Rotate the tires and see whether the shake moves
A vibration can come from a tire and wheel assembly, or from the vehicle itself: a worn part, a driveline fault, a brake problem. Working out which saves a lot of guessing, and a tire rotation is a free experiment that often answers it.
Note where you feel the vibration and at what speed before the rotation. Then drive the same road at the same speed afterwards.
The shake moved. If it was in the steering wheel and is now in the seat, or the other way round, it traveled with an assembly. The problem is in a tire or wheel that changed position: imbalance, a tire out of round, or a bent wheel.
The shake stayed exactly the same. It did not travel with any tire, so it probably belongs to the vehicle: a suspension or steering part, a driveline component, or the brakes.
The shake disappeared. Sometimes the act of removing and refitting a wheel cures a vibration caused by a wheel that was not seated evenly. Worth knowing, and worth mentioning.
Tell the store what you observed. It shortens the diagnosis considerably.
When balancing is the answer
Every new fitting is balanced. Beyond that, ask for a balance when a shake follows an assembly, when a weight has visibly come off the rim, or after a tire repair. A vibration that survives a balance is often the wheel, and wheel refurbishing is here. A pull rather than a shake is alignment. The national tire and wheel balancing page covers the other occasions worth asking for it.
This is the Commercial & Consumer listing; the Phoenix city page explains the others.
Other stores nearby
Casa Grande and Tucson also balance tires and wheels.
About this store
The Phoenix store carries all nine Purcell tire categories and is managed by Patrick Taylor.
See the national tire and wheel balancing page for all 51 locations.