The Bicycle is an item in EarthBound. It allows Ness to move faster, and is donated by the cashier staffing the store Punk-Sure. However, only one person can ride it, making it unusable when there are more people than simply Ness in the party, including the teddy bear. After rescuing Paula, the bike can be returned to the shop, since the addition of one more character in the party renders the bicycle completely useless.
The Bicycle later makes a cameo appearance in Mother 3. It is on display in the Empire Porky Building's Hall of Memories. However, it cannot be ridden, and is only seen by Lucas and co. as their boat drifts by its pedestal.
In the Mother 1+2 Art Book, several pieces of concept art of Jeff with a yellow Bicycle are shown, implying that Jeff was originally planned to be able to ride a Bicycle and have a backpack similar to Ness.