A TALE OF TWO ZEDS
He doesn’t do things by halves, does our Ralph! In this issue, he’s starting a Double Zed Building Project! One standard, one not so…
Ralph once more, beginning a double build!
Anyone who has ever met me will know that I am a massive Zed Head. To me the Z1 series of bikes are the most aesthetically pleasing bikes ever created.
Not just does the mere sight of a big Zed make the manliest of chaps go weak at the knees and get all emotional, they are also a very practical, fast form of transport.
In the 1960s the affluent US market was key to making money out of making motorcycles. KHI (Kawasaki Heavy Industries) was well aware of this and set up a project team in 1967, headed up by Gyoichi ‘Ben’ Inamura, with the code name N600, which gave no hint about the way it would change lives forever. Initially the bike was to be a 750cc inline four with double overhead cam-shafts. Japan’s biggest motorcycle manufacturer, Honda, were also working on a similar project, the single overhead cam CB750 which they proudly unveiled to the world at the 1968 Tokyo motorcycle show. This was quite a body blow to the smaller manufacturer in Inamura, but they decided that the only way forward was to create a bigger and better bike to finally knock the mighty Honda from the top spot.
Kawasaki experimented with various sizes of engine before deciding in 1970 that 903cc capacity was the optimum and so the New York Steak project was on its way to making history.
Once a tangible prototype was created, they dressed it up to look like a CB750 and tested the stuffing out of it, all the time making tweaks, corrections and improvements. In September 1971 they felt that they had cracked it and the order was given to start mass production. By February the following year they had some pre-production test bikes for the final shakedown testing and mass production started in early in May. On September 16 at the IFMA Motorcycle Show in Cologne the groundbreaking mighty Z1 finally was unveiled to the world.
The 82bhp superbike was an overnight success on so many levels. It was fast beyond anything previously available to us oily oiks, who could afford the Hire Purchase repayments on the expensive £1088 monster. Those with the wherewithal to own the mighty Kwaka were rewarded with virtually celebrity status amongst their biking peers.
For many of us, back in the day, we could only dream of sitting astride our own big Zed, but as the years passed and our children finally departed to annoy someone else, many of us have managed to finally realise our dream.
You still need to be seriously minted to buy a pukka original restored Z1 that pleases a rivet counter, but most of us can pick up a later model or less fashionable
big Zed in less than perfect condition for home restoration at prices that are more realistic for the less affluent amongst us. If you’re not up to your nether regions in purple folding then Z1000STS can be picked up. The ‘Limited’ models (pseudo customs) are also less in vogue, but can be made to look just like the more sought-after Zeds with a bit of guile, some extra parts and a splash of paint. I like all the big Zeds and with a limitless budget and with a massive warehouse I would have one of each as well as lots of ‘Ralph built’ customs.
Some years ago, in an effort to rid myself of my mid-life crisis (HardlyGoesalong 1450 Dyna Glide) I took a 1976 Z900 A4 in part exchange from a friend who wanted to start his own mid-life crisis. It was very gently customised with period stuff and I couldn’t decide what to do with it. She Who Must Be Obeyed rode it for a bit, but then decided she preferred her Stinky (Z650), so it lingered in the lock-up for the last five years whilst I couldn’t decide whether to fully go to town on it as a period custom or back to standard; either would be costly.
Then a friend of mine in the Z1 Owners Club lost his garage and so had nowhere to put his bikes, one of which was another Z900A4 that had been in bits for some considerable time. He called me up and told me of his woes and said he had to shift the bikes on ASAP and he wanted me to have the Z900A4, knowing I would build it up and look after it. There was also an ST which I rebuilt and sold for him. So now I had two Z9s and that made me very happy as now I know exactly what I want to do – one absolutely stock and one as a proper period custom. Having sold the purple peril (H2C Petrol cooled ozone basher, see the still-ongoing restoration on page 88), I even have the dough to do justice to both bikes.
The stock bike needed the frame and allied parts powder-coating, so the first job was to grab everything that wanted powder-coating and ensure that everything was removed that wasn’t to be clad in polyester. Because I want this bike to be original, I removed all the stainless fasteners and tucked them to one side. Post lockdown the powder-coaters were inundated with work and I had to take my place in the queue. All the parts were chemically stripped initially to remove any previous paint finishes and coatings, followed by a severe grit blasting to remove the last vestiges of coatings and give a good key for the new covering to attach to.
Nick, the generous donor of said bike, had bought lots of stainless parts for the project, and whilst I love stainless fasteners and used lots on my ‘Ole Gurl’
(1977 Z1000A1), this bike is to be original, so I’m grabbing all the original fasteners I can find, wire-wheeling them, and taking them to the zinc platers to be made like new again. All the stainless won’t go to waste as it will adorn the ‘lairy upstart’ version.
Whilst the Big Zeds were a well above average quality motorcycle and often over-engineered in places, the majority of steel parts were zinc plated. This is a sacrificial coating which gives a pleasing finish, but the zinc coating being electronegative to the iron in the steel is designed to corrode first, protecting the steel part underneath. In real terms this means that the parts need to be replated from time to time as the coating disappears. Chrome offers better protection and is far shinier, but far more costly.
Bolts et-al made from marine grade austenitic stainless steel can be pretty much thought of as fit and forget, with a few caveats. The zinc-plated mild-steel fasteners have a superior tensile strength to austenitic stainless steels and don’t
suffer from thread galling. Thread galling or ‘picking up’ can be reduced by using a product such as FERROSLIP on the threads. Visually austenitic stainless has a slight yellow tinge, which is massively increased with heat, which is why exhausts headers tend to end up an increasingly dark straw colour and cheaper grades of stainless will end up brown.
Oddly, not all stainless steels are as resistant to corrosion as one might think. Most marine and automotive fasteners are made from either 304 or 316 austenitic chromium-nickel grades. Knives and cutlery tend to be made from the 420 and 440 ferritic and martensitic chromium alloys, whereas cheaper stainless car exhausts are from 409 which contain only chromium and iron. There are other grades like the 500 and 600 series alloys. Most old bike fettlers will buy the commonly available fasteners in either the marine grade 316 (A4) or the cheaper 304 (A2). Some CNC machined parts will be made from 303 (A1) which is more easily machined. I will quite often buy fasteners, machine the markings off the heads with the lathe and then polish them to an attractive mirror finish. One last point on stainless is that the austenitic grades ‘work harden’. Because of this it is essential to use properly sharp tools to cut it. Blunt or dull tools will not only fail to cut, but also will actually harden the material to the point where even sharp tools will struggle. So the rule is, ‘If it doesn’t cut easily get a sharper tool’!
There will be no stainless on the ‘Stocker’ so I’ll be hunting high and low for original fasteners – so, let’s begin!