Big Agnes Zoom UL

The Big Agnes Zoom UL uses a dimpled baffle pattern. The dimples are not deep or tall, so the pad does not provide as much pressure relief as pads like the REI Helix or the Sea to Summit Ether Light XR. The Zoom UL is still much more comfortable than pads with horizontal baffles like the Therm-a-Rest XLite NXT.

The Zoom UL is 8.3 cm (3.3 in) thick, with 8.9 cm (3.5 in) outer chambers. Big Agnes builds the two outer chambers slightly larger than the inner ones so that the sleeper stays centred on the pad. The pad is thick enough so that, when sleeping on my side, my hip and shoulder do not touch the ground. The top material has no stretch and is not soft. Stability when fully inflated is good due to all of the connection points between the top and bottom of the pad with the dimpled baffling; which results in maintained stability when deflating the pad for improved pressure relief. The Zoom UL is a good pad for back sleepers and decent for side sleepers.

Overall, the Zoom UL is more comfortable than ultralight pads of a comparable weight but is not a pad to choose if you prioritize comfort.

The Big Agnes Zoom UL has an ASTM-tested R-value of 4.3 and Big Agnes rates it for extended three-season use. The Zoom UL uses two layers of reflective film inside the pad for insulation, but the film is loose and ends up sagging to the bottom of the pad. In sunlight the sag is visible through the outer fabric. The Zoom UL is effective at insulating from the ground but, with the top and side of the pad exposed to the surrounding air with no insulation, colder air temperatures can have a significant impact on warmth. Another factor that affects warmth is that each weld point has a hole through the insulation and each of those holes acts as a channel for heat loss to the ground. The pad kept me warm down to 3°C (37°F) on warm ground.

Overall, the warmth of the Zoom UL is disappointing. The Zoom UL is not the warmest pad in its class even with an R-value of 4.3 and the pad is at its worst when the air temperature is low. I rate the Zoom UL as a purely summer pad.

The regular Big Agnes Zoom UL weighs 400 g (14.1 oz) on my scale, which is very close to the advertised weight of 397 g (14 oz). The regular wide has an advertised weight of 482 g (1.1 lb). Big Agnes calls the Zoom UL its lightest insulated air pad. For an ultralight three-season pad, the Zoom UL’s weight is low. Only two pads come close to competing with the Zoom UL on weight, the Therm-a-Rest XLite NXT and the NEMO Tensor All-Season. The XLite is warmer and lighter, with an advertised weight of 370 g (13.1 oz) for the regular, though it is a mummy shape. The Tensor All-Season is warmer, heavier, and more comfortable. Big Agnes gets the weight down through what it calls O-beam internal construction, which uses less material inside the pad than a conventional baffle, and through a thin post-consumer recycled nylon ripstop shell and reflective film insulation rather than heavier synthetic fill.

The Zoom UL also packs very small because of the thin materials it is made of and the reflective film insulation. The regular packs to about 10 cm (3.9 in) by 20 cm (7.9 in).

The Big Agnes Zoom UL has a single valve, not a two-way valve. The valve is a single port with a flap inside. The valve itself is well placed, sitting flush in a top corner of the pad within easy reach of a sleeper - so adjusting the inflation level of the pad while lying on it is easy. Inflation through the valve is difficult because the included pump sack is too small and too stiff to be useful. The valve size is also not compatible with most electronic pad pumps.

Deflation is also difficult because the valve cap has to be tucked into the rubberized part of the valve, which creates a small gap for the air to leave through. The air does not leave quickly, so rolling the pad up and putting it away takes more time and effort than it should.

I also think that pushing a piece of rubbery plastic into the rubberized valve could lead to wear and early failure. Big Agnes does include a replacement valve seal in the box, which helps but does not solve the underlying design issue.

The top and bottom of the Big Agnes Zoom UL are 20-denier recycled ripstop nylon. Big Agnes uses what it claims is aviation-grade TPU lamination coating on the inside of the pad to create a leak-proof air chamber. Every pad is inflated and tested at the factory before it ships and each pad ships with a repair kit and a spare valve seal.

I have had no durability problems with my pad so far. There are over 150 reviews on Backcountry.com with most issues involving the valve. There are many reports of slow leaks due to valve failure, even when the pad is brand new.

Big Agnes has a lifetime warranty for defects in materials and workmanship.

The two components of a sleeping pad that usually lead to the pad sounding noisy are the internal insulation (reflective film can sound crinkly) and the outer material (which can squeak on tent floors). The Big Agnes Zoom UL uses reflective film insulation and it is moderately noisy, leading to some crinkle sound when shifting positions on the pad. The outer material has a plasticky texture and can also be noisy when moving on tent floors. Overall, the Zoom UL is a noisier than average pad.

The Big Agnes Zoom UL excels at weight, packability, and comfort. The compromises are warmth, which is well below what the R-value would predict, and a valve that makes deflation slow and may not last. The Zoom UL is for the sleeper who prioritizes weight, wants more comfort than a Therm-a-Rest XLite NXT without the weight of a NEMO Tensor All-Season, and camps in summer conditions.