Explaining the joy of riding a motorcycle is difficult, but Dave Karlotski does it as well as anyone in his essay Season of the Bike.
A ride on a summer afternoon can border on the rapturous. The sheer volume and variety of stimuli is like a bath for my nervous system, an electrical massage for my brain, a systems check for my soul. It tears smiles out of me: a minute ago I was dour, depressed, apathetic, numb, but now, on two wheels, big, ragged, windy smiles flap against the side of my face, billowing out of me like air from a decompressing plane. Transportation is only a secondary function. A motorcycle is a joy machine. It's a machine of wonders, a metal bird, a motorized prosthetic. It's light and dark and shiny and dirty and warm and cold lapping over each other; it's a conduit of grace, it's a catalyst for bonding the gritty and the holy.