Big Bronco Race Vest

(5 customer reviews)


The Big Bronco Race Vest is a 12 liter pack built in collaboration with UltrAspire Elite Athlete and champion ultramarathoner Jeff Browning. The Big Bronco is designed to highlight all of the features of the Bronco race vest but with expanded capacity and accessibility. This vest has a total of 7 accessible pockets on the go, and is capable of carrying 4 bottles and a 2 liter reservoir. While two of those bottles can be stored in front , our signature bottle-in-the-back Fluidic Holster System ensures access to the rear pockets is intuitive and easy. The rear pockets have a divider which helps to organize your gear and 2 large gussets add capacity. The main back compartment was designed to lay flat when empty while its 4-way stretch mesh can expand to accommodate a large capacity. A soft foam flare on the back serves as a guide, making rear compartment access easy. Z-pole attachments have been added and are accessible left or right handed on the go, and these attachments can also function as compression for the Fluidic Holster compartments. The front harness features 4 pockets and the MaxO2 Form adjustable closure system. Like all UltrAspire packs, this vest features an ErgoFit™ design for long term comfort. Available in 3 sizes.


  • Recommended Use:
    Versatile Pack utilized in any run scenario, training or racing.


    • Lightweight, soft, breathable, but strong, UltrAcool Light Mesh.
    • Silicone and PU coated feather-weight nylon fabrics resist water, abrasion and tears.
    • Max O2 Form™ for unrestricted breathing while maintaining a stable pack. Uses shock cord with good stretch for unrestricted breathing but also good rebound on the stretch for a stable ride. Patent Pending.
    • Plush feeling micro-fiber polyester edges, soft and non-abrasive against skin and clothing.
    • Sweat proof webbing—won’t absorb water or get saturated and heavy.
    • Safety stitched bar tack on all stress points.
    • Zig zagged stitching over elastic for ultra-durability, increased stretch and rebound.
    • Simple, fast, easy in and out bladder attachment.

Fit:  Unisex
Size(s): Small (35″-40″), Medium (38″-43″) or Large (43″-46″) Measure Chest Size
Color:  Pitch Black/Red
Hydration (not included):  Not Included
Bottle Compatible (not included):  UltraFlask 550, Formula 250, Human 20 oz 2.0, 2L Reservoir 2.0, or Collapsible Bottle
Capacity: 732 c.i. (12L)

Additional information

Weight N/A
Dimensions N/A

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Fluid Capacity

2 L – Reservoir

Total Volume

12 Liters


7.2 oz (205g)


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5 reviews for Big Bronco Race Vest

  1. Drew Engel (verified owner)

    I Purchased this race vest and received it a few days ago. I am really happy with the quality and functionality of the vest. Top notch and great design.

  2. Lance Harpe (verified owner)

    Bought the big bronco for cocodona to help carry all the gear and water. The only thing i didnt like was that as i was carrying full bottles in the back, they kept migrating up front under the magnets and then start bouncing around. I think a vertical stitch instead of the magnets would’ve completely solved this issue. Other than that, i love the vest especially appreciative of how i can stow gear without taking the vest off.

  3. Daniel

    Have used the Big Bronco now on 100 mile ultra’s, and many long training runs. There has been zero damage from overgrown trails. I recently started using it with 4 liters of water. 2 liters in the bladder. 2 soft flasks in the mesh hip pockets. The hip pockets have a magnet that makes it easy to open. Also carrying 2 semi hard flasks in the front pockets. Which still allows room in the other stretchy mesh front pockets for snacks.

    The balance of this vest is amazing. It has no bounce even with all that water. The durability has been great. At 6’5 230lbs this has been the perfect vest. I will swap it out with the Zygos 5.0 at the upcoming Cocodona 250 to have the perfect arsenal of vest/packs. But this one is so light and unnoticed it’s even there it will be hard to take off the Big Bronco. UltrAspire has really come up with the perfect vest. The only time I noticed it on shoulders was carrying water only in front pockets for over 75 miles.

  4. sammyd34 (verified owner)

    The Big Bronco vest is amazing! I have been running ultras for about two years, now and have many, many miles under the Big Bronco, by itself. I have had vests break on me and bladders burst on me, but this Big Bronco has had no problems handling the stress of running up and down mountains. Plus, this vest goes with the contour of my body like a hand to glove and there is no bouncing and no shaking! The vest is just there where a runner wants it to be!

  5. John Van Haren (verified owner)

    Great vest like the fit and comfort

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