Updated: Aug 20, 2021

Alan Cathcart was a successful international motorcycle racer from 1974 to 1999, and since those days has combined his riding skills with his writing talents to become one of the world’s most respected motorcycle journalists, especially known for his track tests of many of the world’s rarest racing motorcycles. One such machine he tested was the 500cc four-cylinder Honda ridden by the late, great Mike Hailwood in 1966 and 1967.In its day it was rated as the most fearsome motorcycle ever raced but, having also track tested all of the even-more awesome 500cc two-strokes of the 1990s, Alan was able to make some interesting and relevant comparisons between the bikes of the two eras.

He writes:

Despite the fact that they dominated the 500cc Grand Prix class with the two-stroke NSR500 for most of the 1990s decade, Honda at the time made no secret of the fact that they would have preferred to have won that particular World Championship class with a four-stroke. And they certainly devoted a massive effort to doing so for two years in the 1960s.

Although the winner of the Manufacturers’ title in 1966, the fast but flawed Honda four-cylinder RC181 never succeeded in winning the coveted Riders’ crown. It came close in 1967, thanks to the superlative riding efforts of Mike Hailwood, but the bike was not as perfectly developed as Giacomo Agostini’s MV Agusta so Mike and Honda had to give best to the Italian combination.

The RC181 had a 500cc double overhead camshaft,16-valve four-cylinder air-cooled engine that delivered 93bhp at 12,650 rpm in an era when getting 100bhp from a half-litre engine was just a tantalisingly close dream for motorcycle manufacturers. In fact, even the Formula One V8 and V12 car engines of the day could not come close to achieving that then legendary ratio of power to capacity, which would have extrapolated into 600bhp from their three litres. In those days they were still some 100bhp short of that target,

Honda motorcycles at that time had the most developed four-stroke engines in the world and the 93bhp of the RC181 made it good for an amazing top speed for the era of 172mph (276kph). However, the bike’s 141kg. dry weight combined with an imperfect frame design and the poor construction materials available back in the day meant that this much power delivered unruly handling that required constant vigilance and personal strength.

After winning four 500cc World Championships for MV Agusta between 1962 and 1965, Mike Hailwood switched to Honda to help that factory achieve its aim of winning back the World Championship from Yamaha in the ultra-competitive 250cc class at that time. In 1966 he emphatically did so with ten wins from 12 Grand Prix races. In fact, he won every race in which he finished on Honda’s legendary six-cylinder 250! Not only that, but he also won six out of 10 350cc GP races on a 297cc version of the six to take that World title as well.

It had not been intended for Mike to fully contest the 500cc class for Honda in 1966. That task had been given to the factory’s faithful servant and six-time World Champion, Jim Redman. Jim won with the bike in both the German and Dutch Grands Prix but it threw him off at the high-speed Spa Francorchamps circuit during the Belgian Grand Prix – a crash in which he suffered the serious arm injury which effectively ended his career.

And so it fell to Mike Hailwood to step in as lead rider of the RC181, a task that meant he had to ride three GP races in a single day, including the final one of the day on the relatively unfamiliar, ultra-powerful and poor handling 500cc four. He had ridden the bike in the Dutch and Belgian Grands Prix but failed to finish. There was another DNF in East Germany, but then came a win in Czechoslovakia, second place in Finland and two more wins in the Ulster GP and the Isle of Man TT. These were enough to place Mike second to MV Agusta’s Giacomo Agostini in the 1966 points standings and to secure the World Manufacturers’ Championship for Honda,

As the 1967 season began, it seemed as though it would be Hailwood and Honda’s year in the 500cc class, even though his workload would be heavy, with three classes at every Grand Prix. In the 350cc class it was generally plain sailing, with six wins out of eight races. And despite the opposing combination of the riding talents of Phil Read and Bill Ivy on the very fast vee-four Yamaha two-strokes, Mike also took the 250cc title again with five wins in a long and hard fought 13-race season. He had tied on points with Phil Read but broke the tie by virtue of one more win.

Taking into account the riding effort it took to win those 250 and 350 titles, it seemed almost too much to expect Mike to take a World Championship hat-trick with the 500cc crown as well, And so it turned out, He won five races but had to give best to Giacomo Agostini and the MV by the narrowest of margins. He and Ago tied on 46 Championship points each, with the Italian also winning five races but critically also winning the tie breaker with three second place finishes to the two scored by Mike. Evidence of just how hard-fought that season was comes from the fact that two of the three classes were decided by tie breaker rules.

At the end of the 1967 season, Honda pulled out of racing but allowed Mike to hold on to one of the 500cc fours for use in non-Championship but financially lucrative races. During that season, the bike cemented its reputation as a hard-to-handle beast when Mike lent it to the leading UK short circuit star of the time, John Cooper. After struggling with the RC181 at Oulton Park, ‘Coop’ told reporters “Only one man can ride that bike and it’s not me!”

There were two factory RC181 Honda 500 fours built in 1966. Both still survive, now back in the hands of Honda Japan; one on display in the magnificent Collection Hall at Motegi, the other in the lobby of the firm's plush Tokyo corporate HQ. But until a few years ago, one was on display in the Donington Park Museum Collection, the property of Mike Hailwood's widow Pauline. Mike had sadly died in a road accident in 1981,

After Mike's tragic death, the 500cc engine was overhauled for Stuart Graham to ride the bike in the Hailwood Day commemoration at Donington the following year. The year after that, Bill Smith had a spin on it at the track’s 50th Anniversary meeting. Then Honda Britain fettled the bike again for none other than Freddie Spencer to demonstrate it at the 1984 Transatlantic Match Races. He enjoyed the experience so much that he offered to take up classic racing if Honda would sponsor him!

Some ten years later, Honda bought the bike back from Pauline Hailwood and took it back to Japan. But before that happened, I had the thrill (and the honour) of spending half a dozen Donington laps aboard one of the most famous motorcycles the racing world has ever known. Or maybe that should be 'infamous'...

What a thrill - even if I did approach it with more than the usual amount of trepidation. After all, this was the racer that even Mike the Bike couldn't fully tame. Would it turn round and bite the likes of me?

The result was an interesting lesson in the theory of relativity, motorcycle-wise. I can say hand on heart that I rode the 500 Honda hard enough to get a pretty good idea of its true character - especially on the modern KR124 tyres fitted for this test. That was despite observing a strict 10,500rpm rev limit (1,000 revs below the red line) and having to accept that one couldn't really expect to start proving the limits of such a priceless piece of racing history, in so few laps.

But thanks to the many bumps and ripples of Donington before it was resurfaced, the track conditions simulated a typical British short circuit of the 1960s, if not the rougher, more rapid Isle of Man. Under these conditions, the Honda's handling showed itself to be far from perfect - but at the same time, it wasn't exactly the most unruly or difficult bike I've ever tested.

That's not to detract in any way from Mike Hailwood's superhuman efforts in the much longer races that he contested back in the day, and in which he battled with the world’s best after riding two equally lengthy and hard-fought GP races in the 250 and 350cc classes. And after all, he did show us on his TT comeback in the late 1970s that he was also a master of latter-day machinery, such as the Suzuki 500cc two-stroke square four with which he won the Isle of Man Senior TT in 1979. But anyone who has raced a modern 500cc GP bike - ten kilos lighter than the RC181 and with two-and-a-half times the power – has had to cope with a device at least twice as fearsome as the Hailwood Honda.

Here's where the relativity between the two eras of racing comes in - Honda-style.

Valentino Rossi's NSR500 in 2001 had a power to weight ratio of 1.52bhp per kilo: the RC181's had less than half that, at 0.66bhp/kg. No matter how great the advances in suspension, tyres and chassis over the intervening 20 years, riding the RC181 at the limit would seem matter of fact to the majority of today's GP stars. A good-handling 500GP race bike of the early years of the current millennium would shudder as you poured the power on, try to kick the back wheel out of line, paw the air like a circus pony, and use all the road in and out of corners if you hadn't set up the suspension and chassis geometry just right.

And that was on a good bike, on which you had power of control over how it did all that stuff. With an evil-handling one - and the Japanese factories could still get it spectacularly wrong - you just had to hold on tight and pray you could wrestle it into submission! I found that out when track testing Eddie Lawson's 1989 title winning NSR500, for example, which was arguably the worst handling bike ever to win a World Championship.

But, as stated, comparisons also have to be relative. In an era when 60bhp was nirvana for the rider of a Manx Norton weighing about the same as the RC181 (140kg), the Honda was a truly fearsome beast.

It required its rider to explore then-new frontiers of performance and control. Back then it was the most powerful GP motorcycle ever built, with 50% more power than its single-cylinder rivals, and a power to weight ratio that was exceptional. And as even they now admit, in those days the Japanese factories had not yet learnt the black art of frame design, and the correct use of materials. That was all to come.

My own brief encounter with the RC181 Honda was like a visit to Disneyland's Space Mountain, or one of Alton Towers' meanest thrill rides. You're sort-of disappointed you weren't more thoroughly frightened out of your skin - but you had a good time, all the same.

The bike felt good to sit on, the quite stretched-out riding position suiting my taller stature than Mike's. At the same time, I felt that the rider's weight ended up being in the wrong place: you ought to sit further forward, to get more weight on the front wheel, which could be done by shortening the large, long fuel tank.

There was no question that the Honda engine was a delight - it surprised me how flexible it was. I'd expected a bigger, lower-revving version of the 250 six I was fortunate to have ridden, on which you had to keep the engine revving hard well into the five-figure zone. If you let it drop below 9,000rpm, it'd cut out!

The RC181 had considerably more flywheel effect than the six, plus it pulled well from low down, about 5,000rpm being enough to get you off the mark. At just on 7,800 the camshafts started to do their real work, and there was a noticeable amount of extra urge above that mark. This would have given Mike a powerband of more than 4,000 revs to play with, and a key factor with the six-speed gearbox was quite wide spaces between the top three ratios, while the bottom three were more closed up, presumably in the interests of maximising acceleration. But there were gearbox problems with the bike and on Donington's bumps and scarface surface I could feel the Honda's transmission snatching as the rear wheel skipped over the rough sections.

According to Honda’s chief mechanic, Nobby Clark, these were the result of Mike using a lot of engine braking to help slow such a fast and relatively heavy bike. "Plus, there'd be a lot of chain snatch because the swingarm pivot was too far away from the gearbox sprocket," he said, "and this would compound the problems of the reverse loadings. We had lots of trouble with the drive chain because of this: I don't know how Mike finished the 1966 TT, because the chain was totally knackered at the end, and should by rights have broken long before the end of the race."

The Showa front forks felt relatively responsive during my test, especially under hard braking where, unlike many older telescopic forks, they didn't freeze up. By contrast, the rear end felt much too stiff. Maybe the rear shocks were just too ancient and/or worn out, though there was no sign of chatter at either end. And even under reasonably spirited cornering on the modern tyres, I could feel the Honda squat slightly at the rear as I turned on the power exiting Redgate or Starkeys, indicating at least some compliance from the rear suspension.

But here the first real signs of misbehaviour became apparent, the Honda shaking its head fiercely as I exited the turn, power turned on while still leaned over. It then began a slow but relentless, insidious weave as I accelerated off down the straight. OK, Mike - I get the picture now. This was a bike which became inherently unstable with the power hard on that refused to track straight towards the point you were aiming for.

So you had a choice. You could wrestle it back on line with the power still hard on - in which case you'd end up with the blistered hands that became all part of life's rich passion for Mike the Bike during the 1966/67 seasons. Or you back off and let it recover, as I did, in which case you lose time, the race, the title, everything....

This means the most noticeable aspect of riding the Honda was the sheer amount of energy - perhaps better termed 'rider input' - that was needed in order to ride it at any speed. You had to constantly stay on top of the Honda the whole time - you couldn’t relax for an instant. If you did, it would start understeering and push the front end towards the outside of the corner - and at somewhere like Donington’s Craner Curves, that's a recipe for disaster.

Changing direction there from one side to another, and again going up the hill to McLeans, required a lot of physical effort, allied with a firm judgment, and I think it's this, which basically wore Mike out riding the bike.

By his own admission, he never did any training to get in shape for racing in those days, relying on the fact of racing so many bikes so often to keep fit. Taking into account the much longer GP races in those days, the RC181 must have been an exhausting bike to ride simply because of the length of time you'd physically have had to wrestle it around from one corner to another. And Mike wouldn't have got a lot of help from the conservative steering geometry and primitive suspension, either. Moreover, with the last race of the day at any Grand Prix being the premier 500cc class, he would have had to race the worst handling bike of his trio of Hondas after already being tired from two previous tough races.

A modern 500 GP rider has an intensive physical exercise programme, which is compulsory if you want to control the rocketships that are today's 200bhp racers. I wonder whether if Mike had adopted a similar policy, especially with the two or three 100-mile-plus GPs he'd reckon on contesting in a single gruelling day, he'd have found the RC181 quite such a handful to ride? We shall never know.

Riding the Hailwood Honda enabled me to explore the mythology of one of the most controversial racers the world has ever seen. Within the context of its age and generation, I can see how its reputation as an evil handler can have been well founded. This wasn't from any one basic fault, but rather from the overall demands its performance made on the rider, allied with the level of tyre and suspension development 55 years ago. As it was, Honda had to wait another 15 years to secure their covered Rider's world title. And it took another riding genius to do it for them: Fast Freddie Spencer on the Honda NSR500 that also had more than its fair share of handling problems.

Some things never change!

Read the full story of the Honda 500 four in the e-book published by