Lightweight sleeping mat: Big Agnes Zoom UL: The most hyped lightweight sleeping mat put through its paces in a 7-night test

The requirements for sleeping mats for bike packers are not straightforward. They need to be lightweight, and of course their packed size should be as small as possible so they don’t take up too much storage space. But that’s not all: comfort and durability would also be a bonus. As is always the case, it’s rarely possible to avoid compromises entirely; the question is simply: how good is the compromise?

The The Zoom UL is Big Agnes’ lightest insulated air mattress – and on paper, it looks quite impressive. With an R-value of 4.3, it’s said to be suitable for three seasons; however, on frozen ground, Big Agnes recommends an additional foam underlay. Thanks to its larger outer chambers, the 3.25-inch-thick mattress reliably keeps the sleeper centred – no rolling off the edge during the night.

Inside, there are two layers of heat-reflective film and an O-frame construction, which keeps the weight and pack size compact. The single-valve system inflates the mat quickly and allows for fine adjustments to the pressure via a second mode. The recycled nylon ripstop outer material is designed to be robust enough for rougher use, whilst the TPU lamination in the seams ensures durability. An antimicrobial inner treatment is designed to prevent odours. Included in the pack: pump bag, storage bag, spare valve seal and repair patches.

We put the much-hyped Ultralight sleeping mat through its paces on a bikepacking trip and during overnight stays on a variety of surfaces.

Ultralight sleeping mats need to combine a number of features: they should be lightweight, compact and comfortable – and they should also be robust. Tip: To avoid pushing the latter to the limit, place a bivouac sack or your rain jacket underneath you on stony ground.
Laurin Lehner, BIKE test editor

Packed dimensions and weight

As a benchmark, we tested the Therm-a-Rest Ultralight sleeping mat (NeoAir) – which we know well and have been using for many years. Back to the Zoom UL. The sleeping mat is available in three sizes; for a height of 1.78 metres, we chose the smallest size, 20" × 72", and found it worked well for us. It offers plenty of space and is wide enough. Weighing 473 grams including the pack sack and inflation bag, the Big Agnes Zoom UL is a real featherweight. There are slightly lighter options, such as the Therm-a-Rest NeoAir (X-Lite NXT), but the Zoom UL is definitely within the acceptable range.

Inflating with a pump bag

Instead of inflating it by mouth, a pump bag is included. Once you’ve got used to it, the mat is fully inflated in about 10 pumps – without leaving you breathless. The pump bag can be easily pressed onto the sleeping mat’s valve. During the final few pumps, the valve may come loose due to high air pressure, in which case you’ll need to press it back on again.

Dozing off on the Zoom UL

At 9 centimetres thick and with plenty of air, the Zoom UL offers enough comfort to ensure a good night’s sleep. Compared to our benchmark ultralight sleeping mat, the Therm-a-Rest, the comfort level is roughly comparable. We were also impressed by the insulation, even though we tested the Zoom UL in warm temperatures on all but two occasions. The noise it makes when you toss and turn is perfectly acceptable. There’s nothing to complain about here.

​Update: The only point of criticism is unfounded

When it comes to packing the mat back into its stuff sack after a night’s sleep, there’s cause for criticism – or so we thought. Unlike a twist valve, such as the one on the Therm-a-Rest NeoAir*, this one features a flip valve. This means that to let the air out, you have to stick your finger into the valve and squeeze the air out manually. But there’s an easier way – we just didn’t think of it ourselves. User “Kate/Südbaden” kindly pointed this out to us in the comments section. And indeed: the valve cap can be inserted into the valve, allowing the air to escape without you having to use your finger at all. Thanks for the tip, “Kate/Südbaden”.

In a nutshell:

• Total weight: 573g (including case and carrying pouch)
• R-value: 4.3
• Packed dimensions: 21 x 10.5 cm
• Thickness: 9 cm
• Price: 200 euros (RRP) >> available here
• Materials: Post-consumer ripstop made from recycled nylon; 2 layers of heat-reflective film; inflatable cushion made from recycled cushioning material; TPU lamination

Conclusion:

The Big Agnes Zoom UL is rightly praised by other outdoor platforms. Its weight, pack size and comfort are excellent. It’s also easy to inflate using the inflation bag supplied. Whilst the price is high, it’s reasonable when compared with similar ultralight sleeping mats.