I don’t understand. 3 of them are bikes but how do I know what they do? Whatever bikes they are in real life, it is the same and the Pokémon world is alike!
The Mach Bike allows players to move a lot faster than regular Bicycles and the Acro Bike (16 steps per second in Generation VI). It can move fast enough to ride straight up muddy slopes, or over cracked tiles without falling through (which appear in Granite Cave, the Sky Pillar, and Mirage Tower(E)) if the player has enough speed. If the player collides with something, then the speed resets. On the Seaside Cycling Road, a player's time and number of collisions while riding this Bicycle from the northern entrance to the southern exit are timed and recorded. This is part of the data sent over to other players via record mixing.
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The Acro Bike travels at the same speed as regular bicycles (10.67 steps per second in Generation VI), but it also allows players to perform tricks, such as wheelies and bunny hops, which let players reach special areas. It can also be used for traveling on white rails found on Route 119 and in the Hoenn Safari Zone. Bunny hopping up and down on an Acro Bike in tall grass can cause wild Pokémon to appear, but does not count as steps towards the Safari Game or Repel.
source Regular bikes are unobtainable in Hoenn games.
