Tire shake is a nasty thing, but it just comes with the territory when you’re making horsepower, and tons of it. Not only can it damage chassis and other components on the car, but it can leave the driver with quite a headache and even a few loose fillings. No joke.
For the uninitiated, tire shake is simply a point at which there’s not enough tire speed, nor not enough tire speed. The tires are both trying to grab the race track and attempting to spin all at once, and the result is a balled-up tired that’s out of round and typically square-off at the contact patch. That is, if there’s any contact still being made, as tire shake victims often will have blue sky underneath both rear tires in case of truly violent tire shake.
Top Alcohol Cars tend to be exceptionally prone to cases of shake, and this video filmed at the Grand Bend Motorplex aboard an unidentified alky-burning Funny Car illustrates just how violent it can be. As you can see, the GoPro camera is mounted on the single lower wheelie bar, just forward of the wheel, looking forward toward the rear end housing and the tires. The car launches cleanly but right before the 1-2 gear change, goes into some brutal shake, which unfortunately knocks the camera mount loose and limits our view of what’s going on. If you look closely, however, you can see the outboard sidewalls of the slicks oscillating with extreme force until the driver wisely lifts.
From the viscous gyrations of the camera, you can get a pretty good feel for what the driver goes through in these situations, and it leaves you to wonder how they’re able to walk straight or even remember their own name after being shaken like a can of paint in a malfunctioned mixer.
And how do you cure tire shake? Well that’s the million dollar question, and the reason why good crew chiefs are called good crew chiefs: with enough wheel speed to keep the tires round, but not so much that the car goes up in smoke. It’s truly a delicate balance. Perhaps even an art.