Back in the olden days — the 1970s when I first entered the trucking industry — most trucks, tractors and trailers had either spoke, demountable wheels (also known as Dayton wheels) or stud-piloted disc wheels (also known as Budd wheels).
Two- and three-piece rims were also in use although even at that time there was a national effort to ban these "killer wheels." Western fleets were the first to use disc wheels and gradually their use spread eastward across the country.
Almost every fleet ran steel wheels, and usually only owner-operators put out the big bucks for aluminum wheels that made their rigs sparkle and shine.
There was also a common belief that aluminum wheels were not as strong as steel and if you hit a pothole your wheel might break.
Beginning with deregulation in the 1980s, fleets basically scrapped existing equipment and bought new. They traded in their 45-foot trailers for 53-foot trailers and 28-foot pups that could be used in doubles configurations, which deregulation made legal for the first time.
Smart truck engineers also started to look at reducing weight in order to reduce vehicle weight and haul more stuff.
Those with foresight also began thinking about reducing weight to improve fuel economy. And so, fleets started to spec lighter aluminum wheels.
Since freight haulers were scrapping their fleets and buying new, this was also a good time for them to begin making the change to hub-piloted wheels (also known as Uni-Mount wheels).
Many fleet engineers first specified just the wheels on steer axles in aluminum. Others put aluminum wheels on the steers and outside duals (this made drivers happy since the truck looked sharp but was cheaper than making a commitment to the entire vehicle), and a few took the plunge and equipped all 10 wheels on their tractors with aluminum disc wheels.
Over the years, aluminum wheels proved they were strong and could take the abuse of heavy axles and formerly fatal potholes as well as offered the benefits of lighter tire weight.
As a result, aluminum took a larger share of the wheel market. By the new millennium, the commercial truck wheel market was about 50/50 aluminum to steel wheels.
Since then, the emphasis on reducing fuel consumption has continued to spur their growth. Wheel manufacturers designed aluminum wheels specifically for wide-base tires, which further decreases the weight (over 1,200 lbs.) on tractor-trailer rigs.
Today all over-the-road fleets are running disc wheels and the only demountable wheels in use can be found on vocational trucks such as those used in coal mining.
Multi-piece rims/wheels are almost a distant memory since they haven't been made in North America for decades, although every once in a while you might find a very old vehicle equipped with them.
Aluminum wheels have 62 percent of the Class 8 truck market and 18 percent of the trailer market. Stud-piloted, ball-seat, double-cap-nut wheel systems have just about faded into the sunset as hub-piloted wheel systems own about 99.9 percent of the Class 8 market.
Fleets don't normally replace wheels on their trucks, tractors or trailers. Usually wheels go out the door when the vehicles are traded. However, they must be replaced when they exhibit out-of-service conditions.
Therefore you have two opportunities to identify wheels that should be removed from service and replaced. They are when you are refinishing wheels and when you are mounting/demounting tires on wheels.