My advice:

First - get a "U" lock and lock the bike at its highest point on the frame to something solid.
Run a cable through the wheels and onto the lock.
Unless someone has a portable grinder or a set of bolt cutters, you are safe.

If some thief comes by and he DOES have a portable grinder or a set of bolt cutters, make sure that your bike is parked close to several bikes that cost at least 3 times as much as yours did, so the thief will be inclined to steal one of the other bikes instead of yours.

Don't leave your bike out over night - especially if it screams "STEAL ME" to every passer-by.

I remember someone advertising an anti-theft package designed for Harley-Davidson motorcycles...... it was a bike cover with "SUZUKI" print on it.

Binky