my car shakes

[brewcrew]

hello guys i was wondering what could be the problem, i changed my rotors on the front but when i drive at high speeds around 70 or 80 and hit the breaks to slow down it starts to shake iam not sure what is the problem can any one help me

[96_323]

If you didn't wear in your disks properly when you got them then they may have warped, it's not to expensive to get them machined.