Strange Demon Robot
The Strange Demon Robot unit is led by Captain Gatezawn, composed of various androids built by Gatezawn.

A robot Gatezawn sent after Kotaro. He disguised himself as a human after stealing some of Hayami's clothes. When exposed after his synthetic skin catches fire, Cublican grew a new head after RX knocked his original off. Kamen RX absorbed the sun's rays to recharge before calling for Acrobatter, using the Revolcane to destroy Cublican.
Episode 2
A large robot with tank treads instead of legs sent to kill RX before he completed Rideron, Gungadin attacked with his body guns. Unable to defeat Gungadin on his own, RX tricks Gungadin into thinking he destroyed Rideron while the real car gains life. Offered the title of knight if he killed RX, Gungadin went on a killing spree to force the Rider out into the open. With the aid of Rideron, RX managed to defeat the Demon Robot with his Revolcane stabbing him into the head module.
Episode 4

A robot that was destroyed by Lord Crisis for being too powerful for the Crisis Empire to control. Gatezawn salvages Scryde and revives the monster, sending him to Earth to use discarded items to seal people before having his army attack humans. Though he nearly killed RX, Kotaro escapes with few injuries as he has Rideron and Acrobattler to break Scryde's hold over his garbage army. Once he knocks Scryde's head skin off, RX destroys him with the Revolcane in order to free the humans from within the discarded items.
Episode 11
A humanoid insect robot sent after Kotaro while Hitomi was kidnapped by Maribaron. RX uses him to enter the Desert of Death after Maribaron. As a result, Deathgaron is attacked by Triplon before he offers his services to Maribaron in return for redemption. However, Deathgaron is deceived and ends up being sealed up with RX as he kills off a replica of Hitomi placed there. This in turn causes RX to transform into RoboRider, breaking out of the sealed room and using his Voltic Shooter to heavily damage Deathgaron. Before he died from his injuries, Deathgaron revealed that Hitomi is still alive and with Maribaron.
Episodes 14-15, Movie

A robot that first appeared in its splintered form: Triplon Unit 1and the humanoid Triplon Unit 2 and Triplon Unit 3. Triplon is deployed to the Desert of Death to execute Deathgaron for his incompetence before serving as an escort to Maribaron. When Nexticker is destroyed, the Triplon Units capture Shigeru and overwhelm Kotaro and Joe before they are captured. But when RX achieves the form of BioRider, the Triplon Units dock into United Triplonwhich BioRider destroys with his Bio Blade.
Episodes 15-17, Movie
A blue robot sent to attack Kotaro while he was looking for Hitomi. Controlling Joe as a puppet, Nexticker forces him to fight Kotaro when he almost saved Hitomi. After surviving the attack, Kotaro is ambushed by Joe while on his to the Valley, fighting him as RX before disabling the robot's mind control abilities. Assuming the form of RoboRider, RX converts Acrobatter to Roboizer and overwhelms Nexticker before blasting him with the Voltic Shooter.
Episode 16
A robot that can manipulate heat.
Episode 19
A fire-elemental robot. He can manipulate fire. When the Crisis Empire was still hording water, people continued to get them from Maribaron's performing troops. After a brief battle with Maribaron, Gatenzawn, and Gedorian, Kamen Rider Black RX located where the water was being withheld and fought Metaheavy who pulled Kamen Rider Black RX into its fiery location in the factory, where it had the advantage. RX became Robo Rider and managed to knock Metaheavy out of the room. After a few shots on Metaheavy with his Vortech Shooter, Robo Rider reverted to RX and destroyed Metaheavy with the Revolcane, then used the Revolcane to destroy the controls that were withholding the water, thus returning the water to the city. Metaheavy was later revived by Maribaron as part of the Spirit World Kaijin Army.
Episodes 30 & 45
An electrical robot. Elgitron was later revived by Maribaron as part of the Spirit World Kaijin Army.
Episodes 31 & 45
An Asura-like robot. He wields a spear, two swords, a sickle and a pitchfork in battle. He can also spew acidic foam from his hands. Disguised as a headmaster, he helped General Dasmander (disguised as a female worker) and Gatenzone manipulate children with ESP into causing the country to split from the continent. Kotaro encountered Schraigin first, and henshined into Kamen Rider Black RX to fight him. When Kotaro found where the other ESP children were, he was discovered by Dasmander, Gatenzawn, and Schraigin. Schraigin fought Kotaro before shedding his disguise. Kotaro then transformed into Robo Rider and fought the Chaps and Schraigin. After the machine that the ESP children were attached to was destroyed, Dasmander and Gatenzawn fled as Robo Rider engaged Schraigin outside. Robo Rider reverted to Kamen Rider Black RX and used the RX Kick on him. He then called out his Revolcane and disarmed Schraigin before using the Revolcane to destroy him.
Episode 34
A robotic monster resembling an automobile. He was used to capture children and use the Strange Demon gun computer to transform them into killer machines to be used to kill Black RX. He was destroyed by RX's Revolcane.
Episode 39
A silver humanoid robot. He can shoot his fists out like missiles. He was commanded by Gatenzawn and battled alongside him.
Episode 43