FIND YOUR PERFECT JACKET
THE SECRET TO STAYING DRY IN ALL CONDITIONS
The cycling climatologists amongst you will know this already, but the average UK temperature during the winter of 2018/2019 at 5.2°C, 1.4°C above the 1981-2010 average. Rainfall measured 256mm, a whopping 77 per cent above the 1981-2010 average. So mild and wet, making the apparel industry’s Holy Grail of a fully waterproof, fully breathable jacket that much tougher. ‘What,’ you might exclaim? ‘According to the marketing gumph, my jacket’s already achieved both.’ In reality, we’re far from a dry, warm and airy nirvana. But it’s not all overcast gloom. Material technology and greater awareness of fit is such that the fabled boil in the bag jackets are a thing of the past, as long as you know what to look for. Which is where we come in…
Damp Ratings
When it comes to both waterproofing and breathability, there are standards albeit not necessarily cycling-specific. Let’s start with waterproofing. There are numerous different protocols but most involve the equivalent of placing a 1in x1in square tube over the fabric and determining how high (in millimetres) a column of water you can suspend over it before it starts leaking. Broadly, 0-5000mm offers little resistance; 6-10,000mm is rainproof and waterproof under light pressure… right up to 20,000mm-plus, which is rainproof and waterproof under very high pressure. Simple? No.
“That standard comes more from the outdoor industry where you’re sitting on waterproof trousers, causing significant pressure on the water beneath,” explains Steve Smith, brand manager of the European arm of Castelli. “Cycling’s a different experience as the pressure’s not the same from the force of rain or water flicked up from the wheel in front. In some markets, 10,000mm is deemed waterproof. It’s only a gut feeling but I’d say 4000mm, or four bars of pressure, is ample for cycling purposes to call a garment waterproof.”
Many manufacturers include this waterproof rating in the jacket description. As a snapshot, Sportful’s Stelvio jacket measures 20,000mm, while Endura’s top-end Pro SL Shell is around 15,00020,000mm, says Endura’s brand manager Ian Young. But, as Young continues,
deflecting the water’s no good if you can’t let it out. That’s where breathability rating comes in.
“It’s a similar test to the waterproofing one,” Young says. “You take a 1m2 piece of fabric and see how much water passes through it in a 24-hour period. The higher the number, the more breathable a material is. Our Pro SL comes in at around 40,000g/ m2/24hrs. The problem is, it’s hard to compare jackets with this scale because few use it or publish the results.”
With good reason, says Castelli’s Smith. “It’s just not accurate. Take a polyurethane membrane. It’s a stretchy, rubbery material, almost like plastic wrap that you’d use in the kitchen. Moisture won’t flow across the membrane but polyurethane is hydrophilic so will absorb moisture. The problem is, when it’s [saturated], a fair amount of moisture will start to evaporate. In a cycling context, that 24hour test can suggest a material is more breathable than it actually is.”
Waterproof means waterproof… maybe
Though both ratings are imperfect, they’re a starting point. But there are further labyrinths to negotiate in search of the ultimate jacket, namely semantics. “It’s not as bad now but I remember some brands – certainly American brands – calling a jacket waterproof if the material was waterproof,” accuses Young. “The problem is, that didn’t necessarily mean the seams and zipper were waterproof.”
All dressed up but no-one to sew. In a waterproof fashion anyway. So nefarious goings on but, in the era of reader reviews and ratings, you’d hope misinformation is confined to the past. In the present day, every credible apparel manufacturer spends much of their R&D budget in search of an outer later that keeps you dry. But that’s not easy, especially in specific moisturestimulating scenarios, like ascending 8 per cent gradients against driving rain.
“It’s really not easy. You see, when it comes to waterproofing, complete protection would derive from something completely impermeable like a fisherman’s jacket,” says Simon Hodder, senior lecturer in ergonomics at Loughborough University who specialises in textiles and extreme environments. “But it’s neither flexible or breathable. The nearest you have to a gold standard is a Gore-Tex-type material that’s waterproof but permeable.”
Ahhh, Gore-Tex. Who hasn’t glowed with pride when proclaiming that their jacket’s spawned from Gore-Tex. But what is it about Gore-Tex that makes it, at least in outdoor clothing circles, so revered? You can’t look beyond heritage and its ability to evolve. Would you believe, Gore-Tex celebrated its 50th birthday this year, an anniversary that might never have happened if it wasn’t for a stroke of luck…
In 1969, after a series of failed experiments, American scientist Bob Gore grew frustrated and gave a hard yank to a rod of polytetrafluoroethylene (PTFE, more commonly known as Teflon) that he’d heated up to 300°C. His act of irritation resulted in a material that stretched to about 800 per cent its original size, forming a microporous structure that was 70 per cent air but was retaining its hydrophobic properties (it’s those properties why Teflon’s often used to coat non-stick pans). Bob Gore had inadvertently invented expanded PTFE (ePTFE), introduced to the public under the trademark Gore-Tex. Its breathable, waterproofing properties transformed an industry.
Popularity of shake dry
Since then, leading cycle clothing manufacturers have continued to turn to Gore-Tex. They trust the product, as do consumers. It’s why both Castelli’s Smith and Rapha’s communications manager, Jess Morgan, signpost us to their respective Idro Pro 2 and Pro Team Lightweight jackets as their most waterproof. They both contain Gore-Tex’s new Shake Dry technology.
“Shake Dry dispenses with traditional woven outer fabric and instead exposes the ePTFE membrane as the outer surface of the jacket,” explains Morgan. “This approach has two distinct advantages. It removes the bulk and weight of the face textile [the fabric facing the elements] plus, as ePTFE is inherently hydrophobic, the outer surface of the jacket sheds water and stays dry without the need for additional DWR chemistry.”
We’ll come onto DWR treatments shortly. But first, Smith elaborates on why, certainly in Rapha and Castelli’s eyes, Shake Dry has
Simon Hodder Senior lecturer in ergonomics at Loughborough University “When it comes to waterproofing, complete protection would derive from something completely impermeable like a fisherman’s jacket. But it’s neither flexible nor breathable”
shaken up the industry. “Many jackets employ three layers – in fact, we have models like this ourselves – but the problem is when using a Teflon-like membrane in the middle of a three-part construction, you need to somehow glue it on either side and stick it to another fabric. Every time you bond it to a material, you lose breathability.”
What it lacks in insulation, it makes up for in breathability, Smith opines, saying its element-deflecting properties are such that he’ll wear it around 90 per cent of the time in dry conditions. He also enthuses about the fact that it scrunches up to “half a rear pocket”. “There’s a Pro version, too,” he continues, “designed for the guys at Team Ineos.” With the Ineos soigneurs on hand, Castelli’s extended the tail, added internal pockets, and adding stretch zones throughout the arms and elbows. It’s more durable and “perfect for UK riding”.
Constructing comfort and warmth
Three cheers for Shake Dry, echoes around the Rapha and Castelli offices. Competitors like Endura would dampen down those cries, of course, with Young highlighting
that many of the Scottish company’s materials are proprietary, meaning the mills weave the fabric with the specific properties required by Endura, rather than them utilising off-the-shelf fabrics like Shake Dry. “That means we can achieve the waterproofing, breathability, weight, durability and feel of the fabric we want,” says Young. “But all of that is redundant,” he continues “if we don’t construct it to the demands of a cyclist.”
Key to construction is waterproofing where each piece of fabric meets, namely the seams and zipper. Hodder picks up the story. “Most jackets will be stitched, which clearly means you end up with little holes where the needle’s punctured the material to sew the thread. To remedy the situation, manufacturers will bond a stretch of waterproof tape to the inside. That said, some jackets dispense with stitched seams and simply bond the pieces of material together. As far as I’m aware they’re okay but I’m unsure how durable this is.”
“The zipper’s another area of water ingress,” Hodder continues. “That’s why many zips will have a rubber encapsulation around the zip teeth like you might have on a diving bag.” Castelli’s Idro jacket employs a zipper from YKK called Off-Guard, which is weather-resistant rather than waterproof. “That’s where the cycling-specific nature of things comes in,” says Smith. “Because of your upper body leaning forward, you don’t experience too much direct water hitting the front of your jacket. That’s unlike commuting where you’re more upright and rain’s hitting you face on. I felt strongly that we needed a zipper that’s easy to open and close because people are constantly opening and closing zippers, ventilating when they can. If up a hill, opening up; closing on the downhill. Hence, the choice of Off-Guard.”
It’s clear the cycling-specific nature of jackets, marrying waterproofing with breathability, demands compromise, none more so than for the fidgets amongst us. On hoods, hit drops, back on tops, out of saddle, in saddle, stretching out lower back, reaching for the water bottle… “It’s true that most of the stretch waterproofs aren’t as good as the non-stretch versions,” says Young. “That’s because you’re opening up the pores. It also means any coating applied to the jacket won’t work as well because it’s an open structure. Something like the Pro SL Shell utilises a mix of fabrics. It’s predominantly non-stretch with some specific stretch panels, so balancing a slight loss in waterproofing but with a better shape.”
Endura aren’t the only ones. The Idro applies stretchy Gore inserts at the elbow, shoulder and side panels. These aren’t Shake Dry. Most manufacturers do the same; in fact, the side panels are one of the most important areas of any jacket. Because they’re tucked away from the heaviest of downpours, it’s a fertile area to increase venting, usually from a wider-pored material.
“Some jackets even have zip vents beneath the armpits,” adds Hodder. “You can then take advantage of the airflow to remove the moisture you’re generating inside.” Endura produced such a jacket in collaboration with Brompton, though it’s more for commuters than roadies.
Layered to perfection
Much of this waterproofing-breathability overview’s seen in isolation, but manufacturers must view things in situ. A normal off-season setup will comprise a base layer, cycling t-shirt or jersey and said jacket. A base layer’s close to the skin for optimum wicking – drawing moisture from the body to the environment – with the next layer on top and then the jacket. Rapha’s Morgan argues a “slimmer-fitting jacket maximises breathability”. Endura’s Young concedes they’ve gone down the slimmerline route in recent times, but base-layer levels aren’t required.
“It’s better for temperature regulation and to prevent condensation to have a little bit of room,” he says. “But even more important to a jacket’s breathability – and this is something out of our hands, really – is the heat differential between the inside and outside of a jacket. If it’s a relatively warm and humid day, there’s little difference in the two environments.”
Smith puts it another way. “In essence, if it’s raining outside, it’s 100 per cent humidity. If it’s also 100 per cent humidity within your jacket, that means your breathability goes right down because osmosis struggles to take place.” It’s why Smith says that “our goal isn’t necessarily to stop every drop of water from coming in, as you’re going to be sweating from the inside
anyway. We want to make the garment as functional and comfortable as possible even if that means sacrificing some level of waterproofing”.
Outdoor clothing manufacturers have also sacrificed a level of waterproofing for more virtuous reasons, albeit enforced. “Because of EU laws against the use of fluorocarbons, we now don’t use these in our DWR treatment,” says Young. DWR, or durable water repellent, is a coating added to fabrics to increase water resistance and it’s used by nearly all manufacturers. “Ours are now more environmentally friendly but there is a drop in performance compared to the non-environmentally friendly ones.”
Still, Endura offers reproofers in spray or wash form, repeat application dependent on how often you use your jacket. This is an overlooked maintenance process and one you can simply determine by pouring water onto your jacket. If it fails to bead off, it’s time to reproof.
Which is all well and good up top but what about bib tights? Is it worth a quick spray of DWR? “No,” answers Young. “Keeping your legs totally dry isn’t the most important thing. Stretch is key. We used to produce a waterproof tight but it just didn’t stretch. You also need warmth so a brushed lining is the first thing you should look for in a bib tight.”
Young says you can achieve lower-limb waterproofing by slipping a pair of Endure
Adrenaline mountain-biking shorts over your bib tights, “albeit this is only applicable for long, rainy descents in the Alps”.
Instead, says Hodder, you should pay much greater focus on glove and skull choice. “Your extremities are a big driver of how uncomfortable you feel. Take your hands. They have such a high surface area to mass ratio that they lose heat quickly if you don’t protect them. This also affects dexterity, which is another big driver of discomfort.”
Which begs the question: if a bad jacket soaks you from the inside and no jacket soaks you from the outside, is it best to cycle as nature intended aside from a skull cap and pair of mittens? “It’s difficult to say where the comfort comes from,” Hodder politely replies!
Finding the right jacket for you must not only balance waterproofing and breathability, but your budget, too. The Idro Pro 2 from Castelli, for instance, while lauded by its users, comes in at £340. You also need a jacket that suits your riding needs. “In high-tempo situations, it’s better to work with semi-permeable fabrics that allow for better thermal regulation,” says Rapha’s Morgan. “We developed our Shadow technology [which lacks a membrane so increases breathability but retains a level of waterproofing] purely for these high-intensity rides.” Or you might prefer greater insulation in your jacket? Or a tight-fitting rain cape to minimise flapping? Or a long tail to protect your derriere? Whatever your needs, just remember that wading through the marketing hyperbole, there is a truth: that better breathability and waterproofing comes at a cost. Whether your needs demand a £300-plus solution, that’s over to you, your tolerant or unaware partner, and your bank manager.
Steve Smith Castelli European brand manager “Our goal isn’t necessarily to stop every drop of water from coming in as you’re going to be sweating from the inside anyway. We want to make the garment as functional and comfortable as possible even if that means sacrificing some level of waterproofing”