|This article is about a/an set of attachments in Kamen Rider V3.|
What Riderman lacked in technological strength of V3, as well as the Riders before him (Riders 1 and 2), he made up for in persistence, smarts, and his wide array of prosthetic weapons that he had named the Cassette Arms (カセットアーム Kasetto Āmu) to meet his needs. His weapons were also the basis for the "Rider Slash" and "Rider Shooting" finishing attacks.
The equipment of a bionic arm was a necessity for Joji Yuki, whose right arm was destroyed after being dipped into a pool of acid during an execution attempt, having been framed by Marshal Armor. However, Yuki was rescued by his fellow Destron Scientists who performed the operation which not only replaced his arm but allowed him to transform into Riderman to get his revenge.
- Rope Arm (ロープアーム Rōpu Āmu): Riderman's default/primary Cassette Arm, which is used in various ways: as a means of escape, climbing, and in combat. The arm itself has modified attachments for Yuki to use and adjust to various situations.
- Hook Arm (フック－アーム Hukku Āmu): A hook attachment for climbing and combat.
- Swing Arm (スウィングアーム Suwingu Āmu): A mace attachment, which can be extended and used as a flailing weapon.
- Net Arm (ネットアーム Netto Āmu): An attachment where Yuki's arm can shoot out a net to capture and restrain enemies (by Kamen Rider Spirits, it appears that this net is fireproof).
- Sickle Arm: An unused kusarigama attachment, which has been seen in various promotional material; and yet, wasn't used in the series. Based on the photos, it is assumed it is simply used for combat.
- Power Arm (パワーアーム Pawā Āmu): Riderman's strongest weapon, which increases Yuki's attack in battle. Its primary use is to hack away at both obstacles, such as doors, and opponents. This weapon could've been easily used as a finishing attack, according to some fans. This weapon is the first instance of a Rider using a blade against a monster, which would later be a frequent armament in the Heisei Era-Riders.
- Drill Arm (ドリルアーム Doriru Āmu): Another weapon could've been easily used as a finishing move. It was only seen being used as an infiltration tool. It must be plugged in order for it to work best, although it will still work otherwise (by Kamen Rider Spirits, it appears to work just fine without external power).
- Machine Gun Arm (マシンガンアーム Mashin Gan Āmu): A concept drawing seen in Ishinomori's artwork, this Cassette Arm would not be used in Kamen Rider V3 and resembles a Gatling gun. A revised version of this weapon was seen in the Kamen Rider Spirits manga. It was used to destroy the revived Marshal Yoroi in the manga and had the appearance of an assault rifle machine gun.
However, this weapon eventually made a live action appearance in the Kamen Rider Taisen film. Riderman uses it to block Kamen Rider Fourze's Gatling Astro Swtich module's gunfire. Later, it was used again in Super Hero Taisen GP: Kamen Rider 3.
Its appearance here resembles his other Cassette Arms with a machine gun muzzle attached to it. This weapon is the first instance of a Rider using a gun against a monster, which would later be a frequent armament in the Heisei Era-Riders.
- Octopus Arm (オクトパスアーム Okutopasu Āmu): Currently, it is only an unused concept and an SIC exclusive accessory. Its function is described as a climbing tool, each finger on the hand resembling octopus tentacles.
- Chain Arm (チェーンアーム Chēn Āmu): Currently, it is only an unused concept and an SIC exclusive accessory. A harpoon-like attachment connected onto a chain.
- Operation Arm (オペレーションアーム Operēshon Āmu): It is appears only as an SIC weapon accessory and in manga. It is designed to fix and repair electronics and machinery. In Kamen Rider Spirits, Joji Yuki used it to repair V3's Double Typhoon.
- Control Arm (コントロールアーム Kontorōru Āmu): It is not used in the TV series. In Kamen Rider Spirits, it was used to control the Space Break System of Badan.
- Smoke Arm (スモークアーム Sumoke Āmu):It is not used in the TV series. It can fire tear gas or create a smoke screen.
- Fire Arm (ファイヤーアーム Faiyā Āmu): Currently, it is only an unused concept. It is a flamethrower.
- Freezer-shot Arm (フリーザー・ショット・アーム Furīzā Shotto Āmu):Currently, it is only an unused concept. It can fire liquid nitrogen.
- Crab Arm: Currently, it is only an unused concept. It is a crab arm.
The A.R. version of Joji Yuki from the World of Decade, while not shown transforming into Riderman, had a prosthetic arm similar to the original. He had lost his right arm in similar circumstances under the orders of the Great Leader of Dai-Shocker having previously served Dai-Shocker as a scientist.
- Blaster Arm (ブラスターアーム Burastā Āmu): This weapon is used while he is in human form. It is activated when Joji rips off his prosthetic arm and attaches the weapon part onto himself. This is seen in Kamen Rider Decade: All Riders vs. Dai-Shocker and in "The Next Decade" MV.
- Blade Arm (ブレードアーム Burēdo Āmu): Only shown in concept art.
- Power Arm (パワーアーム Pawā Āmu): Only shown in concept art.
- Cassette Arm: Only shown in concept art.
In Kamen Rider OOO: OOZ, Ankh possesses Joji Yuki, causing his normal Rope Arm to transform into a new form. The Red Cassette Arm (赤いカセットアーム Akai Kasetto Āmu) boasts a rope launcher, small missile launcher, chain gun, and an electromagnetic knife, giving Riderman the power to battle Shocker OOO and the Shocker Greeed.
In the OVA Kamen Rider SD: Strange!? Kumo Otoko, the SD Riderman has the Power-Arm equipped through the whole movie, although it seems to function like the Rope Arm too as demonstrated in the opening.
- The Cassette Arms introduced the concept of Kamen Riders regularly using weapons in addition to hand-to-hand combat, which would be immediately followed by X-Rider's Ridol before disappearing again until becoming prominent in Kamen Rider Black RX and throughout the Heisei era.
- In his television appearances, Riderman equipped different Cassette Arms by sliding his bionic arm into the weapon itself, which existed as an external object. In the Kamen Rider Spirits manga, he instead slides different cassette-shaped mechanisms, which are carried in a pouch on his belt, into his bionic arm from behind the elbow, which reconfigures his arm into the desired Cassette Arms weapon.