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MontBell UL 90 and MontBell UL 120 Mats

Mini-review for the Lightweight Inflatable Sleeping Mats State of the Market Report 2011


by Roger Caffin and Will Rietveld | 2011-08-23 00:00:00-06

MontBell UL 90 and MontBell UL 120 Mats - 1
Both sizes of the MontBell UL Comfort System Pads.


This mini-review is part of Part 2 of our survey of airmats. We have two MontBell mats here from the UL Comfort System Pad series: the 90-cm and the 120-cm versions. They are traditional self-inflating foam-core mats. As the mats are both rectangular and only differ in the length, we have condensed the data for the two into one section. The photo here shows the two of them, stacked one on top of the other. In addition, we cover two other neat little Japanese add-ons which were provided. They were unexpected but definitely appreciated.

MontBell UL Comfort System Pad 90 and UL Comfort System Pad 120

MontBell UL 90 and MontBell UL 120 Mats - 2

Length 87 cm / 34.3 in 118 cm / 46.5 in
Width 50 cm / 19.7 in
Thickness 2.4 cm / 0.9 in
Shape Rectangular
Weight 315 g / 11.1 oz 428 g / 15.1 oz
R-Value 2.2 - 3.9
Drag Force 21/21 N
Insulation PU foam layer
Inflation Self
Larger Side Tubes No tubes at all
Material 40d non-slip nylon
Repair Kit Yes
Stuff Sack Yes
Price US$59 US$69


We have given just one graph of R-value here because, as mentioned above, the two mats are identical in construction except for length. The R-value is perfectly adequate for three-season use, which is what these mats are intended for. They are a bit warmer than, say, the Therm-a-Rest Prolite mats, but they are a bit heavier. When you normalise the R-values for the mass per unit length of the mat they cluster very closely with the other foam-core mats - which figures.


With a drag force of 21 Newtons (N) the MontBell UL Comfort System pads just manage to move up into the 'not too slippery' category (ie >20 N). However, they are much less likely to slip out from under you in the night for at least one reason - or two in some cases. The first is that they are definitely not as thick as the air-core mats, and this seems to make them more docile in the field.

Things get more interesting when there are two of you sharing a tent with the same mats. MontBell has very cleverly put holes in the edges at the corners, and you can use the holes with the little toggles they provide to link two mats together: loops are not needed! That makes the combination very stable. Alternately, as shown in the picture here, you can 'stretch' the mat by adding a pillow at the end using the same holes and toggles.

We also tested these with a Gossamer Gear 1/8" Thinlight mat on top: there was no sliding around between the two.

MontBell UL 90 and MontBell UL 120 Mats - 3
MontBell with pillow.

Comments by Will Rietveld

Janet and I tested the MontBell 90-cm and 120-cm sleeping pads and attachable pillow on three backpacking trips. While they are a few ounces heavier than the TaR Prolite pads, they are also more comfortable. The foam inside is apparently not die-cut, which accounts for the extra weight (and comfort). In contrast to the Prolite pads, I found the MontBell pads to be decently comfortable. The pads were warm on nights down to -1 C and -3 C (30 F and 28 F).

MontBell's attachable inflatable pillow (68 g /2.4 oz) is addictive. It attaches to the pad with toggles and loops to hold it in place, and it's just the right height to support my head. I leave it attached when packing it, so it's very convenient to use.

Overall, I find the MontBell sleeping pads and pillow very likeable for sleeping comfort; I just wish they were a bit lighter. Note that MontBell will be revising their sleeping pads for spring 2012, to be announced at summer 2011 Outdoor Retailer.

Comments by Roger Caffin

Of course, being only 2.4 cm thick you need to inflate these mats fairly firmly to keep you off the ground. But they are of comparable thickness to other self-inflating mats, and of comparable comfort. Yes, 6+ cm is nice, but we found these thin MontBell mats to be quite adequate with just a bit of care about clearing the ground of major lumps. And they were quite warm enough for three-season use.

We also tried them out on a lightweight trip in alpine country, sleeping on bumpy snow grass. I found that a firm inflation definitely help smooth the snow grass bumps out - I was even able to wiggle around to get my hip over the gap between two humps of grass. That worked fine.

MontBell UL 90 and MontBell UL 120 Mats - 4
MontBell on a cold night.

The alpine trip did show up a limitation of these mats. The temperature during the nights got down to -3 C, -3 C and -8.6 C (28 F, 28 F, and 16.5 F) according to my little recording data logger. That was a bit too cold for the MontBell mat - or perhaps the already frozen ground was too cold. So I put a 1/8" Gossamer Gear Thinlight pad over the MontBell mat to boost its insulation a bit. I doubt that the thickness dropped below 24 mm even under my hips, but the snow grass did help there. Anyhow, that worked just enough - and note that I was using a Katabatic quilt on the mat, so there was no help from the down. The photo here shows my winter tent decorated with light snow on the third morning while I was pulling it down, and the frost-heave in the ground nearby. Yep, that ground was cold! Mind you, I think the snow grass definitely helped me a fair bit as well as it mostly kept me off the soil. (We won't go into the last night of that trip, when we got about 100 mm (8 in) of snow overnight: we left fairly quickly after that!)

MontBell Pillow

When I first saw the extra pillow I was not very impressed with the idea, but two things changed my mind. First, the pillow actually works: my head is stable on it, unlike some 'balloons' which left my head rolling off the side. I am fairly sure the reason for the stability is the two internal baffles you can just see in the second photo: they stop the middle from bulging. The second reason was the really neat way the pillow attaches, or anchors, to the mat. The inset in the photo shows the little toggles they use for this. The toggles are light and very reliable. The light weight of the pillow (68 g /2.4 oz) and the low cost (US$29) help as well. By way of comparison, my MYOG cored-foam pillows weigh 110 g (3.9 oz): somewhat heavier!.

Yes, I did use the pillow on the alpine trip mentioned above. I found that it worked better for me if I stashed some flat gear (day-time clothing) under it to raise it slightly. But this little pillow has become a keeper for us.

MontBell UL 90 and MontBell UL 120 Mats - 5
MontBell extra mat.

MontBell Sit Mat

You have to admire both the ingenuity of the Japanese designers and the alertness of the MontBell PR people. In addition to sending a pillow with the mats they sent the little fold-up mat shown here. It seems to be made of the same fabric but firmer foam, and has the toggles and holes. Oh - the spacing matches the main mat, and the sit-mat does include the same toggles. The sit mat can therefore attach to the foot of the air-mat.

The MontBell sit-mat weighs 71 g (2.5 oz) and costs US$17. Once again, my first reaction was 'ho hum,' but after a little while I found I was taking this fold-up mat everywhere. Not only to tie to the bottom end of the MontBell airmat at night, but also on day walks to serve as a sit-mat for meal stops. Why did it slip so easily into my standard gear? I think because it managed to combine comfort, durability and ease of packing. My other (MYOG) foam sit-mat of the same area - which does not fold up, is always a bit of a pain to get into my pack at the last minute, when everything else has already been packed away, and I find I am still sitting on it. (Happens all the time!) But this one is much easier to pack away. Very ingenious. Another keeper.

This is a mini-review in the 2011 Lightweight Airmats State of the Market Report. The articles in this series are as follows (mini-reviews can be found in Part 2), and a subscription to our site is needed to read them.

  • Part 1 covers the basics, testing methods, and lists all the mats in the survey.
  • Part 2 examines the actual mats, and the performance of each mat tested.

Disclosure: The manufacturers provided these products to the author and/or Backpacking Light at no charge, and they are owned by the author/BPL. The author/Backpacking Light has no obligation to review these products under the terms of this agreement.


"MontBell UL 90 and MontBell UL 120 Mats," by Roger Caffin and Will Rietveld. (ISSN 1537-0364)., 2011-08-23 00:00:00-06.