One of the defining machines of the '70s was the Norton Commando. Launched in 1968, it went through many variations in styling, capacity and guises. Its Isolastic engine mounting system was one of the features of the bike that eventually became a whole range of models and grew from 750 to 825ccs. Production racing was big for the manufacturers of the time and the Norvil Commando was the racing derivative that became famous around the race tracks of the UK and the Isle of Man as its bright yellow livery saluted the chequered flag ahead of the opposition.

The subject of this particular test came from the very best of stables - Gus Kuhn in fact. Proprietor Vincent Davey was a prime exponent of extracting the best from Norton engines and fielding race teams that were the next best things to actual works participation.

Production racing was big in the late 60s - early 70s. There was a TT race and the '500 Miler' to contest as well as others, and a full supporting field of National and club events.

AFTER ACKNOWLEDGING THE chequered flag, knocking it into fifth and relaxing, I reflected upon the differences between this latest Commando and the remotely similar model tested some two years ago. The first production racers were not for the unwary or the clubman wanting to play at the game. It took the Mick Andrews of those days to tame them and put them ahead of the field, which consisted almost entirely of Bonnevilles . The Commando of today is a different kettle of fish and it has the "triples" to contend with now. But I'm getting ahead of the story.

This particular racer test came out of, of all things - a press conference in one of London 's plushest hotels to launch the latest range of BMWs upon the UK. In case you wonder how some of these so-called journalists get the luck to be wined and dined by the trade for the benefit of having the new models reported in the press, well I happened to be invited as a rider. But it did give Vincent Davey and me a chance to engage in conversation, where we reflected on the one other time that I had ridden a Kuhn machine. This was when Mick Andrew started to campaign "Dave's" first Commando production racer.

Dave told me of his plans for the coming season and how he expected delivery of one of the first of the 100 production racing Commandos that the factory were to build for the 1971 season. Enough said. Dave was getting one; a test by MCI of the only machine produced by a factory especially for the job of production racing was too good a chance to miss. Particularly as MCI has championed the cause of production racing for about five years now.

Kuhns anticipated delivery of the 'bike in time for Jon Vincent to use it in the first round of the Bemsee/Shell production championship on March 7. However, like other customers he was disappointed, and it was just a week before that race, that the 'bike which had contested the Bol d'Or 24 Hour race last year was taken out of cold storage and rebuilt to almost identical specification to that of the works Norton Commando.

This, then, was to be the subject of the test, but the differences between this machine and those that the customers anticipate getting are really only two. These are that the flywheel balance factor is altered in the Kuhn machine and the compression ratio is also a little higher. Compression ratios are, of course, one of the things that may be varied within the rules laid down by the ACU.

The 'bike was completely rebuilt within the week and Jon kept his appointment at Snetterton, finishing in second position though slowed by a mysterious mis-fire on full throttle, which was attributed to a run-down battery. This item was replaced and after collecting the 'bike on my trailer, I arrived at Snetterton on March 14 - a day that blessed our efforts with idyllic weather. The sun shone and the 'bike started easily on hard racing plugs, which was a good omen, indicating that I'd not got myself a temperamental racer that had to be pampered to perform. Things were looking good as I went out at the back of the field to practice for a few laps and qualify for the race.

Usually the fast men try to get out first to get a clear practice run, so perhaps I should not have been too surprised to find myself and the Kuhn fairly welting down the long Norwich Straight, overtaking slower men as though they had stopped. It was very good for morale and though I seemed to be catching everybody in sight (there were some out of sight) the 'bike was not running as well as it might do, since the mis-fire reported by Jon the week previous was still there. But it was still going like the proverbial clappers.

First impressions were that the single disc brake was a real good 'un. I'd campaigned all last season on a Triumph Bonneville where one just automatically used all the brake there was, and hoped when using it to the limit. With the disc you squeezed and squeezed and the retardation got better and better. That I'd have to treat with respect, I thought. Roadholding posed no real problems, it seemed. In fact, I was pleasantly surprised as I still had vivid memories of that early machine, and I think I said in the write-up that it was really a machine for men, or words to that effect. So I finished that session with some hopeful anticipation but a little worried about the persistent misfire which must be taking a few miles per hour off the top speed. Some of the opposition was not exactly slow.

So what of the opposition - well, the machinery anyway? In particular, Pat Wyncoll was riding a 750 Dunstall Norton which had been clocked at 122 mph last year; there was a Honda four in the field and a couple of Tridents, one, Cohn Agate's, capable of about 120. At least last year it was as fast as my Bonneville and that was electronically timed at 120 mph. There was a lap speed target, too. Fastest T120 lap I'd had clocked was 1 mm 5 1.2 sec so we had several pointers to assess the Commando from, to say nothing of the results that might be achieved. But in racing there is one thing you can never bank on. Luck. And you don't win races without it.

I'D BROUGHT MY TRIDENT WITH ME; it replaces last year's Bonneville. I thought that a race on the Norton in the first event and a first-ever gallop on my new mount should provide an illuminating comparison, but it was proving a reluctant starter. And I did not even know if the carburation was right. Anyway, I took the Norton out for the first race to the collecting area (no, not a race to the collecting area!) to assemble and draw discs "out of the hat" to decide grid positions -number three. Things were looking even better.

Now the Commando always started first kick, as long as one set the pistons just over compression, really worked out the starter crank, and followed right through with a long, swinging kick. A case of less haste, more speed. So when the Union Jack commenced its arc the editorial boot descended with a sickening crunch and in appreciation the motor burst into life, the first of the five gears went in, up went the revs and in went the clutch.

Well, you hear about all the wheelies that one is supposed to be able to do when trying to make impressive getaways on test machines, but then they usually have roadster bottom gear. And with a reason able amount of torque from the motor and a quick jerk on the bars it's not really difficult. But this was a racer with a close ratio set of gears and clip-ons. True, the bottom of the five ratios was very low for a racer, but the front wheel really did clear the tarmac and the Commando took off like the proverbial hound of the Baskervilles was behind. (For the uninitiated, this was a fiendish hound featured in one of Sherlock Holmes's adventures and one would leave the vicinity - Commando style.)

That getaway really was a cracker, because I arrived on the Norwich Straight with a clear view of the next 1,000 yards unobscured by any offending machines in front. The way the arrival was made was a contrast with the first test referred to and really highlighted the progress made by two years' competition. First time I'd aimed the Norton's Isolastic frame through the left-hander into the straight I'd nearly made the ploughed field that runs alongside the track. The ripples on the exit had set the model curtseying like a seasick combine harvester and it required great determination to keep the thing on the required course.

This time the transition from the right-hander, Sears Corner, to the approaching left was made without effort and it bounded over the ripples with no more fuss than my last season's Bonneville had made which was not enough to disturb my white-haired old granny who, of course, regularly screwed the 'Umph down to the village for shopping.

SO, TUCKED BEHIND THE SORT OF nose-cone fairing endeavouring to hide the Everoak Grand Prix, knees and elbows, from the mph reducing effects of the draught which was going by at 120 plus, I noticed that the mis-fire was still apparent and the rev-counter was indicating 6,500, which was the best reading achieved during the day. This was with a 22T gearbox sprocket fitted, giving a top ratio of about 4:17, 5400 rpm at 100mph and top whack of something over 120 mph.

This cannot be too far out, I'd thought, as at last year's Bantam Club Hour Enduro meeting Ron Wittich had been timed on a Kuhn Norton at 123 mph, and this one was slightly afflicted with the hiccups at peak revs and losing a little as a consequence. Low revs, you might think, 6,500. Perhaps, by some standards, but then if the motor is producing its best power at this sort of figure then there is no point in gearing lower just for the sake of seeing more revs on the clock, and as an end result inflicting a shorter life on all the moving parts.

Continuing that argument a little further, the 'bloodline' on the Commando is at 6,200 and this is where gearchanges were made. With the five ratios available it was always possible to keep within the power band which in any case came in below 5,000. In fact, it would pull up from nothing, but that's hardly racing technique and extracting the maximum which is what it's all about. But, one could happily drive through a corner in a higher ratio than the corner would suggest, with the motor pulling lustily at 4,000 something, indicating that it's the sort of machine which a relative newcomer to racing could use to good effect before mastering the ultimate in wringing its neck, yet still stopping short of a pain in the wallet. Further, the high gear technique is the one favoured by Vincent Davey, which is probably why he can say that they have never had a major disaster with a Commando engine and you can't say that they don't get the results.

So, there I was, belting down the straight with chin on the tank wondering just how good that disc brake was going to be. In practice I'd started braking at the 300 yard mark to feel things out, since you can even stop a Trident with the standard tls front brake from that distance. The retardation department was obviously going to be on the ball, but the "feel" with a disc brake is somewhat different from a drum type, and I'd yet to really pin it down hard.

So up came the 300 yard marker board. Sit up, plant a number nine boot on the brake pedal while squeezing the front anchor lever and, I suppose, the brakes actually went on about 270 yards. Excellent - down through the gears, and we arrived at the hairpin bend with loads of road to spare. Quick glance behind to see where the opposition was and all I could see was Agate's Trident. So, head back down, and blast it through the gears up to the Esses.

It's here where one can quickly assess a machine's agility as you flick from left to right, and the Commando proved to be very mobile. It may well be under these sort of conditions that a Commando could actually make time up on a much heavier Three, though at 395lbs the Norton is hardly light. A Bonneville is some 35lbs lighter; a Three is 480lbs. But out of the Esses, going hard, straight for 50 or 60 yards then the prime feature, for me, of the Snetterton circuit: Coram Curve. A long, long, right-hander where any ground clearance problems show up, to say nothing of navigation over a couple of ripples on the way in, just as you are committed to a line.

Ground clearance was certainly no problem; I guess it was hardly likely to have been on reflection, as the bike had been ridden by Charlie Sanby, who is the Kuhn number one runner - and inclined to run rather rapidly, to boot. Over the ripples and no need for any change of line, crank it over and over until it is nerves, rather than any roadholding deficiencies, that determine the limit. Indeed, it proved to be a good machine with which to work off a winter's rust, not having travelled any faster than the legal limit, and in a straight line at that since the last race in October. It did inspire confidence.

Next time down the straight I let the braking wait until the 250 yard mark and now the worth of the disc brake was beginning to notice. The front end of those typically Norton forks - firm of action and relatively short of travel - were dipping hard under the retardation . There was still road to spare. Next time a fraction later, and the back end was beginning to hop about until, by about lap five, I'd got it down to near the 200 yard mark and was unlikely' to improve on that without the spur of competition.

That did not materialise because the Commando, in spite of its mis-firing, was undoubtedly the fastest thing in the race, which did not give the opposition too much of a chance. Rounding Sears Corner with right boot kissing the tarmac, the motor spluttered a bit more than usual, coughed, picked up, and then died for good, leaving me coasting down the straight with . No, I'd checked the fuel before starting. But it was gone Gone, that is. That small glass fibre tank had been deceiving, the cutaway underneath had been larger than it looked and in spite of looking plenty I'd only got as far as six laps with a "comfortable" lead. Oh well, back to the paddock in time to hear the reason why I'd retired announced over the Tan-noy. Twit! The opposition laughed like drains. But then, so would I.

Actually, that was the second time that day. As I'd mentioned, my Trident had been most reluctant that morning and had only burst into life at the last possible moment before last practice, when I'd given up hope. Grabbing helmet I'd rushed out for the last few laps without looking in the tank, with the obvious result. Still, it couldn't happen three times. Could it? I'd put seven bob's worth (sorry, 35p) in the Trident, intending to use it in the second race, and the gallon and a half in the Commando to make absolutely sure of achieving the best possible end to the test, and this amount filled the small tank to within a couple of inches of the filler cap.

There was Pat Wyncoll's Dunstall on the front row with my Trident in pole position; I'd lent it to Hugh Evans so that it would at least be run. He was supposed to see if the carburetion was anywhere near and whether it steered. But back to the race, which commenced in the usual way with the 'Jack and threading the 745 cc twin through to the front, banging the throttle wide open through the gears until 6,000 showed first, second and third to arrive at Rid Corner on the heels of my Trident and the Dunstall.

Under Hugh's elbow and after that only Norton down the straight, into his slipstream, out, and by with ease, in spite the odd cough from the engine department, into the position that every racer covets. No mistakes this time, an uneventful , enjoyable ride on a machine every bit a racer. A machine which, when bug-free, must be fast enough to win nearly all production races - if the rider is good enough, of course.

The latest geometry of the forks and the racing head steady providing roadholding that compares with the best; the disc front brake ensures braking as good as anything I've yet to enjoy; the five-speed gear cluster gives meteoric getaway off the line, and bonus acceleration through the gears. The performance would stand you in good stead in an open racing event, let alone production race where, with the ability you must be in with a very good chance indeed.

After acknowledging the chequered flag, knocking it into fifth and relaxing, reflected . . . . Well, if you have £849 and the courage of your own convictions plus the ability, you could win races on this Commando.

PS. My Trident finished second, after running out of petrol on the last corner. Memo to diary: petrol is not so expensive - must get a bowser to follow me round, anyway.