Smooth SOPHISTICATION
Mildly modded Commando
Maybe you’ve heard the expression ‘yellow journalism’ – a term applied to newspapers which exploit sensationalism to sell more papers. So perhaps when Norton wished to sell more Commandos they simply painted them yellow? OK, I guess not. However, yellow was a flamboyant and sensational colour choice for a 1970s motorcycle. Britain was riding a difficult economy under the Heath government and unemployment had soared to one million (5% of the workforce), hardly the climate within which to launch a new ‘superbike’.
It was the era which spawned donkey jackets, power cuts, miner’s strikes, shocking inflation, silly hairstyles and the Austin Allegro. On the upside, the 70s also inspired the jumbo jet, the microprocessor, Ziggy Stardust, cell phones, Star Wars, Apple computers, the foreign holiday boom and Happy Days. And for a while it was happy days for Bob Trigg’s Norton Commando, which from its launch in 1969 scooped several motorcycle awards and many more chequered flags.
Unfortunately the 1970s would eventually prove devastating for the British motorcycle industry. The BSA-Triumph Group faced bankruptcy. Meriden staged a damaging sit-in and the newly-launched Norton Villiers Triumph Group (NVT) was torpedoed by the cash-sucking Cosworth Challenge project. The coup de-grâce for NVT however was the simultaneous withdrawal of John Player funding and their protracted battle with the Meriden co-operative – an extremely complex story of government intervention and industry ineptitude best told by those in the know.
Before this calamity an extremely buoyant Norton reaped the rewards of success with strong home sales and an ever-expanding market in the USA. An impressive hoard of ‘Machine of the Year’ awards and a captivating advertising campaign helped to further underpin confidence in Norton. Full page iconic adverts such as ‘Beautiful’ and ‘Uncomplicated Sophistication’ elevated the Commando into the top-seller league. Yellow Nortonism was a showroom coup and racing wins in John Player colours could only increase the Commando’s popularity. Posters of a yellow Commando Hi-Rider and seductive blonde soon found their way onto every teenager’s bedroom wall. Superblend was actually superblonde and even Hollywood superstar Clint Eastwood dished out the cool factor astride his metalflake 750 Commando. Thus the Commando added supersexy to its advertorial. Who said the 70s were boring?
This very yellow 750 Roadster rolled out of the Wolverhampton plant on the 16th October 1971, when the Commando was king. Even the mighty Honda CB750/4 couldn’t initially knock it from its lofty perch. An import from the USA, this particular twin was in very poor condition. Shipped to the UK in 2010 as space filler on a container packed with Japanese classics, it was destined for a specialist importer who advertised it online – while it was still in transit – where new owner Mike spotted it.
‘I was looking for a Commando when this one turned up’, said Mike. ‘I was informed the bike was an import after contacting the seller/dealer. What I didn’t know was that it had become stranded in a New York port due to a dockers’ strike. However the dealer offered me a full refund, explaining that delivery was now out of his control. I was extremely frustrated, and follow up discussions didn’t improve the situation. But I’d already decided this Commando would be worth the wait and I ended up tracking it on the internet over seven months and across five continents before it eventually arrived in the UK. It was then registered by the dealer before being couriered to me.’
But Mike’s frustration didn’t end when the bike arrived in Fife, and problems surfaced as soon as he prepared the Roadster for an MoT. ‘I was concerned with the poor state of the Commando, and a quick inspection revealed bent fork stanchions, buckled rims, worn wheel bearings, cracked tyres, seized brakes and a dead battery. Once I’d sorted the more obvious problems, I fitted a new Motobatt battery and attempted to start it. After a lot of fidgeting with the carbs and plugs I eventually managed to get the bike running, but the engine sounded very rough, coughing and misfiring and refusing to tick over. The lights didn’t work either, so I decided to partdismantle the bike and address as many of the glaring faults as possible.
‘I ended up spending over £600 pre-MoT and naturally I complained to the dealer, Andrew Mason. Fortunately, Andrew agreed that the Commando wasn’t in the condition he’d hoped for either and he reimbursed my outlay. I also mentioned that the petrol tank was leaking from its rusted base and immediately I was sent an Indian replacement – although I’d already decided to have the original tank repaired. On the whole I received excellent service,’ concluded Mike.
Mike wanted to get his Commando running and road-tested over the summ mer months as he intended to carry out a complete rebuild the following winter. PartsP were sourced for the MoT; brake hoses, pads, pistons, seals and rear shoes; steering h ead bearings and a rotor and stator, all supp plied by RGM. The wheels were rebuilt by loca al wheelman Barry Spence with Akront all oy rims and stainless spokes. Unfortunately y Mike discovered that the front brake calliper and disc were out of alignment, so the rim hadh to be returned and correctly offset. A ne ew set of Amal Concentric carburettors wass supplied by Surrey Cycles. A short-actio n Tommaselli twistgrip was retained. Whe en Mike inspected the swinging arm bushe es they turned out to have worn oval – so a new spindle and a set of bushes were supplied by Norvil, then reamed and fitt ted. As the seat had also perished a new one e was sourced from RK Leighton.
Mike ran his Roadster throughout the e summer, but became plagued by comb usting oil to the extent that every start-up resu ulted in an embarrassing cloud of smoke, follo owed by puffing exhausts out on the road.
‘ The engine smoking was a drag, and oil mist began to collect around the exhausts and below the crankcases to the extent that the bike began to look uncared for. Changing the head gasket made no difference,’ recalled a sombre Mike. ‘Then one day when I was cleaning the engine with Jizer I happened to notice a crack on the bottom of the primary chaincase.
‘Alarmed, I immediately removed the cylinder head, barrel and pistons and peered inside the inner crankcase with a torch. Sure enough, the crack I’d spotted had been expertly welded on the inside – it was a beautiful weld and fortunately appeared to be perfectly oil-tight. The exposed camshaft and cam-followers were in good condition.
t this point I noticed that the pistons and barrels looked worn and I realised a rebore, new pistons and a valve regrind would be necessary.’
Before dismantling the Commando for a second time, Mike decided to trace the previous owner in a search for some muchneeded history. The previous owner’s address appeared on the Commando’s dating certificate and a simple Google search pinged up a phone number.
‘I was amazed that Google coughed up a contact telephone for the original owner on my first search – Brian, in Denver. I dialled his number and when the call was answered I simply asked, “Did you own a yellow Norton Commando in the past?” After a long pause the hesitant voice crackled “Yes!”
‘So following some hasty introductions I described the Commando to Brian, who was astonished that his old motorbike was now in Scotland. He was delighted to hear how methodically I was rebuilding his P&J, which he admitted would require much TLC after he’d mothballed it before bringing up his family. Lacking the drive to contemplate restoring the mothballed machine many years later, Brian instead parted with the Commando after spotting an advert ‘Wanted Classic Motorcycles – Dead or Alive!’
‘Brian had no idea if his Roadster had ever been raced, or why it was fitted with drilled brakes and cooling fins, had welded crankcases and a 19T engine sprocket – all features he hadn’t fully appreciated might hint of a racing past. Brian assured me that he’d only used his Commando for fun rides and it had been an utterly reliable motorcycle. But how we laughed when I joked that he must possess superhuman riding skills, because it handled like a demented camel when it arrived with me!’ sniggered Mike.
After the l, Mike thoroughly examined
his Commando. Much of the chrome was revived by polishing and Mike reckons the Colorado climate had been kind to the Roadster. After removing and splitting the crankcases, Mike took the engine parts to Simon Linford Engineering (more normally known as a Vincent specialist) to have them expertly checked. He was relieved when the welded crankcases and bottom end received a clean bill of health. However Simon diagnosed a distorted cylinder head, which was skimmed before the barrel was rebored to match its new pistons.
Other engine upgrades included a primary belt drive and a Vernier Isolastic engine mounting system, both supplied by Norvil. A new clutch and gearbox bearing conversion kit was also sourced from Andover Norton, along with new exhausts, handlebar levers and a set of stainless wheel spindles.
‘Although I wanted to keep my Commando standard, I’d read somewhere that Norvil’s primary belt drive was a worthwhile upgrade – the rewards being a light-action clutch and smoother gears. The original clutch had obviously been abused, so I ordered new fibre and steel plates and a new diaphragm. I didn’t want to renew the primary drive only to take a chance with the original clutch.’ emphasised Mike.
‘Vernier Isolastics were a no-brainer for me, as was renewing all the gearbox bearings and oil seals. The only other engine work was to grind in new valves and fit new valve guides, springs and collets to the cylinder head, all supplied by Andover Norton. Other non-standard parts I fitted were Hagon shocks and RGM’s progressive fork springs to help prevent the forks clunking every time I used the centrestand or braked hard. While I was engrossed in the engine rebuild, I sent my frame and air filter housing away for powder coating. The petrol tank and sidepanels were painted and coach-lined by Bike Paints of Cupar.
‘I decided to replace the original exhausts with seamless chrome peashooters and I zinc plated all the bike’s fasteners using an electro-plating kit I sourced on eBay. I was pleased with how well the plated fasteners turned out and how durable they proved to be after light polishing’.
Once the assembled engine was back in its new gloss-black frame, the bike began to take shape. The original Lucas switches and other electrical items were tested by Mike before being added to the rolling chassis.
‘I couldn’t identify the original American electronic ignition unit but it had worked well before, so it was retained. As I’d already invested in a new charging system for the MoT, I was confident the electrics would prove reliable. The rebuild went very smoothly second time around because I was now familiar with the procedure, and in less than a week my bright new yellow Commando was complete and begging me to fire her up,’ chuckled Mike.
‘I was chuffed when it started first kick on flooded carbs and immediately settled into a smooth tickover. Earlier work in balancing and setting up the twin Amals had obviously been worthwhile. I then took the Roadster for a quick test ride. Initial feedback was excellent, both the clutch and gearbox proved to be uncannily smooth and I was pleased with the belt drive; which had transformed the transmission. The bike felt smooth and handled very well – obviously a benefit of fitting new swinging arm bushes, suspension upgrades, Avon Roadrider tyres and Norvil Isolastics. But I was dismayed when the newlybuilt engine began smoking after every startup and progressively worsened over several runs. I was gutted!’ recalled Mike.
He then contacted engineer Simon Linford who had rebored the engine and Simon confidently predicted that the engine would cease smoking after the first 100 miles. To Mike’s joy it did and the engine burns clean to this day.
Another running-in problem happened while Mike was changing the gearbox oil and noticed bronze contamination in the used oil. ‘I could hardly believe my luck,’ groaned Mike. ‘Just as I was starting to enjoy the Commando’s new-found power, I was looking at another gearbox rebuild. I decided to strip the box immediately and, sure enough, I discovered that the mainshaft bush had moved from its seat and was being worn down by the gears. I fitted a new one with Loctite and the problem was immediately cured.