@Amiaeful86
We have had many calm talks about expectations and he nods and agrees in the right places but then does nothing. I will not be paying towards his bike again under any circumstances or giving him money.
I have also done a job list where he can earn money etc and help out but that lasted a week and he binned it
What have you done to address your own behaviour and to take responsibility for the part you have played in creating and sustaining this dynamic? Blaming him for everything is easy, but inaccurate.
You keep saying one thing with your calm lectures then go off and do the complete opposite. Telling him to buck up and value money but then chucking thousands of pounds at him like it's nothing. What is the lesson there?
Your words may say one thing but your actions shout the opposite.
Does he have the same dad as his brothers? Or has he grown up with an absent father but siblings who have a present father?
Either way, he wouldn't be the first child to feel so rejected by an absent father that they try to push everyone else away so that they will "hurry up and admit they don't want me either".
You acknowledge yourself you overcompensated and didn't know how to support him with his dad's absence. The answer to that isn't to wash your hands of him now that those mistakes have come home to roost.
I think it would be unethical to put all the blame on him for the way he's been let down - whether deliberately by his father or inadvertently by you - by the adults in his life. It certainly wouldn't be effective to motivate him.
It's uncomfortable to face up to your role and responsibility in this, so I expect you'll be defensive. Denial and defensiveness won't get you anywhere though. I'm not judging you, I can see you tried your best and had positive intentions, but now is the time to reflect, acknowledge the mistakes and change.
Your son sounds angry at the world and like he hates himself so much he's trying to self-destruct. I can see how he could have come to feel that way. He doesn't need you to reject him too.