Zippers are just a standard feature of daily life. Going up a hill in a shower? Zip up your waterproof jacket. Hitting the ski slopes? Unzip the ankle cuffs on your ski pants to adjust the buckles on your ski boots. These crafty fastenings have become ubiquitous in practically all clothing, and in outdoor gear they lend versatility and convenience, but unless they break, you probably don’t give them a moment’s notice.
Recently, however, I was on a hike with a group of journalists in the Lake District during the Kendal Mountain Festival. As part of the hike, we were all testing out the Jack Wolfskin Highest Peak waterproof jacket, which we all agreed was pretty great. It’s a hardshell jacket that’s amazingly soft, totally waterproof and breathable, which makes it an ideal outer layer for both cold and wet adventures.
One journalist told me the only thing he felt was missing was a two-way zipper – those zippers that you can unzip from the bottom as well as the top – and being one to think a lot about outdoor gear, well, it got me thinking. What is the point of a two-way zipper? And do we need them in outdoor gear?
When I got home, I had a look through my embarrassingly large pile of outdoor jackets to see if two-way zips are standard, and I just hadn't noticed. I found that they’re definitely not ubiquitous, at least among my extensive library of waterproof jackets, but I do have them on my Adidas Terrex Myshelter Gore-Tex Active Rain Jacket and my Mountain Equipment Makalu Jacket.
Likewise, they’re not standard across the board on my insulated and down jackets, except for my Fjällräven Keb Wool Padded Jacket. They are common among my ski jackets, such as my Helly Hansen Elevation Infinity 2.0 Ski Shell and I have one on my Houdini Power Houdi fleece jacket.
Taking a closer look at gear I’ve tested over the years, the pattern I’m spotting is that they’re most common among hardshells and ski jackets than lightweight waterproof jackets, fleeces and down jackets, and some companies such as Mammut, Vaude and Fjällräven tend to use them more than others. So are they necessary, and should you be looking for them in your hiking and skiing jackets?
What is the point of a two-way zipper?
A two-way zipper has several advantages over a regular zipper, especially when it comes to outdoor gear:
1. Easy access
If you set off on a hike wearing a fleece jacket with your phone and gloves in your hand warming pockets and it becomes colder or wetter than you expected, you’ll ideally pull on a shell jacket that you’ve been carrying in your backpack to stave off the wind and wet.
You probably don’t want to have to move everything from one set of pockets to the other, but after a while you might decide you want your gloves or phone – you can unzip the zipper on your shell from the bottom up and easily grab what you need from the pockets underneath, which is really convenient.
2. Better weather protection
The advantage of easy access to pockets doesn’t just provide you with convenience – it also means you get more wet weather and wind protection in a storm. Your shell jacket might have the best breathable waterproof membrane on the market, taped seams and waterproof zips, but it doesn’t do you much good if you keep unzipping it all the way down to access gear underneath.
If the rain is blowing straight at you full pelt, it only takes seconds for your mid layer to get soaked, which doesn’t make for comfortable hiking conditions. If you can just unzip a few inches from the bottom up, it means you get to stay drier, even in the worst weather.
3. Enhanced breathability
A really good outer layer should be made from breathable material, so that if you’re doing something highly aerobic in very cold conditions, or in wet weather, you don’t have to choose between weather protection and getting sweat-soaked. However, any layer that’s waterproof isn’t going to be completely breathable, so it’s handy if it comes with features like pit zips, to help you dump heat. You might also just unzip your jacket, but if you’re like me, you hate a cold wind around your neck and chest, so with a two-way zipper, you can vent a little around your midriff instead.
4. More comfort when sitting
The reason my long parka has a two-way zip is because it comes down to my knees, and without it, it could be uncomfortable to sit down. I don’t recommend hiking in long coats because you need room to bend your knees, though I suppose if you're going on a winter hike and it’s all you have, the two-way zipper makes life easier.
Generally speaking, a proper hiking jacket will come down to your hips and be higher in the front than the back, so it should pose too many issues when you stop and sit down for lunch, especially if it has an elasticated hem and fits properly. However, it is possible that by the time you layer it on over other various pieces of clothing, it all gets a bit pinchy, and with a two-way zipper, you can be a bit more comfortable.
Do I need a two-way zipper on my hiking jacket?
As you can see, a two-way zipper on a hiking jacket like a shell or fleece can definitely add some versatility and primarily, it makes it easier to reach gear without unzipping your entire jacket, which is really more important if you’re hiking in rough conditions, skiing or sailing.
For really extreme conditions, it could be a good thing to shop for, but needless to say for regular hiking you can get by without it and it doesn’t need to be a deal breaker. I should also note that features like zips do add weight, so if you’re looking for a really light waterproof jacket, like my Montane Phase Lite, you may well have to sacrifice the wonders of a two-way zipper.
How to use a two-way zipper
Just bought yourself a jacket with a two-way zipper and having trouble getting the hang of it? Just place both zippers together at the bottom of your jacket, then slide the free zip edge completely into both sliders securely – you should hear a soft click. Then simply hold the bottom slider and pull the top slider up as far as you want.
During your hike or ski day, you can pull on either slider to unzip from the bottom or the top. At the end of your adventure, make sure the bottom slider is all the way down before unzipping from the top to remove your jacket.
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Julia Clarke is a staff writer for Advnture.com and the author of the book Restorative Yoga for Beginners. She loves to explore mountains on foot, bike, skis and belay and then recover on the the yoga mat. Julia graduated with a degree in journalism in 2004 and spent eight years working as a radio presenter in Kansas City, Vermont, Boston and New York City before discovering the joys of the Rocky Mountains. She then detoured west to Colorado and enjoyed 11 years teaching yoga in Vail before returning to her hometown of Glasgow, Scotland in 2020 to focus on family and writing.