Today Is HistoryDevelopment Patents


Letter in News and Views 292 (sent in by Norris Lockley, Settle) - Gerry Moore asked in N&V291 for information on the revolutionary Kirk Magnesium frame and its inventor, Frank Kirk. The first Kirk appeared in the New York Cycle Show in May 1986 and then at the Cologne Show in September of the same year. I recall attending that Show and being attracted by a large crowd gathered around a small stand. Frank Kirk was displaying his revolutionary moulded magnesium frame to a sea of awe-struck European techno freak cycle enthusiasts. Its reception was incredible.
What those admirers did not know was that the frames on display were actually made out of sand-cast aluminium (Note: according to Frank Kirk they were high purity magnesium), Frank having not at that time perfected the moulding of the molten magnesium. Similarly, cast frames were used by professionals such as Steve Poulter and the Australian Phil Anderson (actually ridden in the Tour de France) to promote the new brand. The advance order book from these two shows was apparently overwhelming and Kirk encountered real problems producing the frames in any numbers at his Basildon, Essex factory. In addition his link up with the Ron Kitching UK sales machine had pulled in large volumes of orders. Kitchings were to do all the building up of the bikes, using SunTour groupsets.
For a period of about two years Kirk Cycles appeared to disappear from the bike scene but resurfaced at a new factory at South Woodham Ferrers near Chelmsford. Having already spent a substantial amount of money in developing both the CAD designed frame and the method of blast moulding it, Mr Kirk found new investors and set up shop to go into mass production. I recall visiting the Chelmsford factory a couple of weeks after it had opened, and only 12 hours after a 'flash fire' during which the magnesium dust had ignited almost spontaneously, causing quite a lot of damage to the installations - just one of the many problems that seemed destined to plague Mr Kirk.
I recall marvelling at some of the claims that the manufacturer made at that time such as the eight seconds that it took to 'build a frame' by blasting molten magnesium under tremendous force along a 'tunnel' and into the frame mould, or the one cubic metre of sea water which, when refined, would produce enough magnesium to blast into a frame, or the sheer strength of the frame itself as demonstrated by Kirk when he drove his Mercedes car over it without destroying it. His two most famous claims for his product was that the 'Kirk' was the world's first fully recyclable frame, it could be melted down and remoulded into anything you fancied and secondly that it was the only true test of a racing cyclists' real ability, because each frame would be exactly identical in every respect, size, weight, mechanical characteristics etc to every other Kirk.
An MTB version was produced alongside the 'Touring' and the 'Racing' models and Dawes took over the distribution, but not very many seemed to actually reach the market. Of those that did a large percentage were plagued with structural problems, such as self-detaching brake bridges. I recall that in 1989 I agreed to try to find importers for the Kirk range in France and Belgium. When displaying a Kirk road bike to an interested distributor in France, I had the misfortune to have both gear lever bosses detach themselves from the down-tube and for the threaded insert in the bottom bracket to work loose, together with the sleeves in the head tube. A Belgian told me of the brake bosses on an MTB dropping out of the rear stays. In short the 'Kirk' frames had very many teething problems, but this should have been anticipated in the development process, and it is a pity that Frank had the pressure of getting the frame on to a very receptive market before the frame was ready to meet its end-users.
There is no doubt in my mind and in my experience of riding a Kirk, and of having one on the roof of my car as I toured around Europe, that the 'Kirk' was one of the greatest 'head turners' that the cycle industry had seen in more than 25 years. More pity therefore that it seems to have disappeared for good.
The last that I heard of the project was that development and troubleshooting costs had escalated out of all control, but that Norsk Hydro, the Norwegian industrial giant and Europe's largest refiner of magnesium, had taken a controlling stake in the company, but even that cash injection does not appear to have saved the Kirk magnesium frame from extinction.
Frank Kirk himself at the time of conceiving the idea of the Kirk was a designer at Ford's at Dagenham. As the story goes Frank Kirk got his original idea for the frame when he was working on designs for some large scale plastic mouldings for Ford cars - the bumpers on the Ford Sierra being the actual inspiration and most often quoted.
I bought six of the first batch of frames produced at the Chelmsford plant and all but two were returned due to the failure of sleeves, bonded to stay in place. My own frame, carefully rebonded in places with Araldite I sold on, and the last frame was the target of a smash and grab raid on my shop window. Despite its niggling faults I still find Frank Kirk's design very attractive.

'Today Is History' by Gerry Moore

Extract from an article in The Boneshaker 165 Summer 2004 (written by Gerry Moore) - The Kirk Precision bicycle frame was the brainchild of Frank Kirk, a gifted design engineer with many years experience in the automative and aerospace industries. He had seen the possibilities of casting technology whilst working as a designer for Ford Motor Company at Dagenham, Essex. The company was producing large mouldings for car bumpers and he saw the potential for using such a system to produce other products. He had had previous experience of magnesium casting, when working for a company making components for Jaguar fighter aircraft and high performance cars. By the 1980s, he became convinced that he could put his moulding and casting knowledge into the production of a cheap and durable bicycle frame.
Magnesium alloy is one of the lightest metals by volume though its modulus of elasticity (its rigidity) is much lower than steel. It is at the same time cheap and environmentally friendly. A cubic meter of seawater contains enough magnesium to make a bicycle frame. But to turn the magnesium salts into metal requires large amounts of electricity hence Norsk Hydro's later involvement. The frame design was carried out using what was at the time a very sophisticated computer, producing mathematical models analysing the criteria of production, stress, ride, performance and styling. He aimed to match the most advanced conventional steel frame.
To his surprise, Kirk found that computer-aided-design (CAD) could not improve on the standard double triangle concept, nor on the positioning of components in relation to one another, as in the traditional bicycle frame design. What the computer did achieve, however, was to design a frame unhampered by the limitations of tubing. In an interview for Bicycle magazine Kirk claimed:
"...the section that represents the down tube on a conventional frame is able to almost exactly follow the axis of torque, about which the whole thing potentially twists, and which accounts for most of the increased stiffness. We were able to use CAD for small fine tuning adjustments and for refining the aesthetics. The computer could predict just what we could afford to change, and what we couldn't."
The frames were to be built by blasting molten magnesium into a mould under force. They claimed that the whole process of producing a frame took only 8 seconds. It has been difficult to discover where the first factory was located. The earliest leaflet gives the company name and address as Kirk Precision Ltd, Unit 4, Hornsey Square, Southfields Industrial Park, Basildon, Essex. At this time there was only one model on offer, a road frame and only one colour, white. There was also only one size available, approximately 22in. The claim was that the frame design would accommodate riders of heights between 5ft 5in and 6ft 2in, using varying lengths of seat post and handlebar stem. Steel inserts were incorporated in both head-tube and bottom-bracket; billed as being replaceable. An aluminium sleeve was fitted to hold the seat-post, but whether these were replaceable or not is unknown. Carbon fibre seat-post clamps and front and rear gear-change hangers were fitted. Kirk suggested that due to the unique construction, every frame would be identical, allowing the only true test of a racing cyclist's ability. He would demonstrate the strength and durability of the frame by driving his Mercedes car over it. The frame would survive unscathed.
The Kirk Precision was launched at the New York Cycle Show in May 1986. Kirk could afford only a small stand at this prestigious event, but the appearance of his neat, girder-like frame caused a sensation. The first European outing at the Cologne show, in September that year, was no less rapturous. What admirers did not know was that the supposed magnesium frames were in fact made of sand-cast aluminium (Note: according to Frank Kirk they were high purity magnesium). Apparently Kirk was experiencing production problems with the magnesium casting technique. To meet the show deadline he was compelled to compromise. The two shows were outstandingly successful. Agents from both sides of the Atlantic fought to represent the new company giving Kirk a real problem. He was aware that despite the heavy financial investment in research and development and in setting up the new factory, time was still needed to perfect his novel method of production. To add to the problems, he had a full order book. As an engineer he must have been screaming for time to perfect the process, but financial investors demand a return, so, despite misgivings, he allowed the frame on to the market. It won several design awards and patents were granted in the United Kingdom, Europe, USA, India, Pakistan, Japan, South Korea, Canada, China, USSR, Thailand, South Africa and Australia.
The first frames were built-up into bicycles and marketed in the UK by the Ron Kitching organisation. Kirk engaged the British professional and Olympic rider, Steve Poulter, to ride a Precision frame with top equipment. He also supplied frames to the Dutch TVM team for the Tour de France. In the USA, the address for the company was given as Kirk Bicycles USA Inc, PO Box 866, Menlo Park, California. This suggests that orders were being handled from the UK. By 1989 two models were available in the USA, for road racing and touring, frame sizes were given as 21in and 22.5in, with two alternative paint finishes; white with red accessories and light blue with blue accessories.
It appears the demand outstripped the capacity of the Basildon factory and Kirk was forced to seek outside financial investment. Probably late in 1989, or early 1990, the massive Norwegian company, Norsk Hydro, became involved. They were, and remain, the world's largest producers of magnesium, and they saw the Kirk bicycle as an outlet for their product. Agreement was reached and three factories in South Woodham Ferrers, Essex, were leased. Little is known about the actual frame making process, but apparently a thousand tons pressure locked two halves of a mould together whilst molten magnesium alloy was injected in less than a fiftieth of a second. Robot handling was used in what was the largest system of its type in Europe. UK marketing was put into the hands of Dawes Cycles Ltd and whilst the Kirk brand name was retained, a new range of models was introduced. The old Precision frame was tweaked, painted cerise, and renamed Genesis. A so-called street bike was introduced in aqua named Ranger. The newly emerging market for mountain bikes was catered for by the introduction of a model called Revolution, with raised chain stays, finished in fashionable black. The American market was offered the same three models renamed Competition (Genesis), a touring bicycle Touring (Ranger) and a mountain bike name City/Trail (Revolution). These models were available in a range of seven colours; white with blue logos, white with red logos, yellow end with grey base, two tone blue, sunburst, dark blue end with white base and Ferrari red ends with white base. Whether the frames were painted in the UK is unknown, but it seems likely that they were shipped to the USA unfinished and sprayed to order there.
For a while the new set-up seemed successful. The design concept was good; manufacturing, financial backing and marketing were now in the hands of an experienced company, so why are they no longer making bikes today? Probably a combination of factors conspired against them. The time delay between concept and production had been too long, problems with the early models were not easily resolved, and the expectations of Norsk Hydro were not fulfilled quickly enough after their massive capital investment. And there were definite reliability problems - a Bath shop sold about six of the MTBs in 1992. All of them came back with broken frames. By 1992 Norsk Hydro had pulled out. Dawes soon cleared their remaining stocks, and practically the only Kirk bikes now seen are those on Veteran Cycle Club rides.
So what was the Kirk magnesium frame like to ride? Early frames had a reputation for breaking. Lever bosses fell off and bottom-bracket inserts worked loose. These problems were sorted out and later models were ok. The item that caused the greatest problem had nothing to do with the frame at all. It was the forks. The first models were fitted with Cro-Moly forks with forged dropouts. These increased the overall weight of the bicycle and were soon replaced with Vitus 979 Dural forks, these in turn were so flexible that they made the bike lethal. Many owners changed to Reynolds 531 forks, to cure the problems. The Tour de France team that rode Kirk frames used Reynolds 753 forks, so it seems to confirm that there were problems with the Dural models. My own Kirk Precision, frame number 1159, is fitted with Vitus alloy forks and has never suffered from any handling problems. It seems that if carbon fibre forks had been available when the frames were in production, potential fork problems would have been eliminated. My Kirk Revolution mountain bike, frame number 201082, was fitted with Rock-Shox when purchased making it an ideal machine. In spring 1989, in New Cyclist, Mike Burrows reviewed the Kirk touring model. His critique was not unkind, the main complaints were that the magnesium frame was no lighter than a steel one and the bottom bracket had quite a lot of deflection. After test-riding if for a while he said 'I have grown quite fond of its chunky feel and looks...'. Surfing the web for Kirk Precision brought forth the following concerns from the USA. Magnesium frames will corrode if exposed...the Dawes Kirk suffered badly from corrosion and frame fatigue...If the Kirk was exposed to heat, it would burst into flames!


The following pictures are from a former Kirk employee (thanks to help from the National Cycling Collection in Llandrindod Wells).

Magnesium Smelting:

Frech Die-Casting Machine (8ft tall and a couple of tons):

Robot Handling (ended up being done manually in the end):

Frame Test Equipment:


From the Staff Noticeboard:

Patents (explanations coming soon)

There were 3 main patents, registered worldwide, but also in Great Britain, the US, the Soviet Union, Brazil and Europe.

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