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Game Changer : Gore-Tex Giro Jacket

Gore-tex Giro cycling jacket
James Spender
14 May 2015

What did people do before the Gore-Tex jacket? They got wet

If the holy trinity for bicycles is stiff, light and comfortable, the equivalent for cycling clothing is waterproof, windproof and breathable. Today many garments claim such properties, but 30 years ago there was just one: the Gore-Tex Giro Cycling Jacket. ‘At the time there was no existing jacket like the Giro,’ says Gore’s Gert Friedgen. ‘It was breathable, windproof and waterproof, with that special cut for cycling, a short front and long tail, and it was lightweight enough to be packable. But you could say it was down to a bit of luck it ever got made.’

The history boys

PTFE (polytetrafluoroethylene) – the basis for Gore-Tex’s ePTFE (expanded PTFE) – was discovered quite by accident in 1938 by Roy Plunkett, a scientist at US chemical company DuPont. During his research into refrigerant gases a once-charged canister of tetrafluoroethylene gas mysteriously lost its pressure, yet weighed the same as when it was filled. Intrigued, Plunkett cut open the canister to find a slippery, wax-like substance. Further investigation revealed that under high pressure, with the iron in the canister acting as a catalyst, the gas had polymerised to form a new substance – PTFE, latterly branded Teflon in 1945, and used in non-stick frying pans.

Fast forward to 1969 and WL Gore & Associates was using PTFE tape to make insulation for electronic cables. Bob Gore, son of founder Bill, was experimenting with cords of PTFE, seeing how far they could be extruded. On one occasion Bob gave a quick, hard yank to one of the heated cords. As if by magic, it stretched five-fold, yet remained the same diameter. Analysis of the cord showed it had become porous, to the tune of more than a million pores per square centimetre. ‘This porous nature is the key to Gore-Tex’s function,’ says Friedgen. ‘Each pore is roughly 1/20,000th the size of a droplet of water, which means water can’t permeate the material, but the water vapour from sweat can.’

It’s a neat trick, but initially the company didn’t see the application in the outdoors market. Instead, Gore-Tex was used in a variety of industrial applications, including in the cables in Neil Armstrong’s lunar module. ‘A German named Heinrich Flik had come over to study in America and ended up working for Bill Gore,’ says Friedgen. ‘He liked to cycle, and realised there was a garment missing that would allow riders to cycle comfortably in different weather conditions. It was that and his knowledge of WL Gore’s new material that encouraged him to make the Giro Cycling Jacket.’

Gore-Tex as a material couldn’t do it alone, so Flik set about creating a more durable laminate fabric – a backing liner and outer layer of charmeuse that sandwiched a Gore-Tex membrane ‘that was 0.02mm thick, a third as fine as a human hair’, adds Friedgen. From that fabric a sporty-cut jacket was constructed, with taped seams, a rear pocket and even, in the early version, a crotch strap: ‘It was to wrap the extended tail of the Giro underneath the rider to shield them from the elements. However we soon realised it was a potential hazard as it could get caught up on the saddle and cause crashes, so it was dropped.’

Strap or no, the Giro Cycling Jacket was a hit in Flik’s native Germany, although it was initially a tough sell. ‘Everyone we showed it to loved it,’ Friedgen adds. ‘But there was the price. At the time the most expensive jackets were 70 German Marks [£80], but ours was 200 [£230]. So Flik offered them to retailers on a commission basis, and within a month we’d sold 300.’ As one ad for the jacket said, ‘I like it, I bike it.’ Turns out we certainly did.

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