UltrAspire Big Bronco Race Vest – Desert Sage (Medium) with 2x500mL SoftFlasks

Overview

The UltrAspire Big Bronco Race Vest is engineered for runners who value balance, hydration flexibility, and a close-to-body feel. Developed in collaboration with UltrAspire elite ultramarathoner Jeff Browning, this vest prioritizes lightweight performance without compromising on practical features. The design aims to minimize bounce and maximize reach, so your pace and terrain confidence stay intact from start to finish.

Key design highlights

• ErgoFit: refined geometry supports precise movement and stable weight distribution, aligning with natural biomechanics.
• 12 L total capacity with a front-harness layout built from 4-way stretch mesh; compatible with a 2 L reservoir for longer outings.
• Bottle compatibility: supports UltraFlask 550, Formula 250, Human 20 oz 2.0, wL Reservoir 2.0, or collapsible bottles (bottles not included).
• UltrAcool Light Mesh back panel reduces bulk and heat buildup; a soft foam flare guides hands to the main compartment with ease.
• Sweat-proof back pocket provides a secure space for valuables and quick access on the move.
• Max O2 Form fosters unrestricted breathing while maintaining pack stability through a stretchy, rebound-friendly cord system.

What you might feel on race day

• Flexible hydration options on the fly with the possibility of carrying a 2 L reservoir for longer runs.
• A lightweight, breathable feel even when the vest is fully loaded, thanks to the UltrAcool mesh and balanced weight distribution.
• A secure, race-ready fit that minimizes disruption during pace changes, climbs, and quick tempo shifts.

Why this vest stands out

Designed for endurance use in real-world conditions, the Big Bronco emphasizes practical features over gimmicks. Expect improved refill access, smoother transitions, and a focused rhythm on challenging sections, without overpromising results.

Care and fit notes

Medium sizing corresponds to 38"-43" chest/torso. Materials are chosen for endurance wear, quick drying, and comfortable airflow. For care, rinse with mild soap and air dry away from direct heat. Desert Sage provides a subtle, race-ready appearance for training and events.