There is no point trying to run a sixties Honda CB450 unless you have a few bikes for spares. Fortunately, many parts are interchangeable with the later CB500T, of which there are still many cheap, rat examples around. My 1966 four speeder came with a garage full of old and dead CB450s and CB500Ts. The bike was a sound runner with 37000 miles done, the machine and spares costing me £500, which I thought about right. I have owned the machine for three years and put 58500 miles on the clock to date.
The CB weighs 410lbs dry and is quite a heavy bike to haul around at most speeds. The suspension was original at the front, Girling shocks at the back. The front forks bounced about rather a lot and twisted when the drum TLS brake was used in anger. The back end was so rigid that each and every bump was fed directly into my spine. The frame was a single down-tube affair, designed on the lines of an early sixties Bonnie. It just about managed to hold everything in line.
The large vertical twin engine dominated the machine, with its huge cylinder head casting containing such delights as double overhead cams, huge valves, torsion bar valve springs and rockers sat on eccentric shafts for adjustment. Developing 43hp at 9500rpm, the engine was still capable of revving to 10000rpm and putting 100mph on the clock.
Power took off from 6500rpm, below that the offbeat exhaust note growling discontentedly mixed with a large amount of vibration, although the engine was able to plod along in top at as low as 2000rpm without tearing the transmission apart. Ah, that transmission. It wasn’t a case of snicking the bike into gears but of very gently operating the gear lever until the gears meshed and then hoping that they didn’t slip out again. It took me six months to master the technique, but it is a good anti-theft device. The chain wasn’t much better, needing daily adjustments, although the fact that I kept using the chains that were in the spares rather than buying a new one doubtless did not help matters.
Right from the start the Honda was plagued with electrical problems. The battery kept boiling over, bulbs kept blowing and the indicators worked only erratically. The wiring was a complete mess and the rectifier looked like it had dissolved into a molten heap many years before. I eventually found some reasonable electrical components from the spares and sorted out the wiring. Battery life is still only about six months, they just don’t want to last longer than that.
The bike was also a right bastard to ride in town. The engine started to overheat, making neutral impossible to find and the clutch drag. Waiting for the lights to change with the clutch pulled in, the Honda slowly moved forward forcing me to grab the front brake, the engine stalling dead. The motor was easy to start hot on the kickstart, the electric boot having long since burnt out its brushes. Cold starting was another matter, the bike often needing twenty or thirty kicks before it reluctantly stuttered into life. Perhaps I lacked the correct technique, but practice never improved its starting ability; neither did new plugs nor points.
I tried to avoid town riding whenever possible. When forced by circumstances to spend more than five minutes in heavy traffic, I tried to ride by watching events far ahead so that I arrived at traffic lights just as they changed. Changing into neutral before I came to a stop was also a possibility, but usually it just went straight down into first or plunged straight back into second, about the only time the box acted with any precision (fast take-offs were always fraught with the possibility that the change to second was going to be missed and the engine thrown through the red zone by hitting neutral - I have had 12000rpm on the clock!).
The bike came on standard silencers which were long past their best. I found a set of megas with some chrome still on them amidst the spares, but these produced a massive flat spot at lower revs. The huge 34mm CV carbs could be adjusted for idle but did not have any other means of modification, other than buying jets, which I wasn’t willing to do. The left-hand carb occasionally deposited a large quantity of fuel over the engine, but the carb bowl could be snapped off and the float height altered within minutes.
The engine only stayed in tune for 400 to 500 miles, needing the carbs balanced, the points set and the valves adjusted. The latter were tedious as the clearances were so small it was dead easy to alter the setting when doing up the lock-nut, but at least the adjusting screws of the eccentric shafts were easily accessible from outside the engine as they were set in the ends of cylinder head. Failure to attend to these items produced a flurry of vibration and a loss of the top end performance.
For such an old bruiser, acceleration was more than acceptable, the bike able to blow Superdream 400s into the weeds from 60 to 100mph. With flat bars and rear-sets, 90mph was a comfortable cruising speed, the engine surprisingly free of vibration considering the lack of balancers (the pistons move out of phase with each other unlike those horrid British twins). This worked out at 9000 revs in third or 7800rpm in fourth. Even under such stress, economy was always better than 60mpg, 70mpg often being achieved without thinking about it.
A slight weave was in evidence beyond 80mph and the drum brakes were not really up to repeated high speed stops, fading away to nothing on occasions. Even after I'd fitted stronger springs and thicker oil to the forks, the weaves were still there. There was a steering damper on top of the steering head but it had no discernible effect on stability.
After about a year I had decided that the frame was quite strong, the steering geometry about tight and the suspension total crap. Although there was an initial top heavy feel to the bike I soon learnt to ignore this and quite hairy angles of lean could be exploited before the centre stand tag started to dig holes out of the ground. Performance and handling was better than GS450s, CB400Ns and the like, which was quite amazing for a mid sixties twin. Appearance when I bought the bike was poor, with faded paint, rusted chrome and corroded alloy. After the first year I decided I liked the machine sufficiently to slowly do a restoration job on the chassis. I decided that gloss black on everything that would take it would do the trick. The frame, tank, guards and panels turned out to be made of surprisingly hefty steel, through which the patches of rust had not eaten very far. The chrome and alloy was polished or replaced with better bits from the pile of spares.
By the time I had got the chassis in good order, the motor started pouring out white smoke from the engine breather like there was no tomorrow. Engine out, head and barrels off, revealed that the piston rings had started to break up, luckily seizing in the pistons rather than going on a long journey around the engine. The crankshaft was still OK, supported by four huge bearings, with an alternator on one end and a gear primary drive on the other, a long camchain running off a sprocket in the centre. A typical Honda twin design. There were serviceable spares to hand, so I was not off the road for very long.
That strip down occurred at 53700 miles. Since then I have not had to touch the engine save for regular maintenance every 500 miles (which includes a paranoid engine oil change, the bike having a wet sump rather than the separate oil tank so beloved of the British manufacturers of years past). There is a centrifugal oil filter hidden in the depths of one end of the crank but I don’t have the tool to extract it, so god knows how much gunge is in there.
I get some pretty funny looks from other motorcyclists, they are not quite sure what it is I am riding. 0 to 60mph in about seven seconds means it can make most cars look pretty sick from the standing start. I like the bike a lot. It’s a bit temperamental but has loads of character and charisma, with that huge hulking engine it has to be the first of the Japanese classics.
I have been offered a thousand notes for mine, but managed to resist the temptation. I am now trying to build a second one out of all the parts that came with the bike... it will probably have an engine more CB500T than CB450 but no-one other than myself will know the awful truth.
Wilf Duncan