Automotive market inspires improved construction tire design
Nothing is certain in this world except death and taxes … or so says Benjamin Franklin. Another certainty should be added to that list—equipment isn’t getting any smaller. Each year, manufacturers tout higher horsepower, greater payloads, extended lifts, and larger bucket capacities. As machines evolve, standard tire designs are expected to keep up.
Many believe we’ve reached a tipping point, and standard tires are now inhibiting machine performance—particularly equipment stability and ride quality. For 15 years, a new concept has been under development that seeks to rectify these performance issues. The concept is known as Low Sidewall (LSW)—a design that has proven effective in the automotive market.
[h2]AUTOMOTIVE INSPIRATION[/h2]
Only a few decades ago, 15-inch rims were the standard in the automotive market. Today, the same vehicles come standard with 18-, 19-, and even 20-inch rims.
This lower profile design improves ride quality, vehicle stability, and handling. So, why not apply the concept to industries like construction, where vehicle stability is a real challenge?
That’s the opportunity that Maurice “Morry” Taylor, CEO of Titan International, foresaw in the late 1990s. Shortly thereafter, he put the company’s engineers to work on the industry’s first off-the-road (OTR) LSW—a wheel/tire assembly for skid steers.
[h2]ENGINEERING THE LSW[/h2]
Making a viable LSW skid steer tire/wheel assembly required it serve as a replacement to existing standard skid steer tire/wheel assembly. The tire diameter, section width, inflation pressures, and load capacity must remain identical, all while reducing sidewall size and increasing rim diameter. Doing so required a three-stage research and development (R&D) process.
Finite Element Analysis (FEA): Building an LSW tire requires significant reconstruction of the shoulder and bead area to accommodate a larger rim. Working backward through the FEA process, engineers plug in the desired measurements of the tire and test the design under scenarios of varying weight loads and inflation pressures. Design adjustments are made until the desired results are achieved.
Prototyping: The first prototype requires a new steel mold be built to accommodate the larger rim. Once the tire is constructed, it is cured in the new mold and prepared for lab testing. LSW tires vary in cure time when compared to standard tires. Thus, it’s essential to test the composition of the rubber after a prototype is cured. If necessary, adjustments to cure time are made.
Field testing: Titan conducts testing of LSW tires in three ways, often simultaneously: testing internally at the company’s bull wheel facility, testing by OEMs at their individual testing grounds, and field testing by end users. Results are compiled for months, or even years, before the decision to launch an LSW product is made.
[h2]EARLY MOMENTUM[/h2]
From 1997 to 1999, Titan conducted testing of the LSW concept for skid steers, receiving excellent performance feedback from both OEMs and end users. Tests showed the LSW tire consistently outperformed standard tires in equipment stability, ride quality, and handling. Shortly thereafter, Caterpillar Inc. engaged Titan to produce Caterpillar-branded LSW skid steer tires.
What followed was a slew of Titan LSW product introductions from 1999 to 2002, including LSW backhoe tires, telehandler tires, and a variety of LSW tires for recreational and agricultural applications—each showing the same positive test results as the skid steer tires. Despite the OEM recognition, full-scale industry adoption proved challenging.
[h2]EARLY ADOPTION CHALLENGES[/h2]
One of the major reasons no other off-highway tire manufacturer jumped on the LSW bandwagon—and still hasn’t—is because building an LSW tire requires building a wheel to match. As the only manufacturer of both wheels and tires for off-highway markets, Titan seized its opportunity. However, OEMs were hesitant to source a product that no other tire manufacturer could provide replacement for in the aftermarket.
Thus, OEM adoption lagged and so did Titan’s momentum of LSW product introductions. Yet, the R&D and testing behind the concept remained strong, and Titan waited for the right time to once again move full-speed-ahead.
[h2]THE LSW RESURGENCE[/h2]
From the late 90s to present day, equipment has continued to grow larger and more powerful.
As bucket sizes, lift heights, and overall machine weights increased, new challenges in terms of equipment stability arose, including road loping, machine bouncing, and reduced breakout force— largely due to the flexing of the large sidewall in standard tires. In 2011, Titan once again undertook an extensive R&D, testing, and product introduction effort. The time was right, and OEMs took notice.
In 1991, Caterpillar Inc. introduced the world’s largest wheel loader—the Cat 994H. Since then, the Cat 994H has been enhanced with maximum payload of 38 tons, bucket capacity of 47 cubic yards, and an extended bucket lift reaching beyond 23 feet. In 2012, it became apparent the standard tire design was inhibiting performance on the new loader. Caterpillar turned to Titan to make the world’s largest tire in an LSW design. Titan took the standard bias 53.5/85-57 and reengineered it as a radial to fit a 63-inch rim, making it a 58/80R63 LSW—the new standard for the Cat 994H.
Titan’s momentum continued into a full expansion of its LSW offering, and in 2014, the company launched a complete line of LSW sizes for nearly every application, including skid steers, backhoes, graders, wheel loaders (small, medium, and large), and articulated haul trucks—each field tested with positive results.
[h2]LOOKING AHEAD[/h2]
The concern over single-sourcing may remain a road block to industry-wide adoption … at least initially. However, just as Caterpillar recognized the necessity to rethink tire design, others are sure to follow. With a continued trend toward larger equipment, it’s not a matter of if, but when LSW will be adopted by other OEMs.
Until then, Titan is going direct to end users, offering programs through dealers to make the switch to LSW an easy one.
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For More Information Johni Francis has been with Titan since 2006 and has held numerous roles, including an R&D engineer, a field engineer, and field engineering manager. Now acting as global product manager, Johni has played an instrumental role in the development of LSW wheels/tires for the construction and mining markets. For more information, visit www.LSWadvantage.com.
Modern Contractor Solutions, MAY 2014
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