There are some British bikes that the moment you ride them you know are right. Whilst doing some research for the Good British Bike section I came across this example, a working bike with numerous mods. The owner was keen for me to have a ride despite being a devoted UMG reader. His ulterior motive was the need for a quick injection of money. He knew I loved the peculiar torque of the Commando engine which through a couple of mechanical tricks he’d more or less replicated.As well as a shocking dose of power there was also sublime smoothness. A notoriously difficult trick to achieve on a big twin in a Slimline frame.
I was sold on the babe. It was the best Norton twin I’d ever experienced. Fell for it just like that. The 650SS was externally road weary, could’ve done with a good wash and paint job. The fundamentals were fine. The frame, tyres (universal Roadrunners) and brakes (TLS front) were well up to modern roads. I tried to haggle but the grin gave me away and I ended up parting with thousands rather than hundreds. Readers who expect me to take my own advice will just have to put it down to extreme lust over an extraordinary example of the British breed.
A brief acquaintance with any motorcycle can be intoxicating, long term's an entirely different ballgame. Mere days or weeks can turn a thrilling experience into hell on earth. More so with many old Brits than most bikes. The Norton's proved the exception in the past month’s riding. Even to the extent of neglecting the Speed Triple in its favour. in part because the local cops had taken it into their heads that ton plus speeds could not be tolerated and every time I went out on the triple I was paranoid about stake-outs and road blocks.
Riding an ancient looking Norton twin was sufficiently confusing to have myself dismissed as of no consequence despite the fact that I could push the old dear up to 125mph! The Slimline frame, recently rebuilt short Roadholders and newish Girlings were not fazed by such excess. A new Triumph held the road more securely but was a much heavier device to throw through the tighter bends.
The big problem with the Slimline frame was that it gained its strength through using high grade steel in relatively thin sections, which was fine for strength but did nothing for the absorption of vibration. When the 650SS became the 750 Atlas the engine tried to shake the frame to bits when used in anger. Using typical British logic, this obviously meant that the frame needed to be replaced rather than the motor. Enter the Isolastic mounts and Commando line.
My particular engine was particularly smooth, only threatened the frame when taken to silly revs. Then a gravelly, graunching vibration took hold of the whole chassis. But tall gearing meant that fourth would never reach such heady heights. Also, that the clutch needed a little slip on take-off. The combination of heavy gearing plus the concentration of power and torque below 6000 revs gave the mill a relatively easy time.
There was more to this smoothness than mere gearing, though. The engine was a mix of race components and stock. The crank was dynamically balanced and fitted with Superblend bearings (the uprating of the crankshaft for the 750/850 was minimal) with extra metal welded and machined into the crankshaft for added support. Con-rods, pistons, valve rockers, valves and pushrods were all race items, lightened and polished.
The lightening of reciprocating masses went a long way to explain the smoothness. The engine being conveniently separate from the gearbox, some rubber mounts from a Kawasaki had been robbed and fitted in extra thick alloy engine mounts. The pistons were high compression ratio, the cylinder head gas flowed but the cams stock. This is as much intelligence that I could gain from the owner, who enthused that he wanted to combine smoothness with high efficiency and Harley type torque. I have no idea how much work this took but this 650SS surely shows up how wrongly developed was the Norton twin.
Further aids to smoothness were electronic ignition and a belt primary drive. The latter alone effects a miraculous modernity to the stock four speed transmission which actually snicked home with a greater precision than my Speed Triple’s box. Such conversions are expensive but stock chain primary drives on old Brits (and Harleys, if we want to be nasty) are so fearful that it’s a compulsive purchase for anyone into serious riding.
The only sign of age was an oil leak that left a good dribble when the bike was left standing for more than five minutes. One of the joys of vertically split crankcases. After I'd cleaned off the road dirt the alloy and chrome turned out to be excellent but the paint was a faded mixture of black and light grey. I felt inclined to pay for a quick cycle part respray, the engineering hidden within the alloy seemed to demand it. Old bikes like this insist on the odd bit of tender loving care.
Maintenance consisted of valves, carbs (I’m looking for an SU conversion), oil, bolts, drive chain and polishing every month. I did find that oil consumption was high and that occasionally the oil would hide in the sump making me think I'd run the thing dry (but I was aware of this trait from past misadventures). I always carried a litre bottle in case I ran out.
I did push the bike to high velocities, anything up to a ton as a cruising speed, with brief bursts to 120mph when circumstances demanded. Other vehicles viewed the appearance of a speeding relic (the bike not I, although I don't know...) with dismay but I thought it was a great game to play with the traffic and tarmac on a thoroughly ancient motorcycle.
There were dangers, as well, or maybe they were a part of the visceral thrill of such adventures. Repeated hard stops from high speeds, as when attacking a series of bends, caused the TLS drum to fade. Not to nothing but the heated, distorted drum took the edge off the braking. Both shoes and linings were to racing specs, therefore rather harsh in action with none of the gradual softness in the wet of the stock brake. A huge amount of muscle was needed to stop in a hurry, which made for some amusing antics when I did the same trick on the Speed Triple. Stoppies rule!
If the brakes made life interesting in the curves, the aged chassis gave pause for thought when hurtling along at speed. Unwanted but persistent visions ran through my mind, of brake hubs or the high tensile steel of the frame cracking up. What was left of my body being scraped up by the ambulance crew. Old bikes do that to your mind after a while. Anyway, part of the monthly service was to check over the chassis for any cracking. Bloody huge potholes, sleeping policemen and the odd thrown brick or marauding dog do stress these old frames but I suppose if it can survive the Isle Of Man it can survive anything I might throw at it.
One shocking thing about blasting about on the 650SS was how cheap it was to run. I'd just about accepted that flat out work on the triple would only give 30mpg and was expecting 40 to 45mpg rather than the 60 to 65mpg the Norton turned in. I can only assume it was down to the gas flowed head, polished components, lack of noise and pollution controls, efficient cylinder head shape or just the mere luck of a combination of favourable features. No-one believed me when I mentioned this trait, so I don’t expect you will either. But there you go!
Flat bars and rear-sets gave a comfortable ride, except for the bumps that the short travel suspension let through. Leaping back on the Speed Triple I thought I was in luxury city. Well, after 30 years you do expect a little bit of progress! A typical ride consisted of a hard thrash of 200 to 300 miles, then a wander around some part of the UK’s heritage (the more depressed areas have the youngest women in the shortest skirts and sexiest stockings; a phenomenon | wouldn't mind doing a doctoral thesis on if someone cared to come up with some dosh) or a bit of dodgy business, and then another thrash home along a different route. 400 to 600 miles in a day did no harm to the bike and left me feeling as fit as a racer on a run of luck.
The only incident of note, a potentially catastrophic one at that, was when the return oil pipe came adrift. That happened in town, where the Norton was happy save for the need to slip the clutch below 10mph. Some helpful pedestrian leaping up and down as he ran alongside pointing at the bike. I thought he was another classic admirer, perhaps a Norton fanatic enraged by the non-standard nature of the beast. Eventually, I gave in, looked down at the back of the bike to see oil spurting like blood out of an artery.
The pipe had actually broken but the ped said not to worry, he lived nearby and had a workshop where we could fix it. I can’t see civilians rushing to help someone mounted on Japanese machines but then they probably wouldn't do the same trick. Towards the end of the first month of ownership I had a go on a RE Continental 250 single, another nice example of the breed. I wanted to buy this as well but two bikes in the hallway was more than enough and three would've verged on the greedy. Still, the lightweight RE made both the Norton and Triumph seem rather pudgy. I began to start plotting to lose 50Ibs from the 650SS, a bit of madness with the electric drill, 2-1 exhaust, GRP cycle parts... nah, spoil the whole balance of the bike, keep it as it is.
After all, the past owner had gone to extreme lengths to sort the bike out. Stock Norton twins after 30 years, or more, of wear and dubious rebuilds are something of a lottery. That’s true of all British twins but the 650SS engine wasn't the best of the bunch, the BSAs being stronger if stodgy and the Triumphs smoother and more powerful, but a well sorted example of the breed installed in the clever and almost sublime Featherbed chassis can work out as a quite extraordinary experience. Good searching, mine's not for sale.
Johnny Malone