A steering wheel is a steering wheel, right?
Not quite, especially when you put as much thought into steering-wheel design as a Lexus engineer.
Lexus’ latest leap in steering-wheel technology is a bamboo-trimmed steering wheel, which is an option on the 2013 GS 450h. Bamboo, as many Lexus fans have noticed, is gaining more and more traction in Lexus components, largely because the engineering teams keep finding ways to use this sustainable material to help improve the Lexus experience (think better speaker performance, thanks to bamboo diaphragms, in the CT 200h).
Lexus “Meister” Shuichi Ozaki developed this new wheel’s meticulously designed shape, as GS Chief Engineer Yoshihiko Kanamori explains: “After attaching pressure-sensitive material to his hands in order to measure stress points on the wheel, Ozaki could see which points of the wheel were being held most strongly, and sand down those sections. Now, wherever you grip it, there’s very minimal stress for your hands.”
“When you’re comfortable at the wheel, you don’t feel as tired even after a long drive,” agrees Ozaki. “I designed this wheel to help give the driver a sense of security.”
After a long and exhaustive development, Ozaki eventually pronounced himself satisfied with the shape. With typical Lexus thoroughness, he then revisited every other steering wheel parameter in search of further improvements. That resulted in a repositioning of the wheel towards the rear of the vehicle, an adjustment of telescopic range by 11 percent, and a two percent change in its angle.
“That last one might seem pretty minor,” he says, “but you wouldn’t believe the difference it makes.” Even the stitching has been recessed so that it doesn’t interfere with grip comfort.
But it’s the optional bamboo-trimmed steering wheel, a world-first, that really grabs the attention. In fact, the choice is a perfectly logical combination of science and sensibility. Bamboo is dense and stable. It’s also highly sustainable: some varieties can grow by 100 centimeters a day. Lexus-grade bamboo takes between three and four years to mature, still more than 10 times quicker than the 40 to 50 years taken by conventional woods.
Manufacturing the steering wheel is a challenging and very human-intensive process. Automotive wood specialists Miroku Techno Wood are based in Nankoku, in the Kochi prefecture of southern Japan. They handpick bamboo trees for longitudinal splitting on a radial-blade cutter. These split sections are whittled down to form thin slats.
After stress-processing and drying to achieve the exact moisture content, a stack of fillets is placed on a jig, laminated together using a high-frequency adhesion machine, and bent into a half-lifebelt shape.
Four of these rough half-circle laminates are wrapped around either side of the top and bottom sections of the steering wheel “skeleton,” where they’re hand-planed, worked, and sanded into smooth tubular forms.
Final polishing to achieve Ozaki’s ideal cross-sectional shape is done by hand. It’s a highly skilled operation, tackled only by craftspeople with the right level of experience. The final gloss stage delivers a gentle texture, perfect driver feel, and a well-deserved “thank you” for your hands.