fosing
Super Freak
They have the advantage of being able to immediately disable tires, whereas it's conceivable that the rider could control the bike through the oil. Their big disadvantage is that unless you have hundreds of them, they don't cover the road as thoroughly as oil.
Flammable oil slick would be best. Or exploding caltrops. Or miniature magnetic mines. Or an SUV used as a battering ram (the only drawback being that the driver could have an unhealthy respect for life, to the point that he couldn't bear to kill people who threatened his family).
Myself, I'd go with the last option. My respect for life stops at the safety of my loved ones.
protective instincts come out naturally.