7 months ago

Dirt and Trail May 2020

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The science of riding

The science of riding gear: All about Gore Tex Fabric: By Jenny Smith. If you have a look at your Enduro jacket, MX boots or riding pants, chances are pretty good that you’ll see a Gore Tex label somewhere. We took a look at the people that make the stuff and how it all happened. What is GoreTex? Gore-Tex is a waterproof, breathable fabric membrane and registered trademark of W. L. Gore and Associates. Invented in 1969, Gore-Tex can repel water while allowing water vapor to pass through and is designed to be a lightweight, waterproof fabric for allweather use. W.L. Gore & Associates is one of those success stories of American ingenuity and innovation. Founded in 1958 by the husband-and-wife team of Wilbert (Bill) Lee — who had spent 16 years with DuPont — and Genevieve Walton Gore, the company got its start making wire and cable insulation before the couple’s son, Bob, made an accidental and extremely fortuitous discovery. In 1969, he was trying to stretch extruded polytetraflouroethylene (PTFE, otherwise known as Teflon) for use in plumbers’ tape, but no matter how gently he pulled, it always broke. Frustrated and down to his last few samples of test material, he grabbed one of the heated rods and gave it a hard yank — and to his astonishment it didn’t snap, it expanded. The company called it “expanded PTFE,” or ePTFE: with uses in everything from laptop computers to prosthetic arteries to astronaut suits…and, of course, waterproof motorcycle gear. Gore makes more than 300 different membrane types, and each finished product goes through more than 600 quality control tests — that’s before it 12 DIRT & TRAIL MAGAZINE MAY 2020 All Gore-Tex apparel includes a DWR (durable water-repellant) coating that sheds water from the outer fabric. Banks of washing machines agitate continuously for days, testing the durability of Gore-Tex apparel. Gore’s wet flex test machine puts Klim’s boots to the ultimate waterproof test. goes to the manufacturer, which in the case of riding gear means motorcycle-specific testing, including CE certification. There’s a biophysics lab that tests for comfort and acoustics (important for hunting and military gear), six rain rooms for waterproofness and an environmental room that goes from -50 to 50 degrees C (-58 to 122 F), 5% to 98% humidity and zero to 22 mph wind speed. Upstairs is a huge room full of washing machines that are used for wet flex and abrasion testing; they are stopped and the material tested every eight hours until it fails. At the Elk Creek facility we got a look at the glove and boot test labs, where Gore-Tex membrane booties are tested for leaks. A big machine in the corner subjects finished boots to a submerged wet flex test; Klim boots must pass at least 200,000 flexes without a leak before hitting the market. Gloves are probably the toughest item to waterproof, and every Gore-approved factory (which apparel partners must use) has a whole glove leak test machine. Klim uses a special Gore-Tex membrane insert with glue on one side that bonds it directly to the outer shell, and a soft Trica liner bonded to the other side for optimum control feel. Still, gloves are where most riders will say they’ve experienced waterproofing failure… The folks at Gore suggested that what we often think is a leak is actually either a lack of breathability causing moisture buildup or the waterlogged outer shell feeling cold against our skin, which our brain interprets as “wet.” Gore-Tex is only a part of what Gore does; its products are used in the medical, automotive, consumer electronics and aerospace industries, among others. Gore’s quality control testing includes six different “rain rooms,” where finished Gore-Tex apparel like this suit from Klim is tested in real-world conditions. This room includes a nozzle simulating riding at speed Our sensory system has no “wet” register, only temperature, and if the water is cooler or warmer than our skin we perceive it as “wet.” This is how sensory deprivation chambers work: by floating in saline water that’s exactly our body temperature, our brain registers no contact at all. To be comfortable, a piece of waterproof apparel needs to breathe and shed water. “Breathability” doesn’t mean airflow, however; it means the removal of warm, moist air from the body. This is what makes Gore-Tex apparel more comfortable than, say, wearing a plastic bag — it “breathes” while keeping you dry. As our Gore guide put it, “it’s not magic, it’s physics.” But as we noted above, if the fabric outside the Gore-Tex membrane is waterlogged your skin thinks it’s wet, so a DWR (durable water-repellant) coating is important. Every Gore-Tex-branded item comes from the factory with a DWR coating, and the instructions for keeping it in good shape might surprise you: throw it in the dryer. Yep, you should be washing and tumble-drying your Gore-Tex. The heat reactivates the DWR, so water will bead rather than soaking in. You’ll still need to reapply a new coating every few years, just make sure it’s silicone-free. When properly cared for — and assuming they don’t have an unfortunate meeting with the pavement — Gore-Tex products should remain waterproof for life. There you go! Don’t say you don’t learn stuff from motorcycle magazines!