UltrAspire Big Bronco Race Vest

• Lightweight 12 litre capacity: Combines substantial ultra-running storage with a pack weight of approximately 205g.
• Accessible 4x 500ml soft flask carry: Two 500ml soft flasks can be carried at the front and two in the rear Fluidic Holsters, keeping all four within reach while wearing the vest. Soft flasks are not included.
• 2 litre reservoir compatible: Dedicated reservoir storage provides capacity for a reservoir up to 2 litres. Reservoir not included.
• Expandable rear compartment: 4-way stretch construction expands for larger loads while allowing the compartment to lie flatter when lightly loaded.
• Guided rear access: Soft foam flare helps guide the hand towards the rear compartment opening.
• Organised rear storage: Divided accessible pockets and gusseted construction provide additional capacity and separation.
• Front stretch storage: Four 4-way stretch mesh pockets provide accessible equipment storage.
• MaxO2 closure: Shock-cord sternum system allows natural chest expansion while helping maintain a secure fit.
• On-the-move pole carry: Z-pole attachments can be accessed from either side while wearing the vest and also provide compression around the Fluidic Holster compartments.
• UltrAcool Light Mesh: Lightweight breathable mesh helps move moisture away from the body.
• Sweat-resistant security pocket: Zipped storage against the back helps protect smaller items from moisture.
• Water-resistant construction: Silicone and PU-coated lightweight nylon helps resist water, abrasion and tearing.
• Sweat-proof webbing: Resists absorbing moisture and becoming heavier when wet.
• Soft edge binding: Microfibre polyester edging reduces abrasive contact against skin and clothing.
• Reflective detailing: Front and rear details provide additional visibility in low light.

Measure around the chest while wearing the clothing you expect to use with the vest. The three size ranges overlap, providing scope to select the fit around both chest measurement and the clothing normally worn underneath.

The MaxO2 closure uses stretch cord across the chest to allow expansion during breathing while maintaining tension against the body.

For information about UltrAspire running vests and hydration packs, see our UltrAspire pack guide.

If you are deciding how much carrying capacity you need, see our Running Backpacks, Race Vests & Hydration Packs Guide. Capacity should be considered alongside mandatory kit, aid-point spacing, water availability, weather, pace, access to crew and your preferred carrying strategy, rather than race distance alone.

If you are unsure about sizing, hydration setup or whether the Big Bronco provides the right capacity for your ultra-running kit, get in touch for straightforward advice.