One of my pet peeves is the modern usage of the term "rim" to describe aftermarket alloy wheels. Perhaps this is one of those long standing debates that will never be resolved but it's important to use the correct terminology when discussing parts.
The rim is the outer barrel portion of the wheel where the tire is mounted.
The term wheel applies to the entire assembly so anyone who says they are going to purchase some rims for their car is not using the correct terminology.
If they intend to purchase an entire assembly, they should say they are purchasing wheels, not rims.
It's a small point but it still bugs me when I hear it used incorrectly.
Perhaps looking at the origin of the word rim would help clear things up.
I believe a lot of the confusion goes back to the very early days of automotive history when it was common for cars to use something called detachable rims. These early vehicles had wooden wheel centers much like what you would have seen on a horse drawn wagon.
Mounted to the outside of the wooden center was a removable assembly made up of the steel rim, a rubber tire and a rubber inner tube.
This design was intended to make it easy to dismount the rim and tire as a complete unit. The rim itself was secured to the wooden wheel center using retainer bolts threaded into the wood. as seen in this close-up.
When you got a flat tire, it was a 'simple' matter of pulling over and switching out the rim and tire assembly. Here's a nice series of vintage photos showing the process:
Here's the damaged flat tire on the steel rim. You can make out the dark rim retainers along the edge of the wooden wheel rim. These would be un-bolted with a wrench.
Here's a nice close-up of the rim retainers. The nut 'floated' in the seat of the retainer so they could spin freely. When tightened, they clamped the edge of the steel rim down against the wooden wheel center:
Once they were removed, the entire rim and tire assembly could be lifted off of the wooden center.
Then it was time to slip the new tire and rim assembly back on the wooden center. It was so easy you could wear your Sunday best coat and gloves!
Many multi-piece alloy wheels are still constructed from separate rim sections and center discs like this O.Z. Racing three-piece wheel:
The centers drop into the rim sections and are bolted in place from the front of the wheel.
So in reality, you purchase wheels, not rims!
I want to send out a special thanks to Mr. John M. Daly for allowing me to use some detailed photos from his website, the E-M-F 30 Homepage.
For more info about detachable wheels and to learn about the history of the E-M-F 30, check out his organization's website:
It's a wealth of information about this fascinating vehicle and its history.