As Vonderbach stated, the best instal is on the upper engine mount.
If you are looking for the best outcome from a serious crash keep the frame slider short with only about a half inch protruding past the fairing. Any more than that and you are likely to create more damage than they are worth.
I learned the hard way that long frame sliders tend to dig into the dirt when the bike leaves the pavement and causes the bike to flip and continue to tumble causing extensive damage. The trick is to keep the bike on it's side throughout the crash. Fairings are cheap if you can keep it on one side. When she tumbles does damage all the way around, tank, gauges, fairing stay, clipons and the list goes on and on.
Vortex sells a stubby slider that protrudes just past the fairing. I use these on the race bikes as well as street bikes. I have repaired my fair share of crashed bikes and I can say with athority, these are the best for serious crashes. The longer sliders are great for slow parking lot or driveway spills but not so good for speed.
