With all the buzz in the outdoor blog community surrounding The Gore Tex Bloggers Summit, I thought it was about time that Outside San Diego really got to the bottom of the debate.  Does the fabric your shell is make from really make a difference in performance?  This debate has been raging for a long time, and has been the topic in many of my backpacking cooking groups.  To test this theory  I have arranged to use two different shells over the winter season, and review their performance.

As scientific as I would like to be about this test,  I do not have the equipment, the training, or experience to come up with a definitive unbiased answer to the question.  What I can do is convey my experience with the shells as I use them in the field.  I know when I am dry after exerting myself in the rain or snow,  I also can tell when the shell is not working and I experience moisture from the jacket not breathing as quickly as I am producing moisture.  There are many factors at work when using a shell to keep oneself warm and dry,  and these all play a significant role in the performance.  The first is the weather.  Different weather conditions affect the breathability of a garment,  and I cannot control these conditions.  I can note in what type of conditions I have used the shell and you can draw your own conclusions.  The design and mechanical methods of ventilation also play a factor in performance.  As you will read in a minute,  the two shells I have chosen have very different approaches to ventilation.

In a nutshell, an effective shell just needs to work, keeping the wearer dry while working hard in inclement weather, and this is what will decide whether the specific jackets that are being tested work.  The debate aside,  despite the fabric comprising the shell, if it does not work it is not an effective piece of gear.  So really this test is about two pieces of gear and how well they perform.  Here are the two shells that are being tested:

Rab Momentum Jacket:

The Rab Momentum Jacket is a stripped down shell composed of eVent fabric.  This superlight shell has the bare essentials,  leaving everything else off to shave weight.  Weighing in at an average of 12 oz. the Momentum Shell is the lighter of the two jackets, and relies entirely on the breathabilitly of the eVent fabric to keep the wearer dry during exertion in poor weather.

Here is what Rab has to say about the Momentum shell:

Maximum protection at minimum weight. Stripped back of non-essential features but retaining dynamic cut and full technical hood, constructed from highly breathable and fully waterproof eVent® fabric. Ideal for fast and light alpine use, through to adventure racing.

Outdoor Research Foray Jacket:

The Outdoor Research Foray Jacket is a more fully featured Jacket weighing in a little heavier at 15.7 oz., but adding a slew of features for the increase in weight.  This shell is made from 40D GORE-TEX® Paclite® fabric, and has pit zips, and mesh lined pockets to aid in ventilation.

Here is what Outdoor Research has to say about the Foray Jacket:

This lightweight shell with all-season features provides solid protection when a hard downpour sets in for the long haul. Waterproof and extremely breathable GORE-TEX® Paclite® fabric takes the wear-and-tear of the trail while TorsoFlo™ side zippers allow poncho-style ventilation when body heat needs to escape. With no bells or whistles left out, this jacket works as hard as you do but packs down tight once the weather breaks.

Check back often to see how these shells do,  and perhaps answer the question; Does the fabric make the difference?