Imagine a Pebble...and a Harley

You are a small pebble

Lodged 

In a groove

Of a rear tire 

Of a Harley-Davidson

You are cozy there

But tightly embedded

Resting

On a concrete garage floor

Suddenly

You are disturbed

By the brief whine 

Of a starter

Then a loud

"potato, potato" rumble

Of the exhaust

It's just inches from you

And it sounds like

An avalanche 

Of your much bigger

Brothers and Sisters:  

Boulders

Spinning

Soon, you begin moving in a slow circle

That moves you like a chair in a ferris wheel

Up, then down and around

Punctuated by a regular darkness

That marks the spot where tire meets floor, then road

Right where you are lodged in the tread

You find yourself being backed into the street

Out of the quiet sanctuary of a garage

Then you hear the exhaust rise and fall

As someone prepares to release the clutch 

And launch the Harley into forward motion

Then, it happens!

The exhaust explodes in noise

You feel the force of several G's

As the motorcycle rapidly gains speed

And your Ferris Wheel spins faster, and faster

Faster

From your vantage point at the rear wheel

It seems like the world will end

At least for you

At any moment

The wheel is spinning so rapidly

The tire is warming and expanding

Which makes your perch in the tread

Loosen and seem all the more precarious

At any moment you may be thrown free

And land who knows where?

This is not a proper existence 

For a small pebble!

But then you realize

It could be worse.

You could be a 

Boulder

That is wearing away to a rock

That is wearing away to a stone

That is wearing away to a pebble

That is wearing away to a grain of sand