Review: UltrAspire Speedgoat Pack


Basic summary: A dual bottle waist pack designed by ultrarunning legend Speedgoat Karl Meltzer to carry gear and fluids in ultra-distance events without the weight or complications of a full vest. The pack combines two body-contoured 18.5 oz (550 ml) bottles with three storage pockets and tie-down straps on the front belt to manage fluids and cargo. The ride is impressively stable compared to other dual waist packs, but you’ll have to be fairly minimalist on the gear side to tote everything you need for an ultra.

MSRP: $80


  • Product Weight: 7.6 oz
  • Fluid capacity: 37 oz
  • Two soft-sided 550ml UltraFlask bottles included
  • Angled bottle holsters for easy access
  • Water resistant central rear zipper pocket
  • Right side zipper pocket
  • Left side elastic pouch
  • Lightweight mesh paneling
  • Speed hook belt clip for easy on/off
  • Dual removable quick access straps on front belt for poles or large jackets
  • Waist sizes adjustable 26”– 42”


Deep dive:

The UltrAspire Speedgoat was introduced this summer, and is named for Speedgoat Karl Meltzer, who played an integral role in its design and development. The idea was to create a pack that provided decent fluid and cargo capacity without detracting from your ability to run fast.

Meltzer advocated a waist belt model for two primary reasons: 1) weight is carried most efficiently at the waist, and 2) access to bottles and compartments is easier on a belt than on a hydration pack. The trick, though, was to make sure the added bulk and weight around the waist could be held in place securely; other dual-bottle belts or waist-mounted hydration packs have a nasty tendency to bounce and shift around too much.

UltrAspire accomplishes this successfully through a number of design elements. First, material construction of the Speedgoat is kept to a bare minimum; the interior surface is a very lightweight and highly breathable mesh, the pockets are thin nylon ripstop, and even the bottle holster insulation is just a few millimeters thick. Second, the curved rectangular shape of the bottles rests nicely against the small of your back and is much less inclined to movement than traditional round bottles. Finally, the front belt and speed hook keep the entire pack cinched down easily and comfortably.

Having dual bottles is ideal if you like to have sports drink or soda in one container and water in another. The total fluid capacity of 37 oz is about halfway between a traditional single bottle waist pack and a vest-mounted hydration reservoir; it’s probably enough to get you between aid stations in favorable conditions, but if it’s a hot day or there’s a long stretch between aid, it’s not quite enough unless you’re as fast as Speedgoat Karl. The bottle openings are wider than a flask but not as wide as standard bottles; they are generally easy to fill either from a pitcher or a press-down valve on the large capacity water containers typically found at aid stations.

Cargo capacity is also in the “decent but not great” category. The water-resistant center zip pocket is the largest, and you can probably cram a pair of gloves or beanie into it, but it’s not big enough to compress a jacket into. The side pockets will stash a headlamp or iPod or a few gel packs. Any larger equipment like a jacket or poles needs to be strapped in front, which makes them convenient to access but a bit cumbersome to run with until you get accustomed to it. One apparent oversight we’d like included on future versions is the lack of a key clasp in any of the pockets.



The UltrAspire Speedgoat is a very comfortable, stable, and highly functional pack that provides a nice middle ground for fluid and cargo capacity that is larger than standard waist packs but less than hydration vests. It’s also a great option if you like to manage separate types of fluids throughout a race. Although UltrAspire markets this as adequate for any ultra distance up to 100 miles, most of us who aren’t as fast as Speedgoat Karl will probably find a “sweet spot” for this pack in the 50K to 100K range.


About Author

Donald is a physical therapist, California native, barefoot aficionado, and father of three with more than 25 years of experience in endurance sports. He was a collegiate rower at UCLA, then dabbled in marathons and Ironman-distance triathlons before falling in love with ultras in the early 2000s. His favorite locations to run include Marin County, CA, and the Sierra Nevada mountains, and he loves exploring America's National Parks. When he's not training for ultramarathons, he enjoys hiking or slacklining with his family in Monterey County, CA.

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