AYK off-road buggies (the early years 1981-1986)

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This is not a webshop, and beside what’s listed under the “FOR SALE” tab in the menu, nothing presented here is for sale, so please don’t ask. If I have anything I would like to sell, I’ll post it in the “FOR SALE” section.

Isao Aoyagi, the former President of Aoyagi Metals Co (AYK).

AYK is one of those old brands I always heard about as a kid, but never saw anything of, as they were never sold by the local hobby shops where I live. I first heard of them while reading an article about the Norwegian Nationals, back in 1982. In the list of results from that event, there was a new name appearing between the hoards of Tamiya SRB entries, the AYK 566B Super Trail! I’ve had a soft spot for that brand, from that time on, even if my obsession was the CRP/Tamiya “Superbuggy” that won the race. It should go almost 30 years before I got my first AYK, and even saw one. The one I got was, of course, a 566B Super Trail Baja Bison, the one I remembered from that article in 1982. Later I also got a 566B Super Trail American Pick Up, a Buffalo, a Bobcat, a Boxer and a Sidewinder. I don’t have any of the 4WD AYK’s, and probably never will. That could change if I find a Viper or Viper Shuttle, but they don’t show up often at prices that could be described as “sane”.


Results from the 1982 Norwegian off-road Nationals.


For my old website I was allowed by Alex of InetRC.com to use his brilliant history of AYK, and I’ll use some of his work and pictures here in this article, as well. You can visit his original AYK History site here, where he also covers the AYK on-road cars, in addition to the off-roaders I’m focusing on here. Most of the other pictures are my own, or scanned from various magazines and books, but some I’ve found online. As I’ve collected RC pictures since the beginning of time, I do not know the origins of all the pictures I have. If any of the pictures should happen to belong to you, I hope you will bear over with me, but please contact me and I’ll credit you under the picture. If you want me to take it down, I’ll do that.

The Aoyagi Metals Company (AYK) was one of the more innovative RC manufacturers between 1979 and the mid 1980’s, but they started out as early as 1953 by making railway models, and in the 1960’s they moved on to making chassis’ for slot car racing. The move from railway models to cars was due to their second generation president, the late Isao Aoyagi, being a car addict. AYK on-road RC cars dominated the Japanese race circuits and captured consecutive world championships in their peak from 1980 to 1982. Even though many of the on-road RC cars of this era looked the same, subtle differences in design specifications set each other apart. AYK, for example, had a creative differential design. Most manufacturers of this era placed their differential gears between the right rear wheel and the motor compartment. AYK’s unique design placed the differential within the axle itself. This not only centered the weight more proportionately, but also kept the differential gears well protected.


AYK’s unique differential axle.


AYK was also the first RC car manufacturer to introduce a chassis made from fiber glass. Tatsuro Watanabe who later would move to the US and start his own brand HPI, used to work for AYK with RC car development.


AYK on-road cars.


In 1981 AYK began manufacturing off-road buggies, first 2WD and later also 4WD. From 1986 AYK started a cooperation with a California based company Race Prep, who would distribute their off-road products in the US, as well as helping out with research and development. AYK released some of their most popular and competitive buggies under Race Prep, including their very last buggy, the Radiant Pro, that was released in 1991 after AYK in Japan was closed down. The “Dunn Brothers”, Steve and Mike Dunn, were very involved in that work.

Ultimately AYK’s demise came with the death of the president of the company, Isao Aoyagi, which ultimately led to loss of direction and eventually faded into obscurity. I’m not 100% sure, but I believe this must have been around 1990.


Isao Aoyagi, the former President of Aoyagi Metals Co (AYK).


The off-road part of their operations, some of which I will focus on here, lasted from the release of the 1981 566B Super Trail, and ended with the Radiant Pro in 1991. I have always believed the 566B Super Trail to have been released in 1982 like the Kyosho Scorpion, but by studying various Japanese literature on the subject, I have concluded that it was actually released in Japan in 1981, and shown at the Nürnberg (Germany) toy fair in january/february of 1982.


AYK’s first off road buggy, the 1981 AYK 566B Super Trail Baja Bison, here shown at the Nürnberg toy fair in early 1982.


Due to the short lived off-road era of AYK, the number of models are rather limited, and the different chassis platforms are quite few. In general you can say that AYK had four different platforms for their off road buggies, three for 2WD (566B series, Sidewinder series and Buffalo series) and two for 4WD (Viper series and Radiant series). You are probably thinking something like “but that’s five, not four series, stupid!”, and you’re right, but the 4WD Viper series is a mix of the 2WD Sidewinder and the 2WD Buffalo series, and shares too many parts from those series’ to be considered a completely original platform, so my four platform statement still stands! In this article I will only cover the models from 1981 to 1986, which includes the 566B series, the Sidewinder series, the Buffalo series and the Viper series. Maybe I’ll have a go at the newer models later, but for now I know too little about them to have anything meaningful to communicate.


The 566B Super Trail series


2WD AYK 566B Super Trail Baja Bison (1981)

Reviews (PDF): Adepte (FR), Auto RCM (FR), Radio Control Model Cars (UK)

Manual (PDF): AYK 566B Super Trail, AYK 566B Super Trail (US version)


The 1981 AYK 566B Super Trail Baja Bison.


The 566B was AYK’s first venture into off-road buggies, and after having a lot of experience and success with their on-road cars, the 566B was a made as direct competitor for the Tamiya Special Racing Buggies (SRB), the Rough Rider and the Sand Scorcher. Those buggies already experienced an enormous success around the world, both on race tracks and in back yards. Not having the same world wide distribution network as Tamiya, the popularity of the model depended much on how the various national distributors handled kit and spare parts availability, as well as general service. As a result of that the popularity of the 566B varied enormously from market to market, and also influenced the popularity as a competition racing buggy in the various countries. Objectively the 566B was a worthy competitor for the Tamiya SRB’s


A box of 566B spares I got from Sweden a couple of years ago.


In a big market like the US, it was not in AYK’s favor that the distributors seemed to change with every new model AYK released. In the US this first AYK off road buggy was imported and distributed by a small Californian company called “World RC Import & Export Inc”, a company never to be heard of again. In the UK the distributor was “Langtune Racing”, in France it was “MRC”, in Germany “Multiplex” and in Norway they were represented by “LoydsToys”, the family company of the (unofficial) 1984 Off-Road World Champion Eivind Loyd Pettersen, although he mostly raced CRP/Tamiya and Kyosho for off-road himself. If you know any other national distributors of the 566B, please leave a comment down below.


A UK ad for the 566B by Langtune Racing.


A Norwegian ad for the 566B by LoydsToys.


The 566B can best be described as a cross between a Tamiya SRB and a Kyosho Scorpion, although the 566B was released before the Scorpion. I understand now where Akira Kogawa got some of his ideas for the Scorpion from, even if it’s difficult to actually tell who copied who, as the AYK was also inspired by Kyoshos earlier 1/8 engine buggies. There are however a few unique and original ideas put into the mix. The front suspension is a double trailing arm system, like on the Tamiya and some of the 1/8 scale Kyoshos, but with lay down shocks instead of the stand up shocks of the Tamiya SRB. Lay down shocks should be a kind of “trade mark” of the early AYK off-road buggies.


The 566B front suspension with dual trailing arms and laydown shocks.


The similarities to the Tamiyas do not end with the front suspension, but also extends to the tires, and even the decal set. At the rear there are trailing arms too, this time very similar to the Kyosho Scorpion rear trailing arms that the Scorpion carried on from the even earlier Kyosho Rally Sports series. Unlike at the front, the rear shocks is mounted in a standing up position. An interesting observation is that the manual shows the rear shocks to be mounted “upside down”, while the model on the box shows them the other way around. The 566B chassis consists of two parallel rails, also similar to the Scorpion and early Kyosho 1/8 buggies, but seems to be even softer than the Scorpion rails, and bends at the slightest front impact. The gear box is however a very unique design, with the motor mounted longitudinal in an inline position. Like both for the Tamiya SRB and the Kyosho Scorpion, gearing options are very limited for the 566B.


The 566B gearbox and rear trailing arms.


The electronics is mounted in a big black radio box, of much softer plastic than on the Tamiya SRB’s. The radio box is also much lighter than on the SRB. Like the Tamiya and the Kyosho (excluding the Cox version, of course), the 566B came as a kit, but some of the parts, like the gear box, was pre built. The body is lexan, and in the style of the ABS Rough Rider body. The early kits came in large boxes with blister packs, while later boxes were slightly smaller, and had all parts packed in bags.


The old and large boxes compared to the later, smaller boxes.


I mentioned earlier the similarities between the AYK 566B decals and the decals for the Tamiya SRB’s. A lot of the sponsor decals are the same, but this is to be expected as these are manufacturers of car parts, but also the racing numbers etc. were obviously copied.


The Tamiya SRB decal set above, with the AYK 566B decal sheet below it.


AYK also copied one of the “Circuit” logos from Kyosho’s Circuit Buggies. The irony of that is that Kyosho only used that term for engine powered buggies, and not for the electrics.


AYK 566B decals to the left showing the “Circuit” logo from Kyoshos engine powered buggies.


2WD AYK 566B Super Trail American Pick Up (1981)


The 1981 AYK 566B Super Trail American Pick Up.


The Pick Up version of the 566B seems to be quite rare compared to the Baja version, but the only differences from the Baja Bison are a taller body mounts, some rubber rings to hold the rear part of the body, and of course the body itself, that is based on a Ford pick up. The AYK American Pick Up has the same front wheels as the Baja version, and not “proper” truck front wheels like on the Tamiya Ford Ranger and the Cox Sidewinder trucks. It’s possible to mount a spare set of rear wheels at the front, to give it that real pick up look.


An example of a 566B American Pick Up where rear wheels have been mounted at the front.


AYK Sidewinder series


2WD AYK Sidewinder – full lexan body version (1983)

Reviews (PDF): Radio Control Car Action (US)

Manual (PDF): AYK Sidewinder, AYK Gator (US)


The full body AYK Sidewinder.


In 1983 AYK released the Sidewinder, called the Gator in the US (now represented by Circus Hobbies), to avoid confusion with the Cox Sidewinder that was released a year before.


The standard Sidewinder box and the US only Gator box by Circus Hobbies.


AYK still used mostly metal parts, but on the Sidewinder more parts were plastic and fiberglass compared to the 566B. At the front, double trailing arms were still used, but the lay downs shocks were moved more inline were they were protected by the chassis and body.


The Sidewinder front suspension.


At the rear the trailing arms were now made of plastic and, like at the front, the lay down shocks were hidden inside the body. The soft chassis rails of the 566B were changed for a flat aluminum chassis, although short rails were still used at the front, to provide the “kick up” for the front suspension. The radio box was also gone, and a fiber glass top plate was used. The direction of the motor was changed to the more conventional sideways position, and the “Padla Track”-style rear tires of the 566B were changed for “knobby”-style tires, and the wheels and tires were now interchangeable with the Kyosho Scorpion series.


The AYK sidewinder without the body.


While the 566B came as a kit, the Sidewinder came fully assembled. I always found it strange to offer hobby or competition grade RC cars pre-built, but I’m probably biased since I always liked building and modifying more than actually driving them…..


The AYK Sidewinder came pre-built, and not as a kit. You still had to mount electronics and cut/paint the body.


The Sidewinder shown at the Nürnberg toy fair in 1984.


My favorite Japanese tuners, Dyna Models in Yokohama, also made a custom Dyna Sidewinder, using the MIP transmission originally for the Tamiya SRB series.


The Dyna Sidewinder by Dyna Models.



2WD AYK Sidewinder – combined frame and lexan body version (1983)


The alternative frame body version of the AYK Sidewinder.


The Sidewinder were also sold in a version with an alternative body kit. Although the name of the car was the same, the box it came in was yellow instead of blue. The alternative body was a combined lexan and plastic frame body, as opposed to the more common full lexan body version.


Another picture of the frame body version of the Sidewinder.



AYK Viper series


The AYK Viper and Viper Shuttle 4WD buggies.


4WD AYK Viper (1985)

Reviews (PDF): Auto8 (FR), Auto RCM (FR)

Manual (PDF): AYK Viper



The Viper was AYK’s first 4WD buggy (now represented by Condor Trading Company International in the US, and by Scientific France in France), and is actually a combination of the Sidewinder and the Buffalo platforms. Both the front and the rear suspension used parts from the Sidewinder, although the front shocks were moved to another position (still lay down) to make room for the front gear box. The shocks are the same as on the Sidewinder, just gold anodizes instead of red.


The Viper shocks are the same as on the Sidewinder, only golden instead of red.


The main gear box shares a lot with the gear box of the Buffalo series, and rear to front power transmission is provided by a a chain. The chain is fully exposed, as it does not have any form of chain guides/guards, like eg. the Kyosho Optima. The aluminum chassis is a tub style, unique to this model, and is very similar to the style used on the later Kyosho Ultima.


The Viper chassis, not very different from the chassis of the Kyosho Ultima that came later.


The Viper has a simple frame body. The Viper came as a kit, and not “almost ready to run”, like the Sidewinder.


The Viper came as a kit.


The tires of the Viper looks a lot like the tires of the Kyosho Optima, released the same year.


The AYK Viper.


4WD AYK Viper Shuttle (1985)



The Viper Shuttle is identical to the Viper, only with a lexan body instead of the frame body. I have a hard time deciding on which of the two I like best, as I think they both look stunning.


The AYK Viper Shuttle.


AYK Buffalo series


The Buffalo series consists of the Buffalo, the Bobcat and the Boxer.


2WD AYK Buffalo (1985)

Reviews (PDF): Auto8 (FR), Model Cars (US)

Manual (PDF): AYK Buffalo/Bobcat


Again AYK provided a model pre-built, and not as a kit.



The AYK Buffalo. This model is missing the wing.


In 1985 AYK released what should be their last platform of 2WD buggies. The trailing arm rear suspension was carried on from the earlier 2WD Sidewinder and the 4WD Viper series, but the gear box was brand new, and co-developed for the 2WD Buffalo and the 4WD Viper.


The old rear suspension and the new gear box.


At the front there was a newly designed double wishbone (well sort of) front suspension that marked the end of the trailing arm era of the AYK buggies, and also for the first time in an AYK buggy, sported a mono shock system and a anti-roll stabilizer. The chassis was now back to the old rail system, this time in combination with a aluminum under guard.


The new front suspension with double wishbones and a stabilizer.


In the US the Buffalo was sold through the newly formed AYK Racing USA (Condor Trading International), and the first connection with Race Prep also saw the day of light.


2WD AYK Bobcat (1985)

Reviews (PDF): Radio Control Model Cars (UK)

Manual (PDF): AYK Buffalo/Bobcat


Like the Buffalo, the Bobcat came pre built.


The Bobcat was identical to the Buffalo, only with a body reminiscent of the old Baja Bison from 1981.


A mildly modified AYK Bobcat.



Exploded view of the AYK Bobcat.



The Buffalo and the Bobcat from a Japanese magazine.


2WD AYK Boxer (1986)

Reviews (PDF): Auto RCM (FR), Radio Control Car Action (US)

Manual (PDF): AYK Boxer


The AYK Boxer. Here from an early batch, with gear diff.


Released a year after the Buffalo and the Bobcat, the 1986 Boxer marked the end of the AYK 2WD buggy era. Mostly the same car as it’s two brothers, the Boxers only new feature was larger, more modern wheels. The very latest batches of Boxers also came with a ball differential instead of the gear differentials of the earlier batches, and of the Buffalos and Bobcats. That ball diff is very rare today, due to the limited number of cars that were delivered with it.


All Buffalos, Bobcats, and most of the Boxers were delivered with gear diffs. Only the very latest batch of Boxers came with the new ball diff.


As the Boxer marked the end of the AYK 2WD era, it also marked the beginning of the AYK/Race Prep era, and the buggies that followed would rely much more on plastics instead of metal. You could say it was the end of “Metal” in the Aoyagi Metals Co. But more on that at a later time, maybe.


From a Japanese magazine.


Please Take Notice

This is not a webshop, and beside what’s listed under the “FOR SALE” tab in the menu, nothing presented here is for sale, so please don’t ask. If I have anything I would like to sell, I’ll post it in the “FOR SALE” section.

About TomEG 72 Articles
I have been into RC cars since the beginning of the 80's, but have really never been much of a racer. I competed in some local races and some "Tamiya Cups", and actually came 6th in the Tamiya Cup Norwegian Nationals in 1987. My main interest has always been building and modifying, and that's where I still am today. Through the years I have been able to build a solid network of contacts around the world, consisting of both former and current members of the industry, as well as quite a few of the former top drivers. I have a genuine interest for the history of the 1/10 scale off-road buggies from the 80's.


  1. Amazing work Tom Erik and i am impressed by your knowledge and good judgement of interesting subjects. Ayk is my favorite brand besides Kyosho. We raced sidewinders and boxers in the
    early days and radiant later on. The boxer were pretty fast and fun. Thank you for taking your time and write this, it is a brilliant article and brought back som fun memories 🙂

  2. Seeing the Viper for the first time as a child is the reason I got into RC. How cool is that car ? Off. the. chart. I never had a Viper, I would love to see one for real.

    • Hi Tommy! Try posting it on some of the vintage RC facebook pages, like “Nordic Vintage RC” etc. with good pictures (also from the underside) and a fair price, and I’m sure someone will snap it up.

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