I don't know what alloy the yamahas are but I extrude the pieces for the honda (before they get welded) and they are 7003 alloy......Other likely alloys are 6061/KN63 and 6063.

I'm not sure if thats what u were looking for but I hope that helps

 

true that sir. didnt think of that. lol cover that rear break so you dont hit it hard.

 

Thanks snipes thats the kind of information I was looking for.