Honda CBX 400F
Honda CBX 400F
Air cooled, four stroke, transverse four cylinder. DOHC,
4 valve per cylinder
Bore x Stroke
55 x 42 mm
4x 26mm Keihin
CDI / electric
48 hp @ 10500 rpm
6 Speed / chain
35mm Kayaba forks, 138mm wheel travel.
Single air shock, 103mm wheel travel
Single 229mm disc
Single 229mm disc
13.5 sec / 155 km/h
It's not easy to follow in the footsteps of a legend.
Not even a junior-grade motorcycle legend like Honda's CB400F. Its half-life on
this planet was so brief that its biography is but a short paragraph in the
magnum opus of moto-history, yet it still managed to earn cultbike status
amongst the cafe-crazies. Many of them even vowed never to forgive Honda—not
only for terminating a magnificent motorcycle after just three short
model years (1975 through 1977), but for having the gall to think that the CB400
Hawk, a twin-cylinder econobike, would be a suitable replacement.
Well, listen up, all you fans of the late, great CB400F: The
400 Four is back. No, it's not the same CB400F you've grown to know and love,
it's a substantially better one—better in power, in handling, in braking, in
comfort and in just about any
other way you can imagine ... except for availability. The catch, you see, is
that this bike, called the CBX400F, is sold only in Japan. And American Honda
professes to have no intention whatsoever of bringing it into this country. Not
now, not ever. And for the same reasons that sent the original CB400F down the
tubes: It's so costly to manufacture that it can't be competitively priced, and
the target audience is felt to be too small to satisfy Honda's minimum
That's probably okay with you, though, since most riders
didn't lament the passing of the old 400 Four any more than they do the new
one's failure to reach these shores. They are, after all, only 400s, which
equates to buzzy, twitchy, cramped, slow, little motorcycles, the kinds of bikes
in which you have absolutely no interest. But before you turn a deaf ear, hear
The CBX400F is none of those things. We know; we spent an
entire month testing one that had been imported by DG Performance Accessories of
Anaheim, California. And we're talking about a mid-13-second motorcycle here,
folks, a bike that'll blow not only the old CB400F into the weeds, but a lot of
bigger and more highly exalted machinery as well. We're talking about a bike
that weighs just 402 pounds and has a low, 30.7-inch seat but that doesn't feel
at all undersized; a motorcycle that will dart off into a fast corner at the
very thought of turning, yet is as stable on the open road as something twice
its size. We're talking about an honest-to-God, for-real motorcycle that just
might, if you could get your hands on one, make you forget that the original 400
Four ever existed.
Your first indication of the CBX400F's for-realness can be
found on the tachometer face, where the engine redline is set at an unbelievable
11,500 rpm. Jeezus. Nothing but purebred racing machinery has ever had a redline
that high, especially a four-stroke. But Honda has struck the mother lode of rpm
on this bike without resorting to anything but its tried-and-proven
short-stroke, four-valves-per-cylinder technology. The sizable bore of the
highly oversquare engine (55mm bore and 42mm stroke, as opposed to the 51mm by
50mm dimensions of the CB400F) provides the large valve area needed for a high
power output, while the extremely small and light valves in each 99.8cc cylinder
permit ultra-high rpm. And the short stroke yields the low piston speeds
necessary to prevent the engine from ripping itself apart
Indeed, but your mental tachometer just isn't calibrated to
deal with 11500 rpm, so you'd never know that the engine wasn't self-destructing
by the way it sounds at those speeds. The CBX400F wails like a runaway air-raid
siren as the engine approaches redline, and the shrieking resonates inside your
helmet so loudly that it's all you can hear. The intake roar alone is menacing
enough, as though you and the seat are about to be sucked into the 26mm Keihin
CV carbs at any second. And you can't help but feel that something—a piston, a
rod, perhaps one of the 16 valves that is being hammered open almost 100 times a
second—is going to come flying up and eunuchize you on the spot.
Of course, this all sounds more apocalyptic than it really
is, since the CBX400F is perfectly happy to run all day in these absurd rpm
ranges. What is surprising though, is that despite the engine's high rpm
inclinations, it's not at all peaky.
The best performance, obviously, comes in the upper part of
the powerband, say, between 7500 rpm and redline. And to that end, the
slick-shifting six-speed gearbox has very closely spaced ratios that keep the
revs from dipping below nine grand (except between first and second, where they
drop from 11,500 to about 8000) during a WFO run. Nonetheless, the power
delivery is almost linear from idle to redline, with only a slight increase in
acceleration in the upper third of the rpm range.
Some of the CBX400F's reasonable mid-range stems from the
exhaust system, which pairs off the cylinders that fire at even, 360-degree
intervals (Nos. 1 and 4 lead—^ into the left muffler, Nos. 2 and 3 into the
right). The conventional arrangement (feeding Nos. 1 and 2 into the left
mufflejtf^ and Nos. 3 and 4 into the right) is cos- -metically more symmetrical
but not as efficient, since it adjoins cylinders that fire at uneven
This is not to imply that the CBX400F's midrange performance
is in the literbike league; it's not. There's usable power on tap at virtually
all rpm in all gears, probably even more so than on the old 400F. But when
you're at cruising rpm and want to summon some serious acceleration, a downshift
or three usually is in order.
If that's the trade-off for having a 400 that performs with the excitement of
this one, it's a small price to pay. Honda claims a whopping 48 horsepower at
11,000 rpm for this engine, which is more than 10 horses and 1500 rpm higher
than on the CB400F. But since the new bike's 13.588 quarter-mile time is 1.2
seconds quicker than the old one's, we have no reason to doubt that claim.
Those dragstrip numbers also mean that the CBX400F will
outrun a slew of 500-550cc motorcycles and all of the 400-450cc four-stroke
twins. And any stock RD400 Yamaha that sees a CBX400F coming had better run the
other way if it hopes to avoid being embarrassed. Not that this racy,
rpm-aplenty double-hammer doesn't have its practical side. For one, it's the
first four-valve-per-cylinder fconda multi to abandon shim-type cam followers in
favor of the forked, screw-adjustable type (a la Suzuki GS750E/ 1100E) that
makes valve-lash adjustment easy and inexpensive. And everything else inside the
engine is conventional fare, from the plain-bearing crankshaft to the Hy-Vo-type
cam chain and primary chain to the solid-state breakerless ignition. The CBX400F
engine might perform like a racer out on the road, but it's just another motor
in the shop.
The same can be said about the chassis, which has a
distinctly racy personality when in motion but is comprised mostly of ideas that
have seen service on other Honda models. The front fork is air-assisted, as is
the single rear shock that is Pro-Linked to an absolutely gorgeous cast-aluminum
There are no provisions for making damping adjustments at
either end—perhaps a concession to the inordinate high cost of a 400cc four but
you will find one of Honda's TRAC anti-dive mechanisms on the left fork-slider
leg. The steering geometry on the double-down-tube frame is a touch slower than
the old 400F's (97mm of trail compared with 84mm), and the wheelbase is about an
inch longer. Both tires are H-rated 18-inchers mounted on attractive ComStar
wheels. See? Nothing revolutionary about that.
But due to the CBX400F's light weight and well-balanced
chassis design, all of its handling magic is found in the riding, not on the
spec sheet. The bike is so inherently stable that you don't have to concentrate
on keeping it going straight when you're not turning, yet it practically begs to
be tossed into a hard turn. It banks over with remarkable ease, even when
braking hard, and it willingly follows whichever line you choose. You can even
change lines in mid-corner if you so desire—partly because the steering remains
so neutral when the horizon is tilted over at crazy angles, and partly because
there's so much cornering clearance that you can usually tighten up your arc if
need be. You have to lean this machine way, way over before the centerstand feet
(and, on the right, the footpeg) contact the ground. Even with no air at all in
the suspension units (not, incidentally, a recommended procedure), it takes a
fairly aggressive charge through a corner (or a sizable bump therein) before
hardware kisses highway.
Overall, the CBX400F handles corners of all sizes, shapes and
speeds with aplomb, never wiggling or twitching in the least. But the bike has
its finest hour in the tight twisties, where the quick steering and high-rev- s
ving engine rocket it from i turn to turn about as fast as g most riders care to
go. If you | don't come away from an £ llVfe-grand charge through * the hairpins
on a CBX400F feeling like a card-carrying roadracer, chances are you never will.
Still, given its propensity for back-road blitzing, the Honda
is quite comfortable in cruise mode. The engine is pleasantly smooth below 6000
rpm and acceptably so above it, and the ride quality most of the time is just
short of plush. Only certain small, abrupt bumps deliver any harshness to the
rider, and even some of those jolts would prove less annoying if the seat were
more comfortable. It's rather firm and ill-fitted to the nether regions,
rendering it a not particularly luxurious place to park for more than an hour or
It's tempting to dismiss the seat's problems as merely the result of the bike
being tailored for a 5-foot 5,130-pound Japanese and not for the average
(five-ten, 170 pounds) American; but there's nothing elsewhere in the ergonomics
to back that supposition.
The riding position offers a near-perfect Euro-style
sportbike tri-angulation, even for six-footers, and the spacing between the
rearset pegs and the foot controls seems spot-on for Amercian (read: big) feet.
And a large rider can even see what he's left behind, since the mirrors are
spaced fairly far apart, despite being mounted on narrowish, cast-aluminum
A rider of any size, though, can appreciate the most innovative feature on the
entire machine: the brakes. Fundamentally, they're conventional ventilated-rotor
hydraulic disc brakes, one per wheel, the difference being that each disc is
enclosed within a housing reminiscent of a drum-brake hub.
The claimed advantages are: 1) The disc is protected from
water and grime
that could adversely affect braking; 2) the disc attaches to the hub around its
outside diameter rather than around the inside, thereby dissipating heat more
efficiently into the large, finned hub and not through the wheel-bearing area;
and 3) attaching the disc around the outside allows both disc and caliper to be
located closer to the cen-terline of the wheel so that their weight is more
evenly distributed on the axle.
Unfortunately, it never rained during our test of the
CBX400F, so we can't report
on the bike's wet-weather braking competence. But we can tell you that in the
dry^jk the brakes are superb. They're always won" Jf derfully progressive,
sufficiently powerful and resistant to fade even when deliber4|J ately abused.
Assisted by the TRAC-which, on this bike, works far better than any anti-dive on
any motorcycle we've ever tested-the CBX400F's stoppability is above reproach.
The brakes are eye-catchers, as well, with generous finning
on the hubs and calipers that gives them a high-tech, exotic ook. It's all part
of a concerted effort by onda to style the CBX400F as a serious enthusiast's
motorcycle, not as an entry-evel tiddler. It certainly works, to our eyes, at
least. And the best styling lick of all is the rear turnsignals, which are
cleverly integrated into the outer ends of the taillight lens. But since that
places the signal lights too close together to comply with U.S. regulations,
don't look for similar treatments on Hondas sold here.
That's too bad. The real pity, though, is that the entire
bike, or anything like it, won't be sold here. It's our loss, since the
CBX-model 400F is an exciting, competent, complete motorcycle, one whose only
faults are its seat, its lack of small-bump suspension compliance and its mild
shortage of rebound damping in the rear shock-all of which undoubtedly would be
rectified once the bike were recalibrated for American roads and riders.
Honda says that won't happen, but maybe it's time for all of us to reassess
bikes like this one. Times do change, and the cli-
mate for a 400cc, four-stroke, four-cylinder pure sportbike could be
considerably healthier now than it was five years ago.
The CB400F got lost in the shuffle back then amidst
everyone's mad rush for 11-sec-ond performance and hot-rod literbikes, but the
pendulum has begun to swing the other way. The trend now is more toward mid-size
motorcycles, and the CBX400F more than qualifies as one of those. Modern
technology allows it to perform like a 550 and, in fact, almost as well as a
CB750 Honda of the '75-'77 era. Besides, what endeared the original CB400F to
its followers was its appearance more than its performance, for it was the first
Japanese motorcycle that didn't look like one. But beneath its European-inspired
cafe-racer exterior was little more than an overbored 1974 CB350 Four—certainly
not one of history's most memorable motorcycles.
But you have our guarantee that, given the chance, you would remember the
CBX400F. And not just for its styling, either. It's one bike capable of
performing like a legend as well as looking like one. •
• Okay, the CBX400F is unobtanium, but this isn't going to be
another dissertation on how the motorcycles are always better on the other side
of The Pond. That's almost incidental. But central to the 400F's attraction is
that you can wring the be-jeezus out of the thing—going really fast in the
bargain—and get off feeling that you've used every ounce of performance that the
littlest CBX has to offer.
All that might not mean very much if the CBX were "just
another 400." But it isn't. From the inboard discs to 16 of the tiniest valves
you've ever seen, the CBX fairly sweats performance. And it all works. So you
can view the CBX as just another interesting piece of hardware that's not
available in stores if you want to. Not me. I figure that it's rolling proof
that performance 400s—a class almost forgotten of late—still provide their own
special joys. —Larry Works
• As a former owner of Honda 305 and 350cc twins, I've got a
soft spot for small bikes. My roots run deeper, too, having spent most of my
roadrace days aboard Yamaha RD350s and 400s. So riding the CBX400 was like
meeting an old friend.
While, the engine's broad powerband helped pump my adrenaline quicker, it was
the chassis and brakes that made me rediscover sub-500cc riding. Specifically,
the front disc and anti-dive fork retapped my small-bike energy, and most of my
CBX-fun was doing Eye-Openers: slamming into corners with a handful of brake.
It's a game that's especially fun on the CBX400 because there's no transition
period while waiting for the suspension to settle before apex-aiming. And as any
small-bike enthusiast will testify, that's the thrill of sub-500 riding.
• After my first ride on the CBX400F, I was not overwhelmed.
Oh, it seemed to be a nice enough motorcycle, but it didn't feel nearly as fast
nor as nimble as my much-modified '75 400 Super Sport.
But then I went out on my 400F, and the rosy memories turned sour. The CBX400F
is more competent in almost every way than mine ever thought about being. The
new 400F revs quicker, turns with less effort, and has a better seating position
and more power. The only thing I preferred on mine were the brakes, which have
more feel, but at the expense of requiring more effort.
There is one thing they have in common, though: Both 400s make willing
accomplices for the sporting rider, allowing him to learn and improve his craft
without scaring himself. Now, if Honda would only bring it here ....
Source Cycle Guide 1982