In the Grand Theft Auto Online update 'Bikers', the ability to melee other players, enemies, and NPCs (Non-Player Characters) was introduced. There are other tutorials on how to use melee from a motorbike in-game however they tend to omit some key information that will be included in this guide.
Anything aside from throwables that you normally have access to on a bike can be used in melee (yes, even pistols), not just melee weapons as most have stated. Others have also stated that you must be moving slowly on the bike in order to perform the actions. While this will potentially improve the accuracy of your attack, it is not necessary and can be done at any speed.
On to the guide:
On PlayStation 4
- You must be on a motorbike.
- Have some sort of a non-throwable item out (or nothing aka hands)
- Hold X
- Press L1 and R1 to attack on each side respectively. (if no weapon is selected, your player will kick with their leg)
On Xbox One:
- You must be on a motorbike.
- Have some sort of a non-throwable item out (or nothing aka hands)
- Hold A
- Press LB and RB to attack on each side respectively. (if no weapon is selected, your player will kick with their leg)
On PC:
- You must be on a motorbike.
- Have some sort of a non-throwable item out (or nothing aka hands)
- Hold X (on keyboard)
- Press Left and Right mouse button to attack on each side respectively. (if no weapon is selected, your player will kick with their leg)
The result:
[Video Source: Nuckha]
Disclaimer:
As announced by Rockstar Games, the creators of the Grand Theft Auto franchise, any updates released after heists unfortunately are not on previous generation consoles (PlayStation 3 and Xbox 360) due to technical limitations of the older hardware.