A Bicycle is an item used to travel great distances in the Pokémon World.
Misty, May and Dawn have all previously owned bicycles in the past, but they have all been destroyed by Ash's Pikachu. In Pokémon - I Choose You!, Ash stole Misty's bike to escape a flock of wild Spearow, but it was destroyed by ThunderShock. In Get The Show On the Road!, May's bike was destroyed by Pikachu's Thunderbolt while trapped in Team Rocket's new robot. Pikachu also used Thunderbolt to accidently destroy Dawn's bike when his Thunderbolt struck Dawn's Piplup.
Bicycles can be rented to use on Cycling Roads as seen in The Bridge Bike Gang and One Big Happiny Family!. Some characters do own bicycles but are rarely seen using them. For example, Professor Oak used a bicycle in The Power Of One to get to Delia Ketchum's house, but it was knocked aside by Dugtrio.