BMW Designed a Badass Wheelchair for the US Paralympic Team
The wheelchair that Tatyana McFadden rode to one victory after another in the Paralympic Games this week looks a lot like the other wheelchairs on the track. But it is different in several subtle yet key ways, not the least of which is it was designed by engineers at BMW.
Yes, that BMW.
McFadden, who was born with spina bifida and paralyzed from the waist down, has won three gold medals in Rio and set a Paralympic record of 11 minutes, 54.07 seconds in the women’s T54 5,000-meter race. Her sleek racer, like all racing wheelchairs, is a low-slung tricycle with sharply cambered rear wheels and a front wheel stretched waaaay out front for stability at speed.
But a few interesting things set her racer apart. A carbon fiber frame provides greater stiffness—and therefore efficiency—than aluminum. Subtle tweaks to the chassis improve aerodynamics. And everything, from the cockpit to the steering arm to the gloves she wears—were designed specifically for her body, and how she sits in the wheelchair. BMW DesignworksUSA claims it cut aerodynamic drag by 10 to 15 percent.
Brad Cracchiola, an associate director at DesignworksUSA, says developing the wheelchair began with observing athletes as they train and race. His team made 3-D scans of the athletes and used software to identify where they experienced the most drag. They discovered that a lot of it didn’t come from their chair, but from their bodies. Athletes tend to adopt a specific stance while racing. Using the 3-D scans, Cracchiola’s team created custom molds of the athletes’ bodies to create personalized cockpits, leading to a more comfortable, more streamlined stance. “Athletes need to keep their lower bodies as firmly anchored to the chair as possible so they don’t waste any effort due to poor ergonomic positioning or shifting of their body during a race,” he says.
Designworks decided to to use carbon fiber instead of the more typical aluminum because the material can increase rigidity by as much as six times. A frame that isn’t as stiff absorbs energy, reducing efficiency. “We know these improvements help transfer an athlete’s power more efficiently into speed,” Cracchiola says.
Cracchiola says he can’t quantify any improvements the chair provides, largely because each athlete and each chair will perform slightly differently from one track to the next. But one thing is consistent—“One cool anecdote we heard from the athletes was that drafting behind the BMW chair is very hard,” he says. “Because of the improved aerodynamics of our design, the air flows more efficiently around our racing chair, so the athlete in the back is forced to push through the air as well.”
Cracchiola may not be able to quantify the chair’s performance benefits, but the US squad can. Athletes using the BMW racer have won three gold medals, three silvers, and a bronze while setting two Paralympic records.