UltrAspire Big Bronco

The Big Bronco is sized based on your torso measurement, not your clothing size. Measure around your ribcage just below your chest; the Small fits 35-40 inches, Medium fits 38-43 inches, and Large fits 43-46 inches.

No, the Big Bronco is hydration compatible, but it does not ship with a reservoir or bottles. You will need to purchase your preferred hydration bladder or handheld bottles separately.

While designed for long-distance efforts, the 12-liter capacity is versatile enough for shorter runs if you need to carry extra layers, nutrition, or safety gear. Because of the ErgoFit harness, it stays stable even when not fully packed.

The MaxO2 system uses a shock cord that allows the vest to expand and contract with your breathing. You can easily adjust the tension on the fly to keep the fit secure without restricting your chest movement.

Yes, it is constructed from silicone and PU-coated nylon, which provides a good balance of durability and lightweight performance. It is designed to withstand the friction and snagging typical of trail running.

We recommend hand washing the vest with mild soap and hanging it to air dry. Machine washing can damage the specialized mesh and the integrity of the shock cord closure system.