The Big Agnes Fly Creek UL25 is a light bag and packs down small for multi day trips and for carrying high into the hills.

The Big Agnes Fly Creek UL25 has a gently tapered mummy profile but hides some interesting features in that silhouette, most obviously in the centre, half-length zip entry. I find this design very good at camp, allowing full upper body movement while still staying partly in your bag.

Peter Macfarlane highly recommends

The Big Agnes Fly Creek UL25 lofts extremely well and warmth feedback against bare skin is immediate.
Pros
  • comfort
  • warmth
  • weight
Cons
  • centre zip not for everyone
Quick specs
Price: $499.95 | £499 long (available from Big Agnes)
Weight: 788g (long)
Fill: 482g of 850 fill Downtek™ PFC-Free
Shell: Ultralight recycled NetPlus® 10D nylon ripstop
Construction: Signature Diamond quilt-through top | box baffled sides and bottom
Zip: ½ length centre
Length: 210cm, 225cm
Rating: 2°C comfort, -4°C limit
Sizes: regular and long
Unisex
bigagnes.com

The zip runs to just below the waist and has a large down baffle behind its full length. It has a regular-style small zip which runs pretty snag free. The hood is quite minimalist and more like the hood of a down jacket but still has a down filled baffle around the face and a baffle around the shoulder and the back of the neck. There’s also a draw cord to cinch the whole hood right in. The rear of the bag is a more standard box wall format and the top of the bag is a quilted stitch-through construction.

The stitching is in a repeated diamond shape which is designed to hold the down in place. I was initially concerned that stitch-through construction on the surface of the bag most exposed to the open air would lead to cold spots, but as a side sleeper I noted that the diamond filled baffles press up against one another, closing any gaps. I haven’t noticed any particular areas of heat loss. The foot box is well shaped and well filled with down.

The Big Agnes Fly Creek UL25 is a light bag and packs down small for multi day trips and for carrying high into the hills. Credit: Peter Macfarlane
The Fly Creek UL25 packs down small for multi day trips. Credit: Peter Macfarlane

The nylon shell is made from re-cycled fishing nets and is very soft and smooth against the skin. On the outer shell, water resistance is initially good but if spills aren’t dried or if there is more prolonged contact, some absorbtion will occur.

The Big Agnes Fly Creek UL25 lofts extremely well and warmth feedback against bare skin is immediate. It’s a light bag and packs down small for multi day trips and for carrying high into the hills.

How Peter tested

Peter Macfarlane slept in the bags in the same woodland bothy over winter, using the same sleepmat to achieve consistency, and at wild camps in spring. He is a size large, 6 foot (180cm) tall and tested long bags. The bag’s outer shells were tested for water resistance to spills and condensation by applying clean water and light pressure. See how it measures up to others on the market in our guide to the best sleeping bags.

This review was first published in our wild camping kit special issue.