Transformers: Generation One 
The Duocons sub-group is particularly small, consisting of only two members, Battletrap and Flywheels. First released in 1987, they are distinguished by their unusual transformation ability to split their single robot form into two separate vehicles. By placing the flying vehicle atop the wheeled one and pressing down until they click into place, the toy quickly springs up into robot mode.
His fellow Decepticons describe Battletrap as "playful" - in the same sense that a cat is playful with a captured mouse before moving in for the kill. His two components are a robotic wrestling tag-team, and he loves to trap an adversary between his two modes and have his own special kind of "fun" with him before finally ripping him to pieces. Surprisingly, Battletrap is cheerful and good-natured - but that's probably because he enjoys his work so much.
Battletrap can divide his robot into two separate and autonomous vehicle modes, jeep and helicopter, each with identical personalities, and can recombine into robot mode in 1.6 seconds. His helicopter component is equipped with a vast array of electronic detection, jamming and communication equipment. Although strong in robot mode, his alternate modes sacrifice this for enhanced mobility - neither is especially rugged or weapons-fire-resistant. In all three modes, Battletrap uses a double-barreled, wire-guided assault missile launcher with infra-red imaging for night-firing capabilities. Curiously, the jeep is very similar to an ARO 10.
Whereas the division of Battletrap's personality between his components seems to have been a successful one, Flywheels (Flywheel in Japan) is far from it - his two vehicular components possess individual personalities, and they loathe each other. Each half of him is jealous of the other, leading the two minds to fight with themselves more often than with his opponents. Flywheels can even be heard arguing with himself when his components are unified in robot mode. He divides into a tank and a jet, and all three modes can wield his laser cannon, equipped with infra-red sensors for heat-seeking capabilities.
Animated series 
The Duocons did not appear in the American animated series proper, but Flywheels can lay claim to a small cameo in the opening sequence to the fourth and final season. Although it is odd, since the Duocons do not appear in the series, a clip of the unique animation created for the Duocon toy commercial was employed in the opening credits, giving Flywheels a second or two of screentime.
Transformers: Headmasters 
In contrast to America, the Duocons made a full foray into animation in the 1987 Japanese-exclusive Transformers: Headmasters animated series. No origin for them was explicitly offered - they suddenly appeared towards the end of the series when Scorponok and the Decepticons returned to Planet Master; presumably, they had remained on the planet when Scorponok and his troops departed prior to the start of the series. The Duocons were first mobilised into battle to steal a disk containing the blueprints of Fortress Maximus's Master Sword, which Battletrap successfully purloined. The duo subsequently defended the Decepticon base while the blueprints were used to create the Zarak shield, and planted a bomb on an asteroid as part of Scorponok's plan to betray and abandon Sixshot. Back on Earth, they participated in a huge final battle at the North Pole, during which Battletrap attacked Daniel Witwicky and Wheelie, only to be stopped by a vengeful Sixshot.
Marvel Comics 
The story of the Duocons in Marvel Comics begins in the United Kingdom's exclusive Transformers comic book series, where they both appeared to battle the Autobots Ultra Magnus and the Sparkabots, who had only just returned to Cybertron. Flywheels was rendered unconscious during the fight and captured by the Autobots, who took him into the deserted city of Kalis. Awakening, Flywheels was terrified to discover where he was, and the Autobots soon shared his fear as reanimated Transformer corpses soon emerged from the ground around them, revived by the renegade Autobot mad scientist, Flame, to guard his operations beneath the city. Battling the zombies alongside the Autobots, Flywheels was released by Magnus and proved loyal enough to fetch help, returning with the giant Trypticon to offer aid.
A little later, both Flywheels and Battletrap were members of the Decepticon Mayhem Attack Squad that arrived on Earth to battle the time-travelling Galvatron as a rift in time and space threatened the existence of reality. Battletrap was apparently killed by Galvatron during the conflict, and while Flywheels did not receive an on-panel death, he did not appear again.
The reports of Battletrap's death soon proved to be exaggerated, as he later appeared in the U.S. Transformers comic book series. Attacked by subterranean Cybertronian monsters shortly after the defeat of Unicron, both Battletrap and Runabout were apparently consumed by the beasts, but Battletrap once again proved his resilience (admittedly, only Runabout had been seen to be killed), appearing again during the Decepticons' attack on the planet Klo and in battle against Jhiaxus's second-generation Cybertronians, where he was seen to have been wounded (though is not seen to die).
In the UK comic series, Flywheels was depicted as a triple changer able to transform into either a Tank or a Jet, but not both at the same time. Battletrap was shown only to transform into Helicopter mode.
In the US series, Battletrap was only shown in robot mode.
While Battletrap didn't receive much characterisation, Flywheel in the Kalis story was written along the lines of Battletrap's tech spec rather than his own.
Dreamwave Productions 
Although the Duocons themselves would only have minor roles in Dreamwave Productions' 21st Century re-imagining of the G1 universe, with Flywheels appearing as one of Starscream's Predacons, they did receive profiles that established them as part of an important legacy. Prior to the planetwide deactivation of Cybertron, Shockwave had been experimenting with the possibility of creating Transformers with multiple alternate modes. Following Cybertron's reactivation, he resumed his experiments, and the Duocons were his first creations - robots who possessed the power to split their forms into two independent vehicles. Their comparative instability, however, led Shockwave to continue his work, eventually resulting in the creation of the more stable Triple Changers - robots with the ability to transform into one of two modes alternately.
Fun Publications 
Battletrap, Crankcase, Gutcruncher and Stormcloud appear among Bludgeon's troops in the story At War's End by Fun Publications. They help remove Abominus after the Terrorcon combiner had been defeated by Piranacon when it is believed that Hun-Gurrr sold out Bludgeon to Megatron.
- 'Generation 1 Battletrap
- A new mold.
- 'Generation 1 Flywheels
- A new mold.
- Alvarez, J.E. (2001). The Unofficial Guide to Japanese and International Transformers. Schiffer Publishing Ltd. p. 27. ISBN 0-7643-1282-0.