Sunday, 11 February 2018

Honda CB900



Trying to take a Kawasaki GPz900 with a six year old Honda CB900 wasn't, perhaps, the sanest way of spending an evening. I figured that I was in with a chance because the GPz jockey was wearing new black leathers and didn't look at all happy perched on the Kawa. The road was a wide two lane carriageway with enough room to pass a car without crossing the white line. There were long straights where the Honda was screamed at the redline in fifth to keep up with the more powerful and aerodynamically efficient GPz. If there hadn't been any traffic or violent bends then the Kawa would have disappeared off into the sunset. The GPz was reluctant to ride around cars on the bends and didn't have the nerve to blast away at cars that had the audacity to drive too near to the centre of the road.

The Kawasaki was three cars ahead. The road was just starting to curve to the left. The pace was slow, sixty or so. Flicking down the box to second gear, a handful of throttle and the clutch let out with a bang , the bike wrenched towards the centre of the road, squirming as the front wheel followed the raised surface of the white line. The back wheel jumps off line as power is momentarily lost as third gear is engaged. The speedo flicks past the ton as the CB comes parallel with the final car. It has to get past because it needs to cut across the road as the curve tightens up. Backing off the power at this point would send the Honda veering off into oncoming traffic. Fourth gear, the bike a foot over the wrong side of the road, the car driver decides he wants to race. But I'm having none of that, I'm far enough past the car to wrench the Honda upright and make a straight line out the final arc of the bend. I get blasted by the driver's horn, but my straight line takes me inside the GPz leaving me a little ahead as we exit the curve.

I struggle to turn the Honda out of the gutter, directing it across the front of the Kawa, revving the engine into the red in fourth. If the images in the mirrors were not so blurred I'm sure the GPz pilot must have looked surprised at this manoeuvre. But the movement is a little too sharp. To line the Honda up with the direction of the road requires another vicious wrench on the handlebars. This happens as the front wheel hits the centre line again. The Honda reacts by flipping the handlebars out of my control. They go from lock to lock, but settle down almost as quickly as they started giving trouble. This time. The Honda is on the wrong side of the road, level with a car full of kids who seem to be laughing at the antics of the bike. Fifth gear with a clutchless change; the throttle wound all the way around. The transmission objects to this, a small tremor shakes the bike. The 130mph wind tries to wrench my crash helmet off, despite my being crouched down by the instruments. The Honda needs much more than flat bars and reasonably placed footrests.

A long straight, the Honda flat out at an indicated 140mph. The road suddenly deserted - except for a Kawasaki GPz 900 somewhere on my tail. There's no way I can twist my head to find out how close he's getting. The alloy swinging arm and Koni rear shocks are helping to keep the Honda reasonably stable. The extra weight on the front wheel from the flat bars, help to stop the forks from misbehaving. As the road unwinds, there's more time to ponder just how bad secondary vibes from four cylinder engines can become with the rev counter courting the redline. The handlebars are the worst affected, although gripping the tank tightly with my knees kind of make massage parlours redundant. I sensed rather than saw the GPz on my tail. There was nothing extra I could do to make the Honda go faster. I was already skirting dangerously close to the mechanical limits of a DOHC engine that did remarkably well to extract 95hp from a design firmly rooted in seventies two valve/cylinder technology. It was a long walk home if the Honda decided to break a camchain, seize its pistons or tangle its valves; events that were not particularly rare on this machine.

The GPz went past, the rider seated relatively comfortably behind his fairing. I gained a little speed by slipstreaming him, keeping on his tail until we both started to brake sharply for a series of bends. The Honda doesn't like slowing down very much. Equipped with twin discs out front and a single rear disc, there's plenty of stopping power, but if it isn't used carefully the bike can start to jump all over the road in protest. Tied up in knots is an understatement. I was rushing down the box to find second to have an acceleration advantage, when I realised I was going to enter the curve about 20mph too fast. I had time to notice the way the Kawasaki just glided around as if on rails. Braking while putting out too many revs as second finally engaged sufficiently confused the chassis to have the front end trying to go straight on, while the back wheel tried to move outwards. I let the Honda drift over to the wrong side of the road, getting upright and applying some power.
 
This got me around the first curve, the only problems was that there were several more in the way. The Honda weighs 530lbs, all the controls are heavy enough to delight Harley owners and there's enough slop in the transmission to impress Hesketh engineers. This makes any kind of fast bend swinging very tiring. The only way to ride the Honda through tight curves is to keep the bike as upright as possible. Point and squirt, across two lanes of carriageway when possible and hang off the bike like some speeded up racer. I was congratulating myself on some kind of proficiency in this department - at least, I could still actually see the GPz - when the fuel ran out. Now, when the CB900 runs out of fuel it doesn't give any kind of warning, no gentle splutter from the engine. The engine goes dead. The sudden loss of power while the Honda is committed to a particular line in a bend, results in a wildly gyrating back wheel, and a directional change in favour of cutting across the road for a game of chicken with bored car drivers. 

Flicking the bike upright restored the fuel supply for long enough to navigate the final bend and flick on reserve. A glance at the mileage revealed that the Honda had averaged 28mpg. The best I'd ever achieved was 40mpg on a 70mph motorway drone. The usual cut and thrust riding averaged 35mpg, but this was staying well clear of the redline, in deference to the mechanical frailty of the engine, which had 35000 miles on the clock. The engine also needed a pint of oil every 300 miles, so it's an expensive beast to run. Throw in a new rear tyre at 4000 miles and a new front at 5000 miles, together with a new chain at that mileage, and the DHSS needs to increase the dole by rather more than the claimed rate of inflation to keep young hoodlums in the fast lane. But I can't quite see the government understanding this line of reasoning. I easily caught up with the GPz once out of the curves, because there was a police car sitting on the side of the road. I resisted the urge to wave as the Honda droned past on the minimum of throttle in fifth gear to disguise the heady noise the exhaust makes when on cam. At a gentle sixty there was no vibration, and I could actually study the police car in the mirror. It didn't appear very interested in us. At these low speeds the Honda felt very stable and secure with none of the impreciseness found at speeds in excess of the legal limits, and none of the feeling of living on a dangerous knife-edge. The duplex tubular frame had the usual excessive mass and power to contend with; the front forks were never too hot when new, now they were definitely worn and not even the old remedy of stiffer springs did much to help them gain a new lease of life. The addition of an alloy swinging arm helped tighten up the rear end, but the swinging arm mounts are not particularly well designed, so there's still enough flex to make life, er, exciting.

The sight of the police car sobered up some of our high spirits, we were content to run along at more reasonable speeds. This was useful, to say the least, because the road surface had turned bumpy as we began to approach the out skirts of a town. Even the Kawa's back wheel was stepping out of line. The Honda felt as if it was going to flip over and lay down dead. I cursed complacent Jap designers who never had the opportunity to ride this kind of machine on such dilapidated roads. Fortunately, the road was straight, for bumpy curves and 530lbs of malevolent metal don't mix too well. When new, the Honda displays just as bad terminal tendencies. The tautness of the suspension and lack of wear in the bearings is wrecked by lack of damping in the rear shocks and a weak swinging arm. Failure to replace these items as soon as possible results in a bike that exhibits the same suicidal urges as a 1950 Triumph 650 and one that is capable of delivering these vivid kinds of speed wobbles at much higher speeds than that unhappy collection of ironware that has the audacity to claim classic status. If secondhand bikes don' t have these modifications check out the chassis for signs of crash- damage.

Entering town found me trying to keep up with the Kawa as its owner manoeuvred around the cars with the ease of a trail bike owner. Or this is how it seemed, as I tried to obtain some leverage on the handlebars to overcome the Honda's low speed insistence in carrying on in a straight line. Once the Honda starts to change direction, it then tries to flop over, which just about manages to produce the worst of both worlds - poor high speed stability and poor flickability. These problems come to a head in the wet, when things can easily turn very nasty. The way the motor can suddenly turn on the power, so much fun in the dry, can catch the back wheel out, sending it lurching off. The weight distribution, steering geometry and integrity of the frame do little to help bring the wheel back in line. Backing off the throttle solves that problem, but in bends doing that upsets the front end.

What can be corrected by muscle in the dry, results in a series of slides in the wet. At least the brakes are sensitive and don't suffer wet lag. The only solution is to ride very sedately in top gear, while 125 owners shoot past. Engine life varies enormously, depending on the level of abuse and the efficiency of maintenance. The real tough guys can wreck the top end and wear out the transmission by as little as twenty thousand miles. This requires neglect of oil changes, valve clearances and carb balance. A new camchain and tensioner are usually needed by 30000 miles, although this particular bike was still running on the original components. By forty grand it may need new camshafts and a rebore.

Some bikes, that have been ridden sensibly and maintained regularly, are still running with as much as sixty grand on the clock. Bikes with this kind of mileage and with an unknown history are not recommended. Good engines don't make very much noise and shouldn't have any oil leaks. Anything with more than twenty grand on the clock and more than a couple of owners has to be avoided unless it's really cheap. 

I followed the Kawasaki into a petrol station. I couldn't hear the GPz engine because of the noisy Honda exhaust and because the valves sounded as if they were knocking holes out of the pistons. Oil was running out of the cylinder head joint and dripping from some worn gasket under the engine. The rev counter was fluctuating wildly as the engine failed to rumble along at a constant tick over.

As I tried to unlock the petrol cap, I noted my fingers were shaking. I put this down to the secondary vibes, although the quaint handling foibles might have had something to do with it. For some reason, my suggestion to the GPz rider that we should swap bikes wasn't accepted . He didn't seem to believe that I was editor of this magazine, either. Sometimes I find it hard to believe myself.

I decided to let the GPz go its own way. I'd more or less proved that a little bit of craziness could compensate for the Honda's age and inherent failings. Of course, there's nothing to stop GPz owners going crazy, except perhaps the thought of over three grand being on the line. That's enough to kill the spirit of many motorcyclists, leave them cold to the delights of high speed fun and games. I gave the Honda ten minutes rest, to let the engine cool down and close up the clearances. It sounded much happier when I caressed the starter button. As four cylinder four strokes go, the Honda can't compete directly with any number of rival bikes from Jap and Euro manufacturers. I could write another 3 pages on the handling deficiencies. But the main point is the bike's cheap (from £300 up) and it's, er, fun. It was no surprise that when I glanced in the mirror there was a manic kind of grin on my face...

Bill Fowler

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