Two Wheels Road Test

HONDA CBX PROLINK

A TAMER TITAN

Mega bike enthusiasts reacted differently, however. All marvelled at the super-technology
built into the CBX, the world's fastest readily procurable motorcycle and, along with
the Benelli Sei, one of very few bikes to boast six exhaust headers. All marvelled at its
fearsome accelerative capabilities and the stunning appearance of the huge, across-the-frame
power plant. The jet-like exhaust shriek of a CBX doing its thing no doubt sealed a few more
sales for Honda among those sufficiently well-heeled to shell out the $4300 asking price for the blatant Six. 

While all this marvelling and drooling was going on in Motor Show frontlines and elsewhere, a few
wise voices will back in the throngs asked pertinent questions like does it handle, does it stop
and how much will keeping it tuned cost? The answers to these questions left something to be desired
and TWO WHEELS was among the first publications to say so. We liked the CBX's awesome straight-line
performance but found handling and braking decidedly below par on both bikes we rode. Two other CBX's
we've spent time on since our February 1979 road test did little change our opinion, which was further
vindicated when most Honda prod racers chose to campaign 900 Bol D'Ors. Act one ends with only a handful
of sales each month.

Act two opens with Honda quietly releasing the CBX-B a Pro-Link suspension equipped, touring
rethink of the original six-cylinder concept. The CBX becomes the most expensive Japanese bike again,
selling for $4876, about $300 more than Kawasaki's 1300 water bottle. But don't expect the Mark Two Honda
Six to be anything like its predecessor - it's more like the diametric opposite. And TWO WHEELS is only too
happy to finally be able to give Honda's flagship the "thumbs up".

The Bike

Let's be blunt from the outset. The CBX has lost its sting. If tarmac-wrinkling acceleration
is for you, forget the 24-valve six - there are any number of one-litre fours able to outgun the CBX-B,
surprisingly Honda's own 900 sportster among them. Of course, no modern motorcycle displacing a litre or more is slow - the detuned Six will still put
a true 160 km/h on the Speedo 9.3 seconds from rest. But the GSX1100 and GPz1100 king-hit fours will pull
the old ton in eight seconds or less and shave 0.4 seconds off the CBX-B's 4.4 seconds 0-100-km/h time.
The Six's 12.2 second standing 400 m time with the best of tyres aboard puts it at the tail end of mega bike
performance. Kawasaki's delicate Z750 (by comparison) can chew the quarter in 12.4 seconds. Oddly, the one
Japanese heavyweight that does give CBX-B-like acceleration times is Suzuki's weighty but delightful GS1000G
shaft drive tourer. In many ways these two bikes are similar and the adjectives "weighty but delightful"
are as apt for the new CBX as they were for Suzuki's sweet riding four. The real ugly-ducking-to-graceful-swan transformation occurred in the two primary safety areas -
handling and braking. Gone is the weaving and general instability that beset our old test CBX's so
badly every time the rider used some of the performance in anything but a straight line. Steering
and handling on the original CBX were fine
up to 110 km/h; from there upwards they degenerated so rapidly and bend swinging on the high side of 130 km/h was heart-in-the-mouth stuff. How Mike Cole ever piloted such a monster in production races we can't imagine. The CBX-B, on the other hand, mimics the 900 Bol D'Ors behaviour and simply keeps getting better as speed rises. Indeed, so stable is the new Six at 160 km/h plus speeds that we are prepared to call it the most stable bike ever for really fast riding. Ducats, Jotas etc. notwithstanding. Honda has made a host of chassis alterations to bring about this change in handling. Starting at the front, the new CBX has its forks raked out a full two degrees more than last year's model, to 29.5 degrees (to improve high speed stability), but trail has been kept at 120 mm by designing special triple clamps which also space the forks 10 mm further apart. The forks themselves received a massive injection of rigidity when their original, rather slender diameter of 35mm was bumped up to 39 mm for the B revision. Fork response remains excellent, aided by Honda's low-friction Syntallic bushings and the air assistance (added for the 1980 CBX). A pair of triple-rate coil springs govern the forks' basic reactions while a seven to 13 psi recommended range for air pressures fine-tunes front-end ride. The wheelbase on our test bike measured a long 1550mm (up 50mm) due to the increased rake and longer Pro-Link rear swing arm. Made up of welded, box-section aluminium, the new swing arm rides on needle and ball bearings to ensure that flex is eliminated. Rear suspension is controlled by a link operated monoshock system derived from Honda's motocrosses. The set-up is named "Pro-Link" suspension because the ratio of axle travel to shock compression rises progressively; from 2.78:a when the rear suspension is fully extended, to 1.92:1 if the suspension bottoms out. This leverage-induced stiffening of the rear suspension is multiplied by the use of air rather than a coil spring as the main compressive medium. A steel spring gives a near constant compression change for each load increment, hence the120lbs/inch-type compression rating of springs, but the reaction of air in a closed cylinder when its volume is compressed by a piston is progressive - the higher the initial compression, the greater the force necessary to further compress the air. So the CBX-B has a two-way stiffening of its rear suspension with compression. The Pro-Link unit itself does incorporate a lightly wound coil spring, but its main function is to prevent total suspension collapse in the event of an air leak. When air pressure drops in the rear suspension, an idiot light on the dash warns riders and the manual advises a maximum speed of 80km/h. Damping is three-way adjustable via a knob below the right side cover.