If you wanted to force motorcycles to crash utilizing a sniper rifle from no more than 800 yards, what part of the bikes would you aim for to not only cause the rider to lose control, but not leave evidence of the crime? The causing event would have to result in plausible crash-related damage.
(EDITED INFO: This is for a screenplay; main character is a retired USMC Desert Storm-era sniper; soundproofing room used; weapon is based on IRL rifle manufactured with suppression; targets are in bustling city during daytime).
Obviously the issue about bullets made of ice, dry ice, mercury, etc., has been debated, so the target is the machine rather than the rider. Would a piece of gravel (or similar, common item) have the velocity and ability to complete this task, or would a bullet that shatters on impact be the better choice?