Aluminum gains market share
One of the biggest trends in the truck wheel market is the increasing popularity of aluminum wheels, particularly among heavy-duty vehicles. According to Accuride, demand for aluminum wheels actually outstripped supply during the recent expansion market. Earlier this year, in fact, Accuride invested $22.4 million for the expansion of its aluminum-wheel production capacity and product line.
Research by Accuride indicates that among Class 5-8 vehicles, aluminum wheels represent about 24% of the market (33% of the truck market and 11% of the trailer market, on average.) Penetration is dramatically higher if you look at Class 8 alone.
In addition to their weight-savings advantage, aluminum wheels, which are made by both Accuride and Alcoa, are often preferred because of their clean, sophisticated look and relatively low maintenance. Another plus is trade-in value, since operators are said to get most of their money back with aluminum wheels.
In terms of specific products, perhaps the biggest news in aluminum wheels is the development of a wide-base product for over-the-road applications. Accuride has designed a 14-in. wheel for the X1, a wide-base tire from Michelin exclusive tovehicles. The unit, which is geared to tractor drive axles and trailer axles, is expected to result in considerable fuel savings, without an upcharge of any consequence, according to Accuride.
Improvements in the tire, specifically the recappability, have enabled the wide-base configuration to move forward into OTR applications. For fleets concerned about flat tires when using wide-base configurations, manufacturers point out that if vehicles are properly maintained, the risk is minimal.
Citing a breakthrough in forged aluminum wheel technology, Alcoa introduced its Next Generation hub-piloted wheel last spring. Addressing the issue of payload capacity, this model provides even greater weight-savings than the company's New Generation version. According to Alcoa, Next Generation wheels can boost payload capacity by as much as 630 lb. over steel hub-piloted wheels, and as much as 724 lb. over steel ball-seat wheels on a typical 18-wheel vehicle.
Load rating for the Next Generation wheel is 7,300 lb. Wheel sizes for this 10-handhole model are 22.5 x 8.25 (47 lb.) and 24.5 x 8.25 (55 lb.).
Also new from Alcoa is a forged aluminum wheel designed for the towing or hauling demands of450/550 work trucks. The 19.5-in. dualie wheel, made with eight handholes, has a maximum load rating of 3,650 lb.
In spite of all the attention paid to aluminum models as the "uptown" segment of the truck-wheel set, steel wheels continue to garner a majority of the market. Because steel wheels are cast, rather than machined, or forged, historically there has been more variability in their quality than in that of aluminum wheels. Manufacturers have been working to address this issue.
Through improvements in manufacturing technology and equipment, Accuride says that average radial run-out for its steel wheels now approaches 0.020 in. Recently, Accuride obtained a patent for a manufacturing process for full-faced light steel wheels that enhances uniformity and allows "greater contouring flexibility," giving customers more styling alternatives.
Steel wheels are subject to corrosion over time, particularly in harsh weather conditions, which affects appearance and performance. To mitigate this effect, both Hayes Lemmerz and Accuride apply E-coats to their products. In addition, Accuride has developed an optional powder-paint topcoat that is applied over the E-coating; it is said to increase wheel durability between three and fourfold. According to Accuride, steel wheels with the E-coat and powder topcoat should last between four and nine years, depending on the severity of the weather conditions they are subjected to.
Hub-piloted wheels account for the vast majority of wheels sold in the commercial truck market today. Hayes Lemmerz cites a number of advantages to this mounting system over stud-mounted wheels, including fewer wheel replacements and thus reduced operating costs, as well as lower parts inventory and easier maintenance.