Today I am going to explore the thrilling era of the 1960’s and 70’s. Seeking out the adrenaline-fuelled world of the fastest 500cc motorcycles. There’s a bit of background from the post war period too.
From iconic legends to hidden gems, join us as we unveil some true champions and step into a past, where speed was king and these bikes ruled the roads.
We have looked at the 250cc motorcycles that broke the 100 mph barrier in a previous video and today I’m going to look at the 500cc motorcycles that came before them.
I hope at least some of them manage to surprise you, and I am sure you will tell me about the bikes I have missed. There is always at least one or two.
As with the 250s I have tried to stick to production motorcycles and out of the showroom speeds, but you have to remember it was a very different world. I cant vouch for the accuracy of any factory quoted figures and remember, there is always a trade off between acceleration and top speed.
There is an interesting article about understanding motorcycle gear ratios on the website that I will link in the description below for anyone that is interested, but stick around for now. There is plenty to come.
Some of the motorcycles in the list were known more for their potential, rather than for the standard power figures. Engine and chassis specialists popped up everywhere. People like Harry Weslake who invented the process of gas flowing heads, and Colin Seeley who built frames that were so much better than anything the large manufacturers were churning out it was like they were from a another planet.
I have been planning a video about some of these forgotten heroes of the motorcycle industry but you can imagine that is a long term project.
As always there are bound to be motorcycles I miss, and I look forward to you telling me all about them. This one was a bit of a minefield with contradictory information and exaggerated claims. I do think some of the manufacturers claims were maybe fuelled by the strength of the illicit substances available during this era.
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The Post War Period
Now to give the motorcycles of the 60’s and 70’s some context I have to mention a few earlier bikes first, These were the benchmarks that had been set in the period after the second world war. These first motorcycles were still being made in the 60’s, but had been designed and first built in some cases long before then.
The first bike I will mention is a legendary motorcycle and is also the oldest. Made by one the companies with a long and successful racing history going right back to 1909.
AJS Porcupine
AJS was a family company named after Albert John Stevens. They had their first TT win in 1914, taking first, second, third, fourth and sixth places. That is even beyond the dominance Ducati have managed in the 2023 MotoGP World Championship and World Superbikes.
With interruptions during both world wars the company never had an easy life, but after the second world war they began work on an all new motorcycle that was to be supercharged and entered into the world championship. Unfortunately for AJS the rules were changed to ban superchargers, and the motorcycle had to be reworked to make it eligible to compete.
The result was the AJS E90 Porcupine, This is the original horizontal twin design where the engine had been laid flat so there was space for the supercharger above. This radical design was reworked to produce over 40 HP @ 7800 rpm, in the 1940’s.
Les Graham won the 1949 World Championship on an un-supercharged AJS E90 500 Porcupine, but for 1954 the bike was developed further, lowering the engine in the frame, and raising the power to 48HP. It immediately won the first two rounds of the World Championship and took first at the Isle of Man TT
The bike was clocked at 135mph, but putting that into perspective, it was not renowned for its acceleration. However, it holds the title of being the only twin cylinder motorcycle to ever win the Isle of Man TT Senior race and it still holds that honour to this day.
These were motorcycles tuned for racing, so it wouldn’t be fair to compare them to the other bikes on this list, but it will give you an idea how far ahead of the game AJS were when I talk about the other fast 500cc motorcycles of this post war period and beyond.
It dint stop there either. By 1953 AJS were already reworking the Porcupine, and the original horizontally laid cylinders were moved to make a 45 degree angle parallel-twin. This motorcycle was given the name of the E95 Porcupine and although very different, it used much of the technology that had made the original E90 so fast. The E95 was tested at 55HP in 1953, but they were unreliable on track and sadly, only 4 were ever made as far as I am aware.
Associated Motorcycles and the AJS name eventually ended up in the hands of the Norton-Villiers group in 1966. The factory was turned over to making the then new Villiers Starmaker engines, and AJS faded away from the racing world.
I will also give a brief mention to the now legendary 5TA. It did only produce around 27HP standard, but it changed the focus of the British motorcycle industry going forward. Edward Turner will have seen the success of the AJS twins, but he would bring a cheap and powerful twin cylinder engine to the masses.
Velocette Venom
The next motorcycles that need to be mentioned are the 1955 Velocette Venom and the 1956 Norton Dominator. These were both 500cc motorcycles that could not only break the 100mph mark but hold that speed.
The Velocette Venom was an expensive hand made 500cc single that produced around 34HP and weighed around 175kg dry. It has the honour of being the first motorcycle to average over 100 mph continuously for 24 hours. No 500cc single-cylinder motorcycle has broken that record to this day as far as I am aware.
Norton Dominator
The Norton Dominator was an attempt to build a motorcycle that was better than the Triumph 5TA Speed Twin. Bert Hopwood had been on Edward Turner’s design team at Triumph and when he moved to Norton a new Twin was designed to try and win back some of the market the Speed Twin had taken from them.
Later models would be increased to 650cc, but the first 500cc twins produced 31HP and weighed around 180kg dry and would easily hold speeds of 100mph. They were smoother and easier to start than the big singles and along with the 5TA and the various BSA twins would set the path of the British motorcycle industry going forward.
BSA Gold Star
I have to mention BSA here too, They had been building the 500CC single-cylinder BSA Gold Star since 1938 and it was a real winner. By the 60’s it was producing 48HP and 38Nm of torque and weighed 172kg dry, giving it an incredible top speed of over 110 mph. It continued in production until 1968. Built for speed alone, the 500cc single was notoriously hard to start and ran like a two-legged camel at low revs, but get it on a track and it was a different story.
Matchles G85 CS
One last mention before we start the main list is for the Matchles G85 CS. AJS had become part of the Associated Motorcycles group and Matchless were their bread and butter brand. Matchless used the latest AJS engine in the G85 CS which was a thoroughbred Scrambler. It was built in 1964 and produced 41HP and 43Nm of torque and weighed in at just 145kg dry. If it had been geared for top speed who knows how fast it would have gone, but it was geared low for competition Scrambles, so top speed is not a fair way to judge it, but it does deserve a mention.
The 1960s
Now we come to the 1960’s and the start of the list proper and it is another list that has to be done in date order for it to make sense.
Honda CB450 Black Bomber
Into the market I have described above, in 1965 Honda released the CB450 Black Bomber. The CB72 250cc Dream Twin had been a huge success and Honda wanted some of the Large Capacity market dominated by the British twins and singles. The Black Bomber did compete on performance with many of the bigger bikes on the market. It produced 45HP and 37Nm of torque and weighed about 185Kg dry. This gave it a top speed in excess of 103mph.
The CB 450 wasn’t a cheap motorcycle though. The engine was a double overhead camshaft design and it had a 180 degree firing order. Both of these elements made it appear new, different and exotic, but it wasn’t the commercial success that the CB250 was. It just didn’t offer any significant gains in performance over some of the motorcycles already established in the world markets. What it did do, is make other manufacturers take notice of this company that were still newcomers on the world stage.
Velocette Venom Thruxton
Next, also in 1965, we have to revisit the Velocette Venom, because we got the release of the Velocette Venom Thruxton, The fastest incarnation of the Venom models. Power had been pushed up to 41HP, but it was the 48Nm of torque that made this big single such a success. Weight was around 170kg dry and geared for speed it was clocked at over 120mph giving it performance that would not be equalled for years.
It regularly outperformed bigger bikes and was renowned for the beautiful build quality that made Velocette their name, but it was another expensive motorcycle, so was out of the reach of the average working man.
It does also show that out and out top speed is not always the best way to compare motorcycles. Yes the Venom Thruxton was a fast motorcycle. Outside of the AJS Porcupine, probably the fastest 500cc motorcycle of its day. However, That speed was achieved on a motorcycle geared for speed. That came at the cost of acceleration, despite the impressive torque figure.
In the hands of a racer who could hold their speed through corners and take advantage of the long gearing it was a world beater, but it was one of those motorcycles that took a special breed of rider to get the most out of it.
Triumph T100 Daytona
Next in 1967 we have the Triumph T100 Daytona. Buddy Elmore had taken a works Triumph Tiger to victory at Daytona in 1966 and never a company to miss an opportunity, Triumph developed an all new High Performance Tiger to try and help it carve out a piece of the huge American market. So the Tiger T100 Daytona was born. It produced 41HP and 38Nm of torque and weighed in at just 160kg. This meant it could hit a top speed of 105mph.
It did it relatively cheaply too. This was the motorcycle that dragged the ageing Triumph Speed Twin into the firefight that was the 60’s quest for more speed. The mass produced Triumph’s just didn’t have the same price tag as the hand built Velocette’s. They were easier to live with than the highly tuned big singles too. Looking back, the Daytona has a timeless design that is still being copied today. It doesn’t look at all dated when compared to many modern bikes and when compared to the bikes of its day it was treading fresh new ground.
Suzuki T500 Titan
In 1968, a new contender hit the market. Two Stroke power had begun to dominate racing and the Japanese were bringing it to market. Suzuki had the benefit of all the parts and plans that had been stolen from MZ by Ernst Degner, and in 1968 they unveiled the all new Suzuki T500 Titan, an air cooled vertical twin-cylinder two-stroke that would again change the focus of the industry.
The T500 produced around 45HP and about 50Nm of torque. It weighed 185Kg but still had a top speed of 115mph straight out of the showroom. Compared to the Daytona or indeed most bikes of the time this was a seriously fast motorcycle. The engine formed the base for many race bike builds and it was the forerunner of all the great GT range of two-stroke Suzuki’s that would follow.
The torque of the original engine put all of the other bikes on the market to shame. There really was nothing that could compete. It was simple to work on and tune too. Less parts also meant cheaper manufacturing, so even with the import tariffs it was a cheap and well built motorcycle that began to solidify Suzuki’s place in the market.
Kawasaki H1 Mach 111
Next we have a motorcycle that you will all recognise, As much as the T500 had begun the reshape the industry, this motorcycle would just smash all the moulds. It was the Kawasaki H1 Mach 111, a 500cc two-stroke triple designed to be the fastest motorcycle on the market.
As you all told me this motorcycle should have probably featured in the Dangerous Motorcycles video which I will link above.
Kawasaki knew that Honda had something big coming. They almost certainly knew some of the details of the CB750 project. They had their own big four stroke in the pipeline, but the Z900 wasn’t going to be ready.
In the background a project had been planned and they had been experimenting with in line and L-triples. They decided on a in line 3-cylinder two-stroke and were determined to make it the most powerful production bike available to steal Honda’s thunder.
As such, shortly after the release of the CB750, the first Kawasaki H1 Mach 111 rolled into dealerships. The CB750 was big, powerful, comfortable and refined, The Kawasaki was only one of those things, it was built for one purpose, speed.
It quickly established itself as the top dog when it came to speed. The engine produced around 60HP standard and torque was around the 55Nm mark, so it was significantly more powerful than the Suzuki T500, but all the power was produced in a really narrow rev range that meant the throttle had only two settings. All, or nothing.
The design had been thrown together in a total of just 14 months, which meant very little research and no development had been done. The chassis was poor, the suspension had the stiffness of cooked spaghetti and the brakes might as well not have existed, but customers didn’t care. They wanted the power, whatever the consequences were. Whatever drawbacks the final motorcycle had.
With a weight of just 175Kg dry, the monster of an engine could propel this motorcycle to the end of a quarter mile strip in just over 12 seconds and could take it up to a claimed top speed of 124mph. Just to note, the Honda CB750 had a claimed top speed of 123.6mph, so the 124mph claimed speed of the Kawasaki was very convenient. The reality is both were fairly hopeful for a showroom bike, but the two-stroke tuners would make sure that the H1 was always first in the queue at the drag strip.
The bike was raw, noisy, smelly, uneconomical and dangerous to ride, and customers loved them. With the possible exception of the AJS Porcupine, this was the fastest 500cc motorcycle ever put into production. It would retain that title right through the 1970’s and much of the 1980’s.
The 1970’s
Honda CB500 Four
From the ridiculous to the sublime, in 1971, Honda released the CB500 Four. As its name suggests it was the smaller across the frame four that Honda had built to complement the success of the CB750. The CB500 wasn’t quite as powerful as its big brother, producing 50HP and 45Nm of torque, but at 200kg, it was almost 25kg or 50lbs lighter.
It had the comfortable refinement of the CB750, but handled better, was more flickable, and had a creditable top speed of around 115mph. It might not have been a H1, but it was the fastest four-stroke 500cc motorcycle of its day and the single cam engine was a delight to ride and totally indestructible.
To put into perspective how good this motorcycle was, in 1973 it was entered into the 500cc production class at the Isle of Man TT and it won. Bill Smith was the rider who brought it home first, over 8 seconds ahead of the great Stan Woods on a Suzuki T500. I guess Kawasaki didn’t get the memo.
Yamaha TX500
1973 saw Yamaha fight back with an all new four-stroke parallel twin, the double overhead cam Yamaha TX500. Producing 48HP and 44Nm of torque it was almost a match for the Honda Four, but even with a lighter weight of 195Kg it just never managed to better the Honda. With a top speed of around 110mph it certainly couldn’t match the T500 or H1.
Despite that, it was a great bike, and would form the soul of the iconic XS650 that followed soon afterwards, yet somehow it seems to be overlooked and overshadowed by the later 650 that may never have existed without the TX500.
Three more years passed with nothing significant coming to market to challenge the H1 as the fastest two-stroke 500 or the CB500 as the fastest four-stroke of the 70’s, yes I know I have already told you the Velocette Venom Thruxton and the AJS E90 were faster, but for now I am using the CB500 as the new benchmark for the 70’s.
Yamaha RD400
Then, in 1976 we had three new and very different contenders. The first was the smallest, and least powerful, it wasn’t as fast as the H1 or the T500 either.
So what made it so great you felt you had to include it? I hear you say. Well two simple letters should explain that. It was an RD. The new Yamaha RD400 produced around 44HP and about 40Nm of torque but it weighed just 165Kg dry, 35KG or over 75lbs less than the TX500 or CB500 Four.
Top speed of the RD 400 was no more impressive with about 108mph standard, so again it wasn’t a winner in that department, but it handled really well and the lighter weight made it a fantastic package and exciting to ride. Wheelies had never been so easy. Whatever it was that all the early RD’s had, the RD400 had it by the bucket load.
Stood in a crowd of bigger, more expensive bikes it was still the RD’s that got the biggest audience.
They had their haters for sure, but many more people loved them. Specialist tuning shops could make them faster too, and it was a lot easier to make the RD400 faster than it was to make the bigger heavier bikes lighter. These things together, meant that in the right hands, the RD would often have the edge in the real world. Whatever bikes were chasing.
The RD400 was a real giant killer in a way few bikes have managed to be over the years. The Cagiva Mito is probably the next on that particular list so the RD is already in fabled company, but that as they say, is a story for another day.
Ducati 500 Sport Desmo
The next motorcycle that landed in 1976 was the Ducati 500 Sport Desmo and this is one of those motorcycles that really does split opinions. It split opinions in the factory too. Half of the staff at Ducati never wanted to build it, as they had become known for the big V-twin bevel drive engines used in the 900SS and 860GTE.
The 500 Sport Desmo was to be a parallel-twin, and despite having never made a parallel-twin before, Ducati built a great motorcycle. It was as powerful as the Honda Four, but it was lighter too. It produced 50HP and around 42Nm of torque, but the twin weighed less than the Honda at 185Kg. Top speed was around the same 115mph mark but the Ducati pulled better with a consistently better ¼ mile time.
However, it had another Italian to contend with, that was following in it’s footsteps.
Benelli 500 Quattro
That motorcycle was the Benelli 500 Quattro. Benelli had very definitely NOT purchased a Honda CB500 Four and then deconstructed it when designing the 750 Sei, they said so. The 500 Quattro was effectively two thirds of the 750 Sei six cylinder engine and was almost identical to the Honda engine. It was smooth and powerful and a rival for the Honda at everything except what Honda do best, consistent reliability.
The Benelli 500 Quattro produced around the same 50HP as the CB500, had a claimed torque figure of just over 40Nm and a asimilar weight to the Ducati at 185Kg. From that, they claimed a top speed of 118mph which was slightly faster than both the Honda and Ducati, at least according to the manufacturers it was.
Remember, this was a motorcycle built when the Italian Industry was fighting for survival and despite the genuine quality of the build in general, there were inconsistencies and reliability issues.
Jumping three years again we come to 1979. I guess things ran in 3 year cycles then.
This brings me to the last motorcycle on the list proper today, although there is one more honourable mention. I will look at the 500cc bikes of the 80’s and 90’s in a future video.
This motorcycle was fast, Italian, and the last roll of the dice for the company concerned. The Italian economy was dying and taking the motorcycle industry with it. The 500 Sport Desmo wasn’t the sales success Ducati had hoped for and they needed a mid sized motorcycle they could offer at a good price. Shrinking down the by then legendary 900SS engine should always have been the obvious choice.
Ducati 500SL Pantah
When they did, the motorcycle that was released was the Ducati 500SL Pantah. This marked the direction that Fabio Taglioni would take the next generation of Ducati engines in, and it has influenced every Ducati engine built since.
They kept the now ubiquitous Desmo valve actuators, but replaced the bevel drive cams with a toothed belt drive.
It wasn’t the sort of minimal sports bike Ducati had been famous for either. This was a more refined ride. The trellis frame handled beautifully and the smooth engine made it a pleasure to ride when compared to the more common parallel-twins of the time.
Power wasn’t electrifying at just 45HP but it was the low down torque and delectable soundtrack that always made this bike seem fast. The official torque figure was 45Nm and the bike weighed around 180Kg dry, but Ducati claimed a top speed of 121mph, making it in theory the second fastest 500cc motorcycle on the market after the Kawasaki H1.
I am not sure how accurate that figure was, as we know that the factories always stretch the truth, but it was a capable GT bike despite being just 500cc and it was no slouch.
Laverda 500 Montjuic
Finally I am going to give one more motorcycle an honorary mention, I featured the Laverda 500 Montjuic in another video which should be linked above, So I wont include it here. It wasn’t the fastest of the 500s, but producing around 58HP in standard trim it was a four-stroke twin that was almost as powerful as the Kawasaki H1 triple. Its engine would be developed even further, eventually reaching 750cc almost 3 decades later, which should give you an idea how over engineered the original design really was.
If you are interested there is some footage from me taking one of the Laverda’s with the later incarnation of this engine around Cadwell Park in the video linked above.
The Results
So, where does this leave is in the title for the fastest 500cc bikes then?
If we purely use speed we actually end up with the AJS E90 Porcupine at number 1 with a top speed of 135mph, at number 2 we have the Kawasaki H1 Mach 111 at 124mph. At number 3 we have the Ducati 650SL Pantah at 121mph, At four we have the Benelli 500 Quattro at 118mph, and we have 3 bikes tied for fifth place at 115mph, the Ducati 500 Sport Desmo, The Honda CB500 Four and the Suzuki T500 Titan.
However, if we look at power, we get a slightly different list. First we have the Kawasaki H1 at 60HP, second we have the Laverda Montjuic at 58HP, equal third at 55HP we have the AJS E95 Porcupine and the Benelli 500 Quattro, and equal fifth at 50HP we have the Honda CB500 Four and the Ducati 500 Sport Desmo.
Personally I would probably put my list closer to the 2nd power based list. What would your top 5 be?
Well, thats it for today. If you got this far I take it you’ve enjoyed this trip into the fiery and flamboyant history of 500cc motorcycles.
I have to say it was a very interesting video to make.
Some of the bikes as usual surprised me, so I hope you got a surprise or two as well.