Hierarchy
If you thought that a biker gang was just a group of wild men riding around and doing whatever they please, think again because they have a chain of command that they need to follow. Each member knows their rank in the hierarchy and respects the one above them or else.
We do not know exactly what the penalties are for disobeying a command from a higher rank biker, but we can assume it is not an easy punishment to take. Gangs are usually well organized and have a member in charge of various things, so they are far from just being a group of reckless spirits.