Soichi Hirayama is responsible for developing the C3fit technology incorporated in Goldwin’s high-performance base layer collection. He had always harbored an idea: If only there were a pair of socks that could support the soles of the feet like taping, it would enhance the athlete’s performance in sports. As a rugby player of 15 years since high school, and thereafter as an ultrarunner who takes part in 100-mile trail races, Hirayama has been rough on his legs and particularly his feet. He knows from firsthand experience the importance of the foot’s arch structure, which plays the crucial role of a suspension. The accumulation of fatigue causes the plantar muscles to stiffen, reducing the suspension function and making the knees and lower back susceptible to damage from the impact of landing. This shaped Hirayama’s belief that socks are as important as shoes, if not more important, for covering the athlete’s soles. But while the market presented all kinds of high-tech shoes, it did not offer any innovative socks.
“In that case, I’ll make them myself—high-performance socks that can withstand a 100-mile race.”
Hirayama enlisted the help of Taiko Co., Ltd., engaging in the integrated production of knitted garments, from planning to development to manufacturing. Since its founding some 70 years ago in Nagano Prefecture, known for a thriving silk industry, Taiko has honed its expertise particularly in socks.
“We asked for a cross taping function to support the entire arch structure—comprising two longitudinal and one transverse arches—and protect the feet from the impact of landing. Plus, we didn’t want the socks to feel tight under any conditions.”
Realizing both a unique cross taping function and not-too-tight comfort—this was a challenge for Masaru Kuroiwa, manager of the manufacturing department at Taiko. For many years, he has been the driving force behind Taiko’s advanced knitting technology. But Hirayama’s request had even Mr. Kuroiwa at his wit’s end.
“The greatest feature of knitted fabric is elasticity—its ability to stretch both lengthwise and crosswise—and form a perfect fit. The question was how to get the knitted fabric to defy its own nature and provide compression. There were plenty of socks on the market that claimed to have a taping construction, but when I actually tried them on, none of them provided the supporting effects of taping.”
Mr. Kuroiwa set his eyes on fusible bonding yarn. When heat is applied, the yarn stiffens and holds its shape. It is ordinarily used in knitted products to secure the stitches and prevent unraveling. Mr. Kuroiwa’s idea was to knit this fusible bonding yarn into tuck stitches, which reduce elasticity, and create a taping effect.
“The degree of stiffness needs to be adjusted through the yarn itself. So I asked the yarn mill to make fusible bonding yarns in various stiffening rates, and went about knitting sample after sample. The people at the mill were certainly perplexed. No one uses such a tremendous amount of fusible bonding yarn!”
It took a year of going through samples that were uncomfortable to wear or that provided insufficient support to arrive at a compression level that satisfied Hirayama. The completed product was C3fit Arch Support Socks with a taping construction from the tip of the metatarsal bones, at the ball of the foot, to the sole. Goldwin Inc. holds patent rights for the structure that supports the two longitudinal and one transverse arches. A pile construction is used for extra cushioning in the heel and toe areas of the sole, and a strong yarn provides reinforcement in the easily torn tip of the toes. The short socks are designed with a raised tab to alleviate discomfort caused by the shoe opening rubbing against the achilles tendon. Not only are the socks high-performance, but with polyester recycled from PET bottles used in the body, they are also environment-friendly, testifying to the attention to detail paid by Goldwin and the Japanese specialty manufacturer.
The project had no limits and was driven solely by a desire for the “best sports socks.” It ended up holding a special place in the hearts of the professionals at the knitted products manufacturer.
“Creating something new is fun and it gives us motivation at the production site. Hirayama and our staff shared the passion of creating a good product, so we were able to collaborate and work toward a common goal. Goldwin Inc. also requires its suppliers to practice significantly high levels of quality control, so we had to look into new processes to meet their demands. Consequently, we were able to improve our own levels of quality control, too.” (Kuroiwa)
As a signature product of Goldwin with C3fit technology, the socks packed with brand’s meticulous care and attention to detail have been favored among athletes. Socks are small but an important item. Each of the many functions and technologies incorporated in a single pair represents the many hands the product has passed through, the high level of technological expertise at Japanese factories, and their commitment to their crafts.
“Production sites where seasoned artisans vigorously practice their art—we hope to see them live on into the future in Japan. And we at Goldwin hope to keep up our own craftsmanship in order to support that.” (Hirayama)
