How to change bike in Days Gone

You can use a different bike, but for this you need to fulfill a number of conditions.

The best option is when you stumble upon an enemy while exploring the game world, which also uses the bike. Wait, while he stops and parks his bike, then sneak up and steal this transport.

There is one limitation for this case. The game will not allow you to swap your current bike for another, if it was damaged, eg, An NPC crashed into an obstacle while chasing you, or you shot at his bike

Consider, what if you want to run away from bikers, much more profitable not to steal any of their bikes, but just damage them all, thereby sabotaging the ability to go somewhere. Yes, the limitation above also applies to NPCs, if their motorcycles were parked and there was no one on them at the time of the damage.

As for the bikes, which are in parking lots, then in Days Gone the protagonist cannot use them, like the bikes, appearing in all other cases.