While some ROM hacks might introduce new items or features, it's not something that's a standard part of Ash Gray.
Here are some options you could consider if you want a bike-like feature in Ash Gray:
* Look for Mods: Search online for mods specifically made for Ash Gray. Some might introduce bikes or other forms of transportation.
* Use Cheat Codes: If you're playing on an emulator, there might be cheat codes available that allow you to get a bike or other items.
* Change the ROM: If you have some technical experience, you might be able to modify the ROM yourself to add bikes. However, this can be complex and risky.
Remember that using cheat codes or modifying ROMs can impact your gameplay and potentially void any warranties you have on your game or emulator.