"Faster, higher, stronger” is the Olympic motto. It’s also the underlying philosophy behind the $25 billion U.S. sporting goods industry.

Sports equipment comes in all shapes and sizes. The diverse industry includes bicycles, camping gear, fishing tackle, fitness equipment, hunting rifles and scopes, kayaks, scuba gear and diving equipment, and skis. Of course, there’s also shoes, clothing and protective wear, in addition to various types of balls, bats, boards, clubs, racquets and sticks.

Unlike other types of consumer products, sporting goods have two unique market niches: professional athletes and amateurs who engage in sports for leisure. Cutting-edge products developed for professionals often trickle down to weekend warriors. And, the competitive industry readily adapts technology from other fields, such as automotive, aerospace, medical devices and consumer electronics.

“There are two sides to each niche market within the sporting goods industry,” says Phil Anthony, P.E., president of Design Integrity Inc. “Each sport has a segment that’s driven by low cost, using traditional materials. There’s another portion that’s driven by performance and favors materials that have higher strength-to-weight ratios.

“Product development efforts typically focus on making products stronger or lighter weight to create better performance or less strain on the body,” explains Anthony, who has designed bicycle components, golf clubs and other types of sports equipment. “Life cycles for sporting goods are getting shorter and shorter.”

“First and foremost, sporting goods need to perform,” adds Curt Anderson, president of Compass Product Design Inc. “Unless a new item performs better than an old product, it has a tough time breaking into the market. But, if it does perform better, it can revolutionize a market overnight.”

“Innovation is very important in the sporting goods industry,” notes Anette “Peko” Hosoi, a professor of mechanical engineering at the Massachusetts Institute of Technology (MIT). “Manufacturers are always pushing to develop new products and get new things on the market every year.

“Compared to other industries, sporting goods are not as regulated,” adds Hosoi. “That helps drive innovation in the sector.”

Three years ago, Hosoi and her colleagues from various MIT departments created STE@M (Sports Technology and Education at MIT). The organization works on projects that combine sports and multiple engineering disciplines, including aerodynamics, heat transfer, human factors, thermodynamics and vibration. Students and faculty have worked with a variety of sports equipment manufacturers on products ranging from kiteboards to skis.

One ongoing project involves high-end fishing reels manufactured by Okuma Fishing Tackle Corp. Engineers are attempting to reduce production costs by 50 percent on one of the company’s most popular reels to make it more appealing to consumers.

The MIT team recommended ways to make the product stronger and less susceptible to breakage by replacing some die-cast parts with plastic components. They also suggested ways to stiffen the spinner and make the reel more corrosion resistant.

Lightweight Materials

Sporting goods engineers covet lightweight materials that can enhance athletic performance and lower the risk for injury. Graphite, magnesium, titanium and advanced aluminum alloys are widely used in golf clubs, tennis racquets and racing bikes.

Plastics are also popular, because they are colorful and can be easily molded. For instance, nylon is used to make inline skates and bicycle components; polyamide is used for skis, snowboards, bindings and boots; and polyurethane is used for shoes and skates.

However, sporting goods manufacturers can’t get their hands on enough carbon-fiber composites. The material is popular for bicycle frames, fishing rods, golf shafts, snow skis, surfboards, tennis racquets and other products because it offers compression and lateral stability, as well as light weight, strength and durability.

“Carbon-fiber composites have taken over the sports world in a big way,” claims Kim Blair, vice president of operations at Cooper Perkins Inc. “They allow engineers to create optimal strength and stiffness in key locations.

“A lot of rigidity in sporting goods is governed by tube shape and wall thicknesses,” adds Blair, who has been involved in designing baseball gear, bicycles, golf clubs, helmets, running shoes, wearable sensors and other products. “Composites allow us to create more complex shapes and contours.”

Manufacturers of skis and bicycles have been pushing the envelope with composite designs. According to Blair, that’s one reason why the shape of downhill skis today is totally different than it was a decade ago.

Flexing properties in skis are crucial because of both compression on the top side and tension on the underside. “Recent improvements in ski design and performance have been enabled by advanced materials and advanced manufacturing techniques,” Blair points out.

In fact, engineers at Head NV recently teamed up with Audi AG to develop a carbon-fiber ski that weighs 200 grams less than comparable models. That allows it to be incredibly maneuverable and agile on the slopes.

Carbon fiber encloses layers of aluminum and titanium, as well as a wood core. That combination of materials allowed engineers to achieve optimal stiffness while also minimizing torsion, which is the twisting of the ski along its longitudinal axis.

The bike industry has also pioneered lightweight materials. Mass-produced bikes typically use low-cost, steel frames and lots of plastic components. However, high-end racing bikes depend on carbon-fiber composites, magnesium and titanium.

“Traditionally, steel and aluminum bike frames are welded together from multiple parts,” says Blair, who is a mechanical engineer. “Carbon fiber allows manufacturers to consolidate components and end up with a lower part count.

"Fifteen years ago, a bike used in the Tour de France race was 20 pounds," notes Blair. "Today, you can go down to your local bike shop and buy something that weighs just 15 pounds."

While composites have traditionally been used to make frames, the material is slowly finding its way into wheels and other bicycle components.

In fact, engineers in England recently reinvented the wheel by applying carbon fiber technology. Unlike a traditional spoke wheel, their "loopwheel" features an integral suspension system.

There are three "springs" in each wheel, which work together as a self-correcting system. The spring configuration allows for torque to be transferred smoothly between the hub and the rim.

Carbon-fiber composites originally developed for aerospace applications are also now flying around on football fields. Boeing Commercial Airplanes and Russell Brands LLC are working together to incorporate excess carbon fiber from the 787 Dreamliner to produce football shoulder pads.

The aerospace-grade material provides a high strength-to-weight ratio and greater durability. In addition, it’s thinner, stronger and 10 percent lighter than traditional composites. That provides an increased range of motion and a more secure fit for running backs, wide receivers and other athletes.

Engineers at Bauer Performance Sports recently spent more than two years developing a new line of lightweight hockey equipment. By using carbon-fiber composites, they created skates that are more than 30 percent lighter than conventional products. That allows professional hockey players to move faster and save more than 1,000 pounds of lifted weight over the course of a regulation game.

Bauer engineers also developed a protective body suit that is more than four pounds lighter than traditional equipment, which increases mobility. And, unlike traditional materials used in protective equipment, the high-end foams and composites can be customized to each individual player.

Embedded Electronics

One of the biggest trends changing the way that sporting goods are designed and assembled is wearable electronics. Products embedded with sensors and microchips can measure everything from heart rates and speed to exertion and arm movement. Paired with analytical software, the devices allow athletes to monitor and improve their performance.

The convergence of electronics and sports is attracting interest from both start-up companies and large industry players. For instance, a small firm called Arccos Golf LLC has just launched a product that features a set of 14 sensors that are attached to the ends of golf club grips.

Once paired via Bluetooth to an iPhone app, the system seamlessly integrates with a golfer’s game. The sensors capture critical data and provide instant access to information, such as distances hit and driving accuracy.

Sony Corp. recently unveiled a sensor that fits on the handle of tennis racquets made by several leading manufacturers, including Prince and Yonex. It features vibration analysis mechanics that analyze various player movements, such as shot count, ball impact spot, swing speed, ball speed and ball spin.

“Through highly sensitive wave and motion detection, the sensor can pick up multiple swing types, such as topspin forehand, slice forehand and volley backhand,” says Tyler Herring, vice president of product development at Prince Global Sports. “By allowing players to analyze their game with advanced data collection tools, we believe that the racquet selection process [will] become much easier.”

One of the largest players in the industry, Wilson Sporting Goods Co., is also developing new products that incorporate high-tech tools. In fact, it recently licensed wireless motion sensor technology developed at the University of Michigan. Wilson plans to use the inertial sensors in its line of football and tennis products.

“We are in the midst of a digital onslaught that we believe will revolutionize training and the athlete’s toolbox,” says Mike Dowse, president of Wilson. “We’re focusing development on sensor-enabled products that deliver data to the athlete for analysis and training to help them play and perform better.”

The sensor technology was developed by Noel Perkins, a professor of mechanical engineering at Michigan and an avid fisherman who was trying to improve his fly-casting technique. By embedding wireless inertial sensors in his fly rod, Perkins discovered that he could record an enormous amount of useful information—up to 6,000 pieces of data per second. His lab also developed algorithms that interpret those pieces of data that are of most interest to athletes and their coaches.

“The data allows a rich understanding of performance that has never been achieved before,” claims Perkins. “Even when using high-speed film and video, athletes and coaches lack some of the data this technology provides, including important metrics of performance, such as acceleration, spin axis and spin rate.

“Besides athletic training, the technology can help match sports equipment to the athlete and to evaluate athletes for scouting and recruiting purposes,” Perkins points out. “Instead of just relying on game statistics, this technology could be used to quantify performance in an objective way.”

“Smart sporting goods are going to be a huge market,” predicts MIT’s Hosoi. “Many manufacturers are interested in integrating sensors into existing products and looking at ways to create new niche products.”

“However, the cost of electronics has to be relative to the value added,” warns Cooper Perkins’ Blair. “Power is the biggest challenge that must be addressed. Engineers also need to be careful that they don’t destroy the performance of a piece of equipment when adding electronics to it.”

New technology being developed for military applications, such as augmented-reality displays and exoskeletons, could eventually find their way into sporting goods. In fact, Hosoi believes there will be a convergence between military applications and sporting goods within the next few years.

“There’s a synergy between advances the military is making today and innovations in the sports tech arena,” says Hosoi. “They are both geared toward advanced human performance.”

Assembly Challenges

Sports equipment is assembled with a wide variety of joining processes, including adhesive bonding, mechanical fastening and ultrasonic welding.

For example, golf club manufacturers rely on several types of adhesives. “The head and shaft are typically bonded together with a two-component epoxy that requires a long cure time,” says Jim Victoria, Eastern regional sales manager at Nordson EFD. “Static mixers are used to mix and dispense the two components.

“It’s a very labor-intensive process,” says Victoria, who has worked with several leading manufacturers of irons, putters, woods and other types of golf clubs. “Cyanoacrylates have been used in the past, but they’re too brittle for many applications in the industry.”

“Double-sided adhesive tape is used to attach grips to shafts,” adds David Thomas, production manager at Fishman Corp. “Water-based tape is often used so that the grip easily slides onto the shaft.”

Epoxies are also used to assemble baseball bats, bike frames, bows, arrows, canoes, tennis racquets and other sports equipment. On the other hand, badminton shuttlecocks are assembled with hot-melt adhesives.

Ultrasonic welding is used to assemble plastic sporting goods ranging from fishing lures to ping-pong paddles. “Applications today require a very high quality of weld performance while maintaining visual [appeal] for the consumer,” says Jeff Frantz, director of ultrasonic business development at Branson Ultrasonics. “This can be very challenging and requires collaboration during the development stage.”

According to Frantz, ultrasonic welding is ideal for assembling sports equipment because it’s “a fast process that can be easily adapted to a wide variety of applications and can easily be automated.”

 As demand for wearable sporting goods increases, ultrasonic welding may become more popular. “The parts have more curves, due to ergonomic demands, and can include elastomer soft-touch materials where the parts contact the body,” notes Uwe Peregi, executive vice president and general manager at Herrmann Ultrasonics. “Wall thicknesses are shrinking, [which forces] us to be more creative in our joint design approach.”

Fasteners are typically used to assemble sporting goods that rely on mechanical components, such as bicycles and fishing reels. But, they're also used in football helmets and other protective gear.

"If a product will be assembled overseas, we try to use more screws and fasteners, because it's more economically feasible," says Design Ingegrity's Anthony. "However, we usually try to use the least amount of fasteners and include snap-fits whenever possible."