have to resort to the kickstarter. because there isn't a kickstarter.
Exhaust is 2-into-2. with a power chamber grafted between the pipes about halfway back. Honda says this item allows the use of shorter, megaphone-style mufflers that are nicer to look at. They also produce a satisfying exhaust note. Honda says further that the power chamber increases mid-range horsepower by as much as 4 bhp.
The diamond frame has been employed on this machine, too. operating in league with Honda’s two-stage rear shocks and three-stage spring rates of the front fork. This suggests impressive handling. The forks are equipped with the low-stick (and expensive) dacron bushings found in the CBX fork. Honda’s centerization of mass design credo is particularly visible in this bike, promising to make the sports part of the design objective a reality.
ComStar wheels, again with tubeless tires, are employed fore and aft, and the brake system is a front disc/rear drum combination.
The CX500’s instrumentation is similar to that employed by the CBX, with the addition of a coolant temperature gauge. The fuse box is mounted atop the bars, and the tank rides atop 3mm of urethane padding for sound deadening. We expect the mini-GL to he even more mechanically quiet than its big brother.
One other thoughtful touch on behalf of future CX riders is the bike's airflow characteristics. Hot air from the radiator is routed out around the heads instead of over the rider’s legs.
This machine seems almost certain to appeal to tourers who like the various advantages of the Gold Wing—shaft drive, low maintenance, etc. but are put off by the GL's size (626 lb. for our most recent test, last August). The CX weighs in under 450 lb. dry, according to Honda, w hich is a much more manageable package. This helps to make it reasonably quick, as well. Honda projects it as a sub-14-sec. machine. and possible the fastest in its class. Combine quickness w ith w hat promises to be excellent handling and a fascinating new powerplant and you have a bike that might just be the best of the half-liter field.
$1898
XL250S
If it demonstrates nothing else, the new XL250S indicates this much: Honda is listening. What’s been one of the most common complaints against the old XL250? Weight. With a half-tank of fuel the last one we tested (August. 1976) scaled in at 312 lb. The new edition is going to come in about 40 lb. under that total. How about oomph? We didn't get a factory horsepower rating on our '76 XL. but the new one’s 20 blip is definitely going to be an improvement, particularly in league with this slimmer edition of the bike. Vibration, another constant lament of thumper riders, is certain to be much reduced in the new incarnation, which features counter-rotating balance weights as part of its inventory of internal goodies. One of these is shaft mounted above and ahead of the crankshaft, chain-driven off the left side of' the engine. The other is mounted on the mainshaft, thus saving the weight of another shaft, as well as an extra drive chain. The engine a 248cc sohc 4valve Single has an extra exhaust headpipe. allowing the engineers ( 1 ) more latitude in engine location and (2) the use of a smaller, lighter muffler. The latter weighs 8 lb. There’s an air passage between the twin exhaust pipes, making for better cooling.
The other neat touch is an automatic compression release, a neat bit of engineering sleight of hand that holds one of the exhaust valves open through about the first third of each kick. The release is cablelinked to the kickstarter; an actuating arm presses the exhaust valve open.
Honda has been busy with the chassis and suspension, too. The old single downtube frame has been replaced by yet another diamond frame. Ground clearance has been raised from 8.75 in. to 10. seat height has been reduced a half-inch, the leading-axle front fork has 8 in. of travel. 1.25 in. more than the old unit, and travel on the lay-down gas shocks at the rear is 7.9 in.. 2.9 in. better than the old XL.
Honda laid its chassis design down around a 23-in. front wheel, figuring this is a wheel that w ill climb over anything, and you may see the same wheel on future motocrossers.
Instrumentation is improved, with big, easily legible numbers on the odometer, which is equipped with a big reset knob that looks to be easily adjustable even w ith gloved hands. The turn signals are mounted in rubber, to help them survive minor falls, and the grips have sealer lips that should help keep mud and water from becoming a nuisance inside awkward places like the throttle spool.
Brakes are drum at both ends, and the conical front hub looks very much like the one we encountered on the CR250R motocrosser. The tires, sporting a new tread pattern that Honda thinks really will serve both dirt and street riding, are mounted on DID rims.
Honda sees this machine as the cream of its class, as well as where the market must inevitably go (four-stroke, that is), and it certainly seems likely to be better in either dirt or street riding than any 250cc dualpurpose bike that’s preceded it. We were unable to obtain even a ballpark price on the bike, which will appear in showrooms sometime in mid-April, but expect it to be under $1300. since its direct competitor, the Kawasaki KL250. is a hair under $1200.
ATC 70
Here’s a machine that anyone in the family can play on without much risk of crash-and-burn. The 72cc sohc Single won't be very satisfying to the fire burnout set, but it will haul this little trike over almost any kind of sand, gravel, dirt or even snow on its fat. low-pressure knobbies. The driveline is completely enclosed for safety, there are oversize footpegs and an easy-shifting 3-speed constant mesh transmission with automatic clutch.
It’s easy to drive for almost anyone, and the spark arrester insures that you can drive it virtually anywhere you go. g>]
