Frame Question.
 

How hard does your bike have to take a hit for the frame to break like on alpha aluminum?

The question is too general. You cant measure a frame by how hard of a "hit" it can take.

ok im goin off a 15 ft drop..would there be to much force passing the rear shock to bust the frame?

All comes down to frame design and the way the shocks are set up. Also depends on how smooth you ride and land. If you land wrong or have the bike set up wrong then there is a very good chance the frame will crumble.

Frames are generally quite strong. It would have to be a huge force to physically break a frame. More likely is frame failiure from repeated, but lighter forces.

Try it and let us know!