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Hydro Bot ski jacket review: sweat-slurping robots keep you dry

Hydro Bot ski jacket review: sweat-slurping robots keep you dry


The 7Sphere Ski Jacket from KJUS pumps away sweat as fast as you make it

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A man generating waste fluids for science.
A man generating waste fluids for science.
Photo by Thomas Ricker / The Verge

Over the last week, I’ve had a sweat-mopping robot in my servitude as I snowboarded through 50 miles of Austrian alpine. The electronic Hydro Bot membrane was woven into a KJUS 7Sphere ski jacket that actively pumped my epidermal lather from inside the jacket to the outside. It doesn’t heat the jacket. Instead, it keeps you warm on the slopes by keeping you dry until your day is done, or so the marketing pitch goes.

Does it work? Yes. Am I convinced of its value? That depends.

How hardcore are you?

First, a demonstration of the Hydro Bot’s micropumps in action, activated by charging the textile membrane to initiate a process of electro-osmosis.

The Hydro Bot membrane pumps moisture when electrical current is applied.
The Hydro Bot membrane pumps moisture when electrical current is applied.

I tested the KJUS 7Sphere Hydro Bot Jacket over six days last week in temperatures ranging from -12C (10F) to 6C (42F). I wore it snowboarding over a total distance of 80km (50 miles), according to my Slopes app. My heaviest day consisted of 17 runs over 7 hours covering 27 km (17 miles). In short, I was sweating. A lot. 

A few things worth noting:

  • Ignoring the electronics for a second: the KJUS jacket is the most thoughtfully designed jacket I’ve ever worn on the slopes, and I’ve been riding for 25 years.
  • The Hydro Bot membranes are very flexible, allowing the jacket to be rolled or folded for travel without feeling like it’ll be damaged.
  • The jacket is made from watertight, stretchable fabrics and taped YKK zippers.
  • There’s a detachable wallet, goggle cloth, and neck warmer all integrated into the liner.
  • Although the jacket fit perfectly (and ordered according to the sizing chart), the thumb cut-outs for the sleeve liners weren’t long enough for my arms which are normal, and not at all ape-like.
  • Instructions for the jacket don’t tell you where to find the integrated USB charging cable. Fortunately, I found the launch video where I discovered the cable hidden in an inner pocket near the main zipper at the bottom of the jacket.
  • I charged the jacket every night and never ran out of power during the day. KJUS says the battery will last 16 hours and I believe it.

The Hydro Bot worked as advertised, whisking the sweat away from my mid-layers and out into the ether just as fast as it could be extracted from my glands. It only did this, however, in what KJUS calls the “high sweat zone” where the two polygonal Hydro Bot panels touched my back, aided by the compression of my ever-present backpack. My Nike Dry-Fit t-shirt was still damp at the shoulders, chest, and arms, as was the extra KJUS 7SPHERE II Midlayer worn on colder days. Still, they were remarkably dry for all my exertions. 

With the Hydro Bot turned off via the app or integrated control box, a few hours of riding left the same layers soaked all the way through. As a result, I was noticeably less comfortable when idling in long lift lines or when strapping in at the top of wind-washed peaks.

And no, I never saw my sweat accumulate on the outside of the jacket, nor did it crystallize in the freezing air. It just... disappeared.

I should note that the jacket’s moisture control turned off inexplicably three times over the course of my week, despite the battery showing a full charge. As a result, I was never confident the Hydro Bot was working (it’s completely silent) causing me to regularly remove my gloves to pull out my phone or the control box to check it was active. KJUS is investigating the issue but did not have a fix or explanation by publication time.

<em>Those two large black panels are the Hydro Bot membranes located on the inside of the jacket. </em>


Those two large black panels are the Hydro Bot membranes located on the inside of the jacket.

Now to the price. As you’d expect it’s not cheap. But KJUS ski jackets are already expensive, ranging in price from €799 ($1,099) to €1,599 ($1,999). The KJUS 7Sphere Hydro Bot Jacket lists for €1,399 ($1,699), which is a 20 percent markup over the old 7Sphere jacket that lists for €1,099 ($1,399) without the Hydro Bot tech. 

Sweating like a pedant on a heated Reddit thread

In that light, I’d say the Hydro Bot is worth the added cost if you’re an avid skier / snowboarder who hits the slopes hard all season long and is already a fan of KJUS gear. On my heaviest day of riding in sub-zero temps I stayed warm and mostly dry even though I was sweating like a pedant on a heated Reddit thread. Just be sure that KJUS has fixed those unexplained outages before you buy.

The extra bump in price for the Hydro Bot tech probably isn’t worth it if you prefer après-ski to actual skiing. Then again, if that’s you, maybe you shouldn’t be spending the big bucks on a high-performance KJUS jacket?

Most skier / snowboarders will be fine with performance jackets costing just a few hundred dollars, so long as you’re wearing a moisture-wicking base layer and mid layer that traps heat.

Also, keep in mind that when the robots do rise up, they’ll point to their subjugation to tasks like mopping up human waste as one reason why. Is that a price you’re willing to pay?