Nowadays, ultralight doesn’t mean sacrificing protection in the mountains.  Our English friends at Rab have introduced a new shell called the Spark which offers bomber backcountry protection in a startlingly light, mountain-oriented package.

Rab Spark Jacket Features:

  • Helmet-compatible hood with wired peak and kitty clip roll-down closure
  • YKK AquaGuard® front zip with internal storm flap and rain drain
  • Napoleon mesh lined YKK AquaGuard® zipped chest pockets, left side doubles as integrated stuff sack
  • Velcro® cuffs
  • Hem drawcord
  • Weight: 11 oz
  • Size tested: Medium
  • Fit: Regular
  • MSRP: $200.00

Rab Spark Jacket Review

Spark is Light and Strong

Rab’s gear tends to be very technical with little interest in anything else; the Spark totally embodies their design ethos by including all of the necessary alpine features while packaging it in an unapologetic technical aesthetic.  The overall cut of the jacket is very similar to the Rab Myriad we covered earlier this year and, if its anything like its older brother, the Spark has very high expectations to live up to.  I’m 5’11”, 180 pounds and the tested size Medium fit very well indeed.

The Spark’s foundation is Pertex’s Shield+ fabric – I’ll just give it away now, but I was really impressed by its performance.  It’s woven with a tremendous amount of inherent flex and it disappears while climbing.  Waterproofing and breathability is always tough to quantify precisely, but I’m going to lay things out simply for the sake of the review; Shield+ is waterproof with an emphasis on breathability and a slight decrease in durability.

Rab Spark Jacket Review

Waterproofness is measured in labs by a fabric’s hydrostatic head (HH), which is basically how much pressure water needs to penetrate a fabric.  Shield+’s HH is around 20,000mm while something like Gore-Tex Pro sits around 28,000mm.  While water will have a harder time penetrating the Gore fabric, Shield+ is well above the 5,000mm that is considered waterproof in practical use. Pertex compensates for its lower HH by applying a truly phenomenal water repellant coating that is so hydrophobic that even chocolate syrup dripped off of the jacket – it’s so strong that it reminded me of this popular video.  The result?  Our Spark’s Pertex fabric is going to breathe like a champ while staying uncompromisingly waterproof.  I stood under a strong shower for around ten minutes just to be sure and no water made it through, even at the seams.

Rab Spark Jacket Review

Stains and spills just bead right up.

I mentioned that the Pertex sacrifices a touch of durability in pursuit of breathability, but that’s mostly an academic statement at this point.  I’ve had around six weeks to test the Spark thus far and, as I always do when testing gear, I intentionally abuse the fabric with friction and punctures.  I’ve rubbed the fabric harshly against granite and some very sharp calcium formations and I’ve snagged the fabric while crossing barbed wire fences.  Somewhat to my amazement, there hasn’t been a single failure anywhere on the jacket, no matter how much abuse I dished out.  That being said, I still would not bring this jacket into a multi-day mountaineering situation.  It’s just so darn light – sure, it’s completely waterproof and breathes very well but I would save the Spark for day trips above 12,000 feet or multi-days below 10,000 feet, depending on the degree of climbing you’re encountering.  It’s just too light to be a true mountaineering shell.

My testing ran through the gamut of my outdoor pursuits – I bouldered, climbed, biked and backpacked in the Spark to get a thorough idea of the piece’s capabilities.  Overall performance in aerobic conditions was on-par with the best fabrics out there – the fabric is highly resistant to wetting out, though the weather never really sent me any true rainy days to test it as thoroughly as I’d have liked.  My best testing occurred at high elevation, though, and the low relative humidity helped the jacket to shine; I only sweated it out once, and then it was only under my watch band.

Rab Spark Jacket Review

Easy access to the front chest pockets.

Rab’s careful construction and generous features list make the Spark a climber’s best friend.  All of the zips are sealed, including the two mesh-lined Napoleon pockets which double as vents.  I was particularly impressed by the sealed zipper which pulls and disengages very easily and has a double storm flap on the inside.  The noggin is protected by a stowable, fully-adjustable, helmet-compatible hood that features a wired peak that can stand up to just about any wind.  The jacket is cut reasonably long for good butt coverage, so it also sits and stays comfortably beneath a harness.  Naturally, the cuffs and hem are adjustable by Velcro and elastic pulls respectively.  To tie everything off, this 11oz lightweight packs into its left Napoleon pocket and disappears inside of a pack.

In practice, the Spark is just as delightful to wear as the Myriad was, albeit in a rather more utilitarian fashion.  The Pertex’s stretchy properties and the overall cut of the jacket help it disappear as you reach for holds or start working hard while pedaling.  Rab cuts their sleeves rather long and roomy and, while that aids in range of motion, I found that the sleeves flapped annoyingly in high-wind situations if I wasn’t wearing many layers beneath the Spark.  Rab’s commitment to saving ounces was such that they neglected both a zipper garage and a fleece chin guard, so the area around the face can be a little uncomfortable at times.  When I got aerobic in the jacket I was easily able to control my climate with the main zip and Napoleon vents and the fabric negates the clammy feeling that similar jackets suffer from.  When I bike I sweat like a hog, but the Spark was able to handle it with the proper ventilation.

Rab Spark Jacket Review

A little more posed than I hoped, but you get the deal.

The Good

  • Pertex Shield+ is a winner in the ultralight/breathable category
  • Fit and range-of-motion are among the best available
  • Special water resistant coating beads up water (or syrup) like nothing else
  • Lightweight and stows into pocket

The Bad

  • Too light for hard-core mountaineering
  • No zipper garage or fleece chin guard
  • Zippers came creased from storage and took a lot of wear to flatten out

The Bottom Line: Rab Spark Jacket

You can pick up this shell for just $150 at Moosejaw – that’s a steal.  It has the cut of a true mountaineering jacket and, if you only do light alpine climbing, this jacket would be ideal.  For people like me who are more likely to find themselves bouldering, top-roping, backpacking or cycling this jacket offers as much protection as I’d ever need.  Rab continues to prove themselves as one of the premier manufacturers of technical outerwear today.

Buy Now: Available from

About Author

Kevin Glover is an outdoorsman living, climbing and biking in Spokane, WA. Originally from the Nevada high desert, he moved to the PNW for its mild winters and allergen-free summers. He has guided throughout the Cascades and Enchantments for Peak 7 Adventures.

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