Memorable Motorcycle: Davies 500 Honda 4

December 20, 2012
Frank Melling
Frank Melling
Contributing Editor| Articles|RSS

Our Memorable Motorcycles expert, Frank Melling also is the organizer of the British vintage motorcycle extravaganza known as Thundersprint. Melling began riding five decades ago and remains as much in love with motorcycles as when he drove his first bike into a cow shed wall aged ten. In the last 50 years, Melling has competed in every form of motorcycle sport and now declares himself to be too old to grow up and be sensible.

John Davies and his nephew  Colin  built this impeccable Davies Honda 4.
John Davies and his nephew, Colin, built this impeccable $33,000 Davies Honda 4 classic racing motorcycle and painted it to reflect the heritage of the HRC GP bikes of old.

Writing for MCUSA is a huge honor, and a privilege. 99.999% of the time I love every assignment but there are occasions when a real job, in a warm dry office, looks attractive.

The good news was that the rain had stopped – only to be replaced by a thick mist being blown in off the Irish Sea. Sheltering in the lee of the pit wall, I stood in my race leathers shivering, miserable and wondering whether riding a race bike in November was anything less than a totally stupid idea.

What raised my spirits was the utterly beautiful Honda being backed onto the starting rollers. From every angle, creator John Davies and his nephew Colin, who actually built the bike, have produced a motorcycle of grace and elegance – from the detailed work on the carbon fiber rev counter bracket to the sinuous, not to say sensual, curves of the four megaphones thrusting their way from beneath the engine to the rear wheel. From every angle, in every respect, this is a stunning motorcycle – truly catch-your-breath beautiful.

Even so, as the wind picked up and the mist thickened to drizzle, I would have much preferred to be looking at this motorcycle art inside a heated motorcycle show hall: then the starting roller spun.

At first, the Honda didn’t quite catch – no doubt because it had the same view of the weather as I did. Initially, there were three or four coughs and then a half sneeze as first one cylinder fired closely followed by its sister and finally, the spine tingling, staccato rasp of classic racing four in all its glory. Suddenly, riding in the cold and wet seemed like the best idea in the world.

The grace and elegance of the Davies Honda 4 took our man Mellings breath away.
The grace and elegance of the Davies Honda 4 took our man Melling’s breath away as he considers the pros and cons of a modified home mortgage. We say relax Frank, enjoy the ride.

So how was this wonderful motorcycle born? You have to look at the rather esoteric regulations which surround classic motorcycle racing. Boiled down to their core, four-stroke motorcycles made before 1973 are eligible for Period 1 and 2 racing. These bikes need to have engines which look the same as the original machines externally and must have the same frame geometry. However, what goes on the inside can, and is very different.

John Davies is many things. A competent racer in his younger days John is first, last and middle a hard core bike fan. He is also a good ol’ boy; a wheeler dealer having sold cars, furniture, pubs and now racing motorcycles. He explained the philosophy behind the Honda 4.

“Two years ago, I was at the Manx GP – soaking up the nostalgia and dreaming about the golden days of Honda 4s and Hailwood battling it out with Ago on the MV.

“I sat at the 13th milestone, listening to the Paton Twin on full song and a bit later there was Dave Kay’s MV3 replica. They are both fantastic bikes and the wail of these multis got the hairs on the back of my neck standing up.

“A bit later, we were in the pub, talking about the Paton and MV and saying what fantastic bikes they were. The problem with both of them was the price. The Paton was weighing in at around £77,000 ($115,000+) and the MV was going to cost in the region of £150,000 with tax ($180,000).

“Almost as bad is that the parts needed to run them are based on a percentage of the original cost of the bike – and that is horrendous.

“Even a good Matchless G.50 or Manx Norton is over £38,000 ($45,000) and a really quick one even more expensive than this.

“I couldn’t see any sense in these prices – but I did want a multi of my own!

Davies builds his own frames from Reynolds 631 tubing following the TAB design approved for classic racing.
The Reynolds 631 tube frame conforms to the TAB design approved for classic racing and helps incorporate modern technology and materials to an old-school design.

“We already had experience in building fast 350s based on Honda’s K4 engine. We also had a try with the 500 Honda Twin engine and we got this to give 60 hp at the back wheel – but at a huge cost to my wallet and my nerves. Believe me, 60 hp is the end of that Honda’s performance!

“What we wanted was an engine with the potential to make good power but still be completely reliable. The 450/500 Honda engines had finished us forever with quick bikes that were always blowing up.

“We were already making our own frames from Reynolds 631 tubing following the TAB design which was approved for classic racing.

“The reason we started building our own frames was simple. Every one of the TAB frames we ordered from outside suppliers was different. It was mad. We just couldn’t sell frames like this to customers where nothing fitted and every bike handled differently.

“In fact, this is the same reason we make, and control, so much of the products we sell. We want to supply classic racing products to the same standard as everything on sale today. You don’t expect to have to file your fridge door so that it will close or weld a bit on your TV to be able to watch it. Why should classic racing parts be any different?

“After a lot of discussion with the CRMC, (Classic Racing Motorcycle Club) who effectively set the eligibility standards for classic racing bikes world-wide, it was agreed that we could use the single overhead cam, CB500 four engine from 1972.

“The engine had to remain the same externally and the frame geometry also had to be identical to the original road bike but we could do what everyone else in classic racing does; modernize the engine internals and use modern materials for the frame.”

The bike steers beautifully and the handling is rock steady and very confidence inspiring.
The trick retro-Honda steers beautifully and the handling is rock steady and confidence inspiring despite the treacherous weather conditions facing us at the famed Anglesey Circuit

At this point, you would forgive John and Colin if they had produced a neat, workmanlike race bike like the many excellent Honda K4-based machines which are in action every weekend. Instead, the Davies Honda looks every inch like a GP bike but still stays within the regulations – albeit only just.

Starting with the engine, the original Honda cylinder barrels, cylinder heads, and some of the minor castings are retained. The crank is Honda too but much lightened. Of this, more later.

Inside the motor go bigger valves, with thinner 5mm stems for added reliability, lightweight slipper pistons and a Nova, six speed, close ratio gearbox. A Davies Motorsport cam opens the valves and the standard-style In-Line Four-cylinder clutch has Kevlar plates. The finished motor is not only fast but very user friendly as well. Maximum power is produced at 10,400 rpm but there is plenty of racing power all the way from 7000 rpm. The motor will also rev on a further 1000 rpm with safety.

Compare this with a G.50 which makes very little power until 6500 rpm, peaks at 8000 rpm – and is getting very tense indeed at 8500 rpm. In short, the Davies Honda is a dream for riders of all abilities.

John uses his own electronic ignition and the engine is fed by 26mm Keihin racing carburetors.

The frame is just as carefully executed and again takes the regulations right up to the last letter of the law – but doesn’t quite break them.

The Davies Honda 4 has an upgraded swingarm  a handcrafted aluminum fuel tank  and fiberglass frame  all barely within classic racing regulation.
The Davies Honda 4 has an upgraded swingarm, a handcrafted aluminum fuel tank, and fiberglass fairing, all barely within classic racing regulation.

The Davies frames are made from Reynolds 631 steel – the son of the legendary Reynolds 531 used in Manx, G.50 and a host of other classic racing designs. 631 has the advantage of being tolerant of TIG welding and when the weld is cooled the area air hardens. The craftsmanship is sublime and anyone with a love of race bikes would want one of these frames on the lounge wall as a piece of sculpture.

Classic racing regulations permit the use of an upgraded swinging arm so John’s Honda has an oval design – but of the same length as the original Honda part.

The aluminium fuel tank is another example of old fashioned English craft skills. When John’s tank maker isn’t producing parts for him he is making alloy body shells for Ford GT40s – still using a highly skilled eye and the English Wheel for shaping the metal.

The rest of the bike continues with the art-meets-engineering theme. The triple clamps are machined from billet and titanium fasteners are everywhere. Even the rev counter bracket is fabricated in carbon fiber – hardly essential weight saving but a lovely touch.

Interestingly, the fairing is made from glass fiber. John explains: “It’s no problem to make the fairing in carbon fiber but the added cost is huge. Also, glass fiber is easy to repair in the paddock whereas carbon fiber is much more complicated.

“We’re not interested in racing a one-off Davies Motorsport special. Everything on our bikes is for sale – and right off the shelf. No waiting or messing about. If a bit is on our bike you can buy it. In fact, you can buy this complete bike now!”

Not only are there lovely cosmetic touches everywhere on the bike but the engineering is sound. The Honda front fork looks standard but contains the Davies cartridge conversion and the rear shocks, fully adjustable for compress and re-bound damping, are made to Davies Motorsport specification and sold exclusively by them.

The front brake is state of the art for a classic race machine with Davies’ own disc being gripped by a magnesium Lockheed racing calliper.

The rear hub on the Davies Honda 4 is tiny.
The rear hub on the Davies Honda 4 is tiny but necessary to comply with classic bike racing regulations that require all bikes to be equipped with two working brakes.

Only the rear hub is marginal in my opinion. A tiny 5” hub, from a Honda SL, machined to weigh almost nothing, is there to meet race regulations which demand two working brakes. I do like to use the rear brake to steady the bike so looked at the SL hub with a degree of skepticism.

There is a feel to a thoroughbred race bike which is difficult to articulate and which can’t be faked. The eagerness of the motor, the feather-light clutch and sweet, accurate gearbox as first gear was engaged all showed that the Davies Honda was the real thing.

Classic racing “fours” can be a real handful in slippery conditions and the Anglesey track had all the adhesion of an eel’s bottom, being wet from the mist and drizzle and still a bit grubby from a car rally held a few days before our test.

The motor was eager to rev but was so controllable. From around 5000 rpm the power just kept coming relentlessly and by 7000 revs it could have been raced. However, above 9000 was where the action was at its best.

At these revs the motor spun up so effortlessly that the LED “red light” gear indicator was a very useful tool. This was set at 10,400 rpm so changes were made at probably 10,700 rpm or so, the extra 300 revs being the time it took for a quick prod down on the left-hand side, race pattern gear lever.

This motor produces a consistent, dyno accurate, 68 bhp at the back wheel and the Honda will quite simply destroy a Manx or G.50. Not only does the Honda make a lot more power, the urge is far more available, and useable, than with a classic British GP bike. Truly, the story of 1960s motorcycle racing written all over again.

I am normally hard on the brakes but I have to confess that conditions just did not encourage charging into corners. One of the great truisms of testing someone else’s race bike is that they never congratulate you on parking the machine upside down in the Armco – never!

In these conditions, the front disc provided a surplus of braking without any need to resort to the tiny rear brake.
In some ways, the handling is even more impressive than the engine. The Davies Honda feels more like a Seeley than a G.50 or Manx Norton. The bike steers beautifully and the handling is rock steady and very confidence inspiring. The bike tips into corners effortlessly yet when the front end started to slide nothing dramatic happened.

Dont lay this one down  or itll cost you close to  33 000 dollars.
Don’t toss this work of rolling art down the tarmac or it’ll cost you close to $33,000. Check out Melling as he cooly navigates the Anglesey race course. As classic racing motorcycles go, it doesn’t get much better than this.

All too often with a classic race bike, if the bike is set up for quick steering then it becomes nervous and, for a second rate rider like me, disconcerting. I need a motorcycle which is 100% on my side when I am racing and one which will cover my mistakes rather than punishing me. The Davies Honda is solid gold in all these respects.

This brings us to the punch-line: cost. However, first a statement of intent from John. Given fresh, synthetic race oil every time the bike is run, John fully expects the bike to do a full season’s racing without any work – crash damage apart. So, running costs are affordable by the club racer.

John will also sell you absolutely anything from the actual bike we tested, or you can have an exact nut and bolt replica of it for around $33,000 – depending on the pound sterling/dollar conversation rate at the time of purchase.
A basic bike starts at just $24,000 and you can go racing with this.

If the Davies Honda were a converted road bike even $24,000 would be expensive – but it isn’t. For your money, you get a real racing motorcycle with all the style and attention to detail of a thoroughbred. Just as important, the bike feels every inch a pedigree motorcycle and I have rarely been so satisfied after a test.

And here’s the real clincher. Except for the fact that we have so much money tied up in our own G.50 I would be first in the queue for the Davies Honda – it’s that good.

By way of a postscript, there has been an interesting development since I rode the bike. There has been a huge amount of interest in John’s 500 from racers – but almost as much interest from road riders wanting a really tasty Café Racer. The next project from the Davies workshop will be a road legal Café Racer – light, beautiful and with 120 mph performance. Start saving up.

You can contact John at

Our thanks to the Anglesey race circuit for the use of their great track which is fun even in November!