1980 Honda CBX Road Test - page 4

Internally, the well-oversquare CBX engine is unchanged except for its different camshafts. Bore and stroke remain the same at 64.5mm and 53.4mm respectively, and each piston carries three rings; two compression and a single oil control ring. Steel connecting rods bolt together around the one-piece crankshaft's big-end journals, while seven plain main bearings support the crankshaft.

To keep the CBX's crankcase width down to 23.4 inches (the XS11's engine is 23.0 inches wide), the Honda's outer crank flywheels are beveled - and narrower than their interior counterparts. And the bottom of the CBX's engine cases - at their outer flanks - are 1.3 inches higher than the Yamaha's. You may graze footpegs, nick the side- and centerstands, but you will not ground the engine.

Centrally located between the crank flywheels for the number three and four cylinders are two Hy-Vo-type chains; the first is an automatically tensioned unit that attaches the crankshaft to the clutch-drive jackshaft. A second longer, slimmer Hy-Vo-type runs up to the rear camshaft, pulling it in the same relative direction as the crank. Another chain runs from the intake to the exhaust cam, minimizing overall chain stretch and flopping that would occur by using a single long chain.

Both the intake and exhaust cams are actually two-piece affairs, linked together at their inboard ends by steel Oldham couplers. The shafts ride in the head material - no inserted bearings are employed - and the CBX camshaft clearance-adjustment shims ride on top of inverted cam follower buckets. In this manner, the camshaft lobes push on the replaceable shims, the shims on lifter buckets and the buckets on the valve stems themselves. Clearance adjustments require each valve be held down while its shim is nudged out and a new appropriately thick shim replaced.

The crankcase-housed clutch jackshaft drives both an automotive-type A.C. generator and a triple pickup ignition distributor rotor, and provides an engagement gear for the Honda's starter motor. A clutch housing-pulled chain and sprocket turn a trochoidal oil pump, which sends oil throughout the engine and transmission.

Eight drive and seven driven plates make up the wet clutch-which uses the same oil as the rest of the engine. Oil capacity is 5.5 liters, including that held in a frame-mounted radiator that is 20 per cent larger on the 1980 CBX. Interestingly, despite the additional oil-cooling capability, our test bike's clutch burned up during its fourteenth dragstrip run, and after replacement, the new one became grabby, and draggy while disengaged. Before its initial demise, the clutch handled the CBX's torque output with apparent ease, and it provided good feel and a fairly smooth progressive engagement, except when it was hot; then its engagement was sudden.

An 18/42 (2.33:1) final drive sprocket combination is used: the same ratio as last year, despite the fact Honda has switched (as with the 1980 750K- and F- models) to a #530 (3/8-inch width, 5/8-inch pitch) chain to reduce noise levels. Because the 1980 chain uses higher quality materials, it will last longer, given proper care, than last year's #630 (3/8-inch width, 3/4-inch pitch) chain. Absolutely no lube from the endless O-ring-sealed chain gets to you or your passenger, thanks to an effective plastic chain guard. Adjustment, however, can be somewhat of a hassle because of the CBX's voluminous mufflers.

Both fenders are plastic, the front glossy and the rear somewhat matte-finished. A two-bulb taillight takes up the rear and provides security should one lamp fail.

All four turn signals are rubber-mounted, a tribute to the Honda's post-600-pound weight. We dropped our CBX while parking it and discovered that the rubber turn signal mounts could not cover for a vast multitude of parking lot sins - we broke a signal and a mirror anyway. No fault is due the side- or centerstand; both work well although the sidestand foot does not come far enough out to provide the bike its firmest at-rest posture.

Germany provides, as far as we know, the only non-Japanese part for the six. This component is the quartz headlight bulb-which fits inside the Stanley headlamp lens and reflector. Replaceable, the halogen lamp emits a stunning bit of brightness, although its beam is not as sharply defined as that of the Bosch quartz-iodine lamp. The CBX headlamp is still first-rate.

The CBX can be deceptive. It's large and heavy, but on the road, the Super Sport feels agile. Despite its good manners, you can't ignore the Honda's mass. For a rider with experience at picking lines, the CBX is a willing tool. While it may not be easy to switch lines in the middle of turns, the Super Sport can bear with you to an extent. It leans readily thanks to its (moderate) wheelbase, tire shape and quickish steering geometry. Thus short-notice heeling is controllable and not the least bit offensive.

   

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