Bicycle appears in 8 version groups since Generation I, a Gameplay item in the Key Items pocket
PokéAPI item 427 of 2,223, Gameplay category, Key Items pocket
Effect, in PokéAPI's words
Bicycle: “Use for fast transit.”
Increases movement speed outside or in caves. In high gear, allows the trainer to hop over some rocks and ascend muddy slopes.
Games
Bicycle is listed in the text of 8 version groups, first in Generation I
Game index by generation
IIIIIIIVVVIVIIVIIIIX
Named in
EmeraldFireRed and LeafGreenDiamond and PearlPlatinumHeartGold and SoulSilverBlack and WhiteBlack 2 and White 2X and Y