Wheel Craftsmen in Magnesium Elektron
Since 1973 Dymag racing car wheel’s made by Competition Wheels Ltd. have become an increasingly common sight. Now it’s easier to say who doesn’t run Dymag in Formula One Ferrari, Brabham and McLaren) as Lotus begin the switch too. Who are the people involved and how much of the wheel is their work? We , went to Wiltshire to find out,
“It was in 1971: I knew people figured out how to make gearboxes and engines and stuff like that for the race-car business. so I thought, why not wheels and uprights?” That was the tall Canadian expatriate Max Boxstrom talking recently about the birth of a significant business. Today Boxstrom and Mike Knight (better known for his Winfield Racing Schools in France I direct a company that turns over £350,000 a year, primarily from the production of racing-car and motorcycle wheels. The uprights disappeared along the route to success, but the still-active designer in Boxstrom drew, and currently has Competition Wheels Ltd. producing 100 c.c. Kart engines that reach 14,000 r.p.m. These single-cylinder units are all made for the Zip concern at Hoddesdon: they demonstrate the sort of flexibility and sheer productivity you can enjoy with a labour force totalling 13!
The signs are that this is a company destined for rather bigger things, but what is the background behind establishing a successful business in such an exotic corner of the market?
Knight is probably the better known. As we said, he has been involved in the Winfield Racing Schools for mime time now an intensive course is still held at Goodwood, though business is much better in France but what is not quite so well known is that he was, and apparently still is, a partner in Tico Martini’s competition car construction enterprises in France as well. He first became involved in competition through a karting operation from his home base in Jersey and went from there to Formula Three.
That seems to be where Boxstrom met him, when both were immersed in the world of screaming Cosworth/Holbay 1-litre Ford motors that propelled the machinery in that fantastically competitive era. As Boxstrom says, with a laconic half smile, “I guess you couldn’t find too many 18-year-olds towing their Formula Three cars behind an Aston Martin, so you could say I noticed him all right!”
Knight is the capital behind Competition Wheels today, though Boxstrom allows, “I put some of mine in too. A gesture of faith rather than to really make much difference to our bank balance.”
Boxstrom arrived in the UK when he was in his early twenties and became involved with Formula Three as a driver and a designer. Neither were conspicuous successes, but he persisted on the design side and eventually became reasonably self-sufficient as a freelance designer. There has been some previous connection with this magazine as he was involved with Race Cars International, and their man Tony Trimmer won the Shell/MOTOR SPORT Formula Three series in 1970, even heating a works Lotus onslaught.
Such activities brought Boxstrom into wide contact with the different problems surrounding designing and manufacturing cars for competition. He found himself doing an increasing amount of component work: fuel systems, suspension geometries and so on.
The first Boxstrom wheels came in 1971. As he recalls, “After I had quit Formula Three I remembered that getting hold of east parts was a big problem, especially wheels and uprights. So I had sand-cast some magnesium elektron wheels• of my own. In fact I sat down and designed 3 composite set of wheel patterns, so I could make a variety of rims available. Aeroplane & Motor Aluminium Castings Ltd. or Erdington in Birmingham, somewhat surprisingly took on the small numbers required for the fledgling ventue. Boxstrom then arranged for the wheels to be machined and the chromating finishing process applied.
Boxstrom was looking for some cash in his pocket at this time and he soon found that Motor Racing Enterprises (MRE) at Bourne End were looking after a number of privateers in Babhams. From that introduction it was subsequently possible to sell modified Versions of the wheels to Ron Dennis for the Rondel Formula Two enterprise. A formal agreement was arrived at whereby MRE – who were the first customers for such wheels – would market them and look after some general administration details. Boxstrom was responsible for all the technicalities of ensuring the castings were up to scratch, and so on.
Now Boxstrom was also still involved in bits of freelance designing, and one of the people he dealt with regularly was Martini. They were buying Chevron wheels and modifying them themselves, so the French concern soon offered Boxstrom a deal to supply their wheel requirements. Gradually the number of customers increased. The original sand pattern designs could cope with a wide variety of requirements, so long as they were 13 in. in diameter and had a width between 8 and 16 in. Four main offset/inset combinations were provided and I should note at this point that when racing-car professionals talk about offset they mean from innermost rim to inside facing of the wheel centre: in America the same dimension is referred to as simply, “the drop”. In rallying, saloon-car racing or any other sane sport they talk about offset as that portion of the rim offset from the hub centre, and the inset as the portion inward from centre-line of hub its innermost rim. Confused? lien: we have to talk the racing man’s language, so just remember, when I say offset, I don’t really mean it!
Back at our story, the small-scale wheel operation was growing, and growing. In the first eight months trading some 300/350 wheels were disposed of. In the next eight months the number was more like 500. Even such small, scale success brought its own problems. Boxstrom knew that to make any money they had to make more wheels and lower the production cost of each. The answer was diecasting, but that process involved investing £30 to £40,000 in dies then, and he certainly didn’t have that sort of cash. The sand casting was cheap “We got worried when casting costs crawled from £20 to over £30. In fact we thought that was the end of our world! Machining used to add about another £10 a wheel, so the profits weren’t bad; but to make it a business, it had to be bigger. and that meant diecasting.
“I was coming back with Mike Knight from a meeting at Magny Cours when he casually asked me ‘How’s the old wheel business then?’ I told him I had this diecasting idea. He asked how much it would cost? I muttered a figure … Mike raised his eyebrows, but he stayed interested!”
In fact Knight was convinced enough to back Boxstrom to the hilt and the present concern was established in 1973 from premises at, “a pretty infamous minor racing address … 361 Bath Road, Slough. It hid been Frank Williams’ place, but he’d moved on to Reading and there were all sorts of businesses carried on from there. Howden Ganley actually held the lease.”
Boxstrom redesigned the wheels pretty thoroughly alter he and Knight had bought out the old stock and patterns from Jim Gleaves at MRF, a man who should be credited with putting so much work Boxstrom’s way, including the F3/FF car design that MRE ran for Barrie Maskell briefly before selling the FFs “quite successfully”. According to Boxstrom the original wheels were somewhat over-engineered and it was possible by slimming down the spokes and increasing the amount of machining to save just over 2 lb, per wheel on 3 before and alter comparison. He stuck to the 13 in. diameters, and that is still true of his die-cast wheels today, though there is the possibility of becoming involved in supplying 15 in. diameter wheels for USAC specification cars contesting Indianapolis. Though 1973 saw their first regular Formula One customer appear (Surtees). Boxstrom found waiting for the die-castings to come through tedious. This was not the fault of Sterling Metals of Nuneaton: Boxstrom had anticipated waiting a year for the foundry to produce the dies.
It is quite important to note that those dies remain the property of Competition Wheels. Important because they had discovered the hard way how vulnerable they could be to foundry policies: Aeroplane Motor provided a superb service, but when they had a fire next door to the magnesium sand-casting activity they shut up that shop. Finish, just like that. Now the business had already decided to go for die-casting so it was not too much of a blow, but when Aeroplane & Motor were forced to cease work Competition Wheels went to Kent Alloys of Rochester. Apart from the fact that they were hanging on for the die-cast examples, it seems the link would not have lasted long Kent Alloys also stopped workIng with magnesium shortly after Competition Wheels had their first die-cast Dymags available.
The first recipient of the-cast Dymags (still in the same four spoke design) was Jo Marquart in the days of Modus, but of more long-term significance was a call from Ron Tauranac. He had drawn up his basic Ralt designs and now he wanted some wheels. No need to ask if he’d done his sums correctly! As Boxstrom now says, “If Ron calls you then there is no doubt you will be doing business!” One of the longest standing customers of all is also French. the giant Renault concern Boxstrom records, “We had contact with them in a funny way. I supplied some of the old sand-cast wheels to John Coombs when he was running the Formula Two cars. they rang up a year later, wanting to know if it was all right to run six-year-old wheels.”
Things developed from that point on, and it’s nice to know that Le Mans was won on a British wheel, and they are still in use for Renault’s now escalating Formula One programme. The point about “liking” and there was quite a kerfuffle over this a few years ago with particular reference to magnesium elektron wheels -is not lost on Boxstrom. He felt: “It’s the business of the wheel designer to make sure of the original strength. If the wheels are kept clean and no growth is allowed to build up, so that the chromating process is still intact and protecting the wheel, the life is not a problem. The whole business of wheel corrosion is bound to be worse in rallying,” In fact rallying is just where we can expect Competition Wheels to next make their presence felt, but first we enquired what sort of testing procedures they employed. The answer lies really with two outside concerns. Sterling Metals x-ray every casting and it goes through “a mechanised Ardrox process,” as Boxstrom describes It. In fact the penetrating dye is applied via a dip and then inspected. Thee design itself, prior to production, goes through hell at Ruben Owen. T|hat famous concern and Boxstrom have concocted a revised version of the standard Wohler test, which “Timed a beam to the hub with force applied to one end and led out through the hub and the flange of the wheel. “We decided this was not realist, so we employed a steel drum, a tyre inflated to three times the normal pressure and the beam. This allow us to apply stress to both edge of the rim as well as the centre. Our standard test is non two million cycles of pressure applied to the beam end at a force equivalent to 2,000 lb. ft. Since the wheels still don’t fail at that, this is the practical limit of what we can do.”
The current range consists primarily of die cast formula or sports racing wheels in magnesium elektron, but they still do specials by sand casting where it’s not worth the tooling-up of dies. Prices range between £65 and £198 per wheel: Boxstrom says one can use the figure of £11 – £12 an inch as a guide, but there are obvious discounts for very large orders, which are rare in this business anyway. Next year they hope to make a range of wheels to suit club racers which will be considerably cheaper than the sand-east specials they do supply to Some of the more prosperous Sports 2000/FF2000 runners today in six rim sizes.
The main die cast range covers a design that will cater from 8 to 11 -in. rims (all 13 in. diameter unless otherwise stated, and then not die-cast) and this wheel can be used either for the front of a Formula One/sports car or at the rear of a Formula Three: the stresses are quite similar so far as Boxstrom is concerned.
The rear wheel design is a patented two-cone (outer and inner) design. This is bolted together with an aluminium collar and two 0-rings in the centre to provide a strong light wheel from 3 to 70 in. wide. For Some special combinations. of offset they can usually cater by niggling around with cone widths … but it’s quite possible that for something really special one will have a two piece with one “half” cone die-cast and the other sand-cast.
Inevitably this is where Lotus enter the scene. As well as making everybody think about wider track they have taken delivery of some specials that measure 11 by 13 in. stock size but have their thinking on insets throughout. Others making wing cars are apparently following along the same path tucking components out of the airstream. … “We have been asked to look at the rears now,” says Boxstrom. What he does not say is that his work will probably be required to mate with the forthoming 80 design, though we were discretely just told, “it’s a very special design.” Since the go is said to be a wing-less car one wonders (frivolously) whether Chapman has finally succeeded making the wheel generate downforce too…?
Another relevant factor at the rear is the arrival of Skefco’s third generation bearings which are generally allowing designers to kink at smaller Insets. Last year the company found they were making 18, 19 and even 20 in. wide wheels for their Formula One customers: this Year its mainly 18 in. but with the different inset trend described. I must make it clear that Lotus are presently only using the Dymag on the front; Speedline, their suppliers in recent years, make the rears at present.
As with the karting engine, most of the Competition Wheels’ opposition comes from Italy. McLaren are Campagnolo muounted and the advertising for John Brown Wheels says that Momo wheels are used on the Brabham (road and steering) in line with Lauda’s endorsement. However, the design is basically one that Brabham have used for a while. Ferrari are contracted to Speedline in Italy.
Magnesium Elektron of Manchester are the sole suppliers Of this material and they also undertake the recycling of the expensive metal removed in the machining processes. As Boxstrom wryly commented, “We don’t make wheels – we make swarf.’’ The remark has more than a grain of truth. As a guide we were told that 10 kg. of material (22 lb.) goes into the manufacture of a 7.7 lb. wheel! The Formula One teams go even further than this wheels for the category are subject to a great deal of extra machining as they pursue the ultimate in light unsprung weights: if the car crashes and bends a wheel (more likely than shattering we were told. contrary to popular conception based on rallying) then that’s just too bad. Even if the wheel goes under impact that’s not a bad thing either – it may have saved the next expensive link in the suspension/monocoque. If not, the Formula One people seem happy enough to absorb cost, looking for a competitive edge rather than crash in this commercial days.
The scene inside Unit t. the neat sandstone building on the newish Leafield Industrial Estate, Corsham, Wilts., is divided into an unpretentious one-floor machining shop and the offices at one end of the building to support such production. Above the offices are a small stores and wheel assembly area where the chromate and dip seal processes also take place. Those two-piece rear wheels are attached by either six (the March and ex -March men school of thought) or eight bolts with drive peg holes supplied to order. The alloy collar actually takes the shear stress, but the friction of torqued-up bolts and centre nut locking is said to provide more than enough friction to keep both “halves” together.
I am only sorry space cannot permit us to fully explore how the wheels are machined from dull gold castings to shiny components and back to the chosen finish as they pass from busy machine to machine. Suffice it to say that here is an enterprise full of ideas.
When you hear that they make two types of kart 100-c.c. engine (53 mm stroke and square 50 by 50 mm. for that 100 cc.), and disc brakes in steel for competition motorcycles, as well as the 18 in. diameter bike wheels that may well be employed on the Suzuki works bikes next year, plus any number of special car wheels -in addition to their “normal” range, it pushes home the point about the effectiveness of small business. – J.W.
MATTERS of MOMENT, December 1999
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