Wheel | Wenatchee, WA |December 2019

Circle Series #2 | I understand how tires work. Tread reduces skids; air reduces bumps. Tires are third on my list of Car Parts I Understand, right after horn and glove compartment. But my list of mystery parts (transmissions, brake calipers, adjustable lumbar cushions) grows longer as cars evolve. For instance, the engineering of our windshield wipers — one short, one longer with a dogleg — yields maximum squeegee action on a convex surface. Blows my mind. And let’s not even talk about CV (constant velocity) axles and how they make a car go. What I know is that the axles drive the wheels which are encircled by tires. And I understand tires.

[In photo: Front left wheel on a beautifully restored vintage Ford pickup truck.]