If you thought changing a Car Tire was hard . . .
The spoked part is equivalent to a car's 'rim' (don't know what it's called), the outer part is actually called the "tire", and tires wear out and have to be changed. (That's what's being done here.) The two parts make up the "drivers". I guess AAA doesn't do steam engine tires. ;^)
|AF4_2483 Surfing the Serengeti by DaveInHouston|
from Hot Air Balloon view
|Peregrine Falcon by Psychic1|
from Best Wildlife Photo of the Week - 4