Comparison of Montbell Tachyon and Patagonia Houdini Air Windshirts

Thank you so much for the testing and  interesting discussion.

Personally surprised how relatively low the CFM of the new Houdini Air is. Saved me some money too, but still in search for a better alternative. In the mean time I’ll squeeze some more use out of my 2014 Squamish.

I’m surprised the Arc’x Squamish (are there fabric generations at work here?) gets such a high value (42.5 CFM). I have a few of the current versions of the Squamish and do find them to hit a pretty sweet spot between wind resistance and sweat-dissipating comfort. I wouldn’t have guessed they would move almost 3x more air than the Houdini Air though! The fabric feels tougher and less supple than the Houdini Air and I wouldn’t hesitate to do some brush bashing in the Squamish. A little more hesitant to wear the Houdini Air into alders. And no way I’d wear my Tachyon into brush…

I was curious about the Squamish, after having read so many comments about it.  I received a Squamish and a Nodin today and will start looking at them tomorrow. I agree with Phillip’s comment from my initial handling.  The Nodin has a lighter feel.  More like what I would expect from a windshirt.  I received mediums, which is what I generally get for Arcteryx jackets.  I would need a large for these jackets.  They are cut pretty slim.

I’m confused – in 2018 MB changed the Tachyon to 22 CFM, and now they changed it back?
Does anyone have advice which (current version) lightweight windshell to use for what purpose, I lost the overview.

Why do you believe the Tachyon was 22 CFM in 2018? I believe the present  Tachyon that I tested was introduced in 2018.  Do you have a source?

Steve

Hi Steve, sorry it was 20.2, I’m referring to this post:
https://backpackinglight.com/forums/topic/a-new-paradigm-for-analyzing-pwpb-systems-like-the-columbia-outdry-ex-featherwei/#post-3523435

I’m not sure though if parka and jacket are the same item?

That is the same garment I tested.   The test you refer to came up with permeability that is twice the level I measured.  In my review, I discuss the calibration procedure for my test instrument.  I cannot speak to the calibration techniques used for the instrument that produced the other data.  I expect that in normal use, the difference may not be particularly perceptible to the user.  It all depends on conditions and exertion level.  I spend a lot of time at high altitudes.  High winds are often present and the higher CFM of a Houdini Air, compared with a standard Houdini will permit too much cold air infiltration.  On the other hand, at hiking speeds, if you look at the speed vs permeability graph in my report, there is so little CFM penetration that the impact on cooling is minimal.  I never use my Houdini Air anymore.  After using it for a while I went back to the standard Houdini. When I need protection from the wind, I want a virtually windproof fabric.  If I don’t need protection from the wind or a little extra warmth, I simply remove the windshirt.  At this point,  I am now using a Montbell Versalite.  I will be publishing a review of this jacket shortly.

When I need protection from the wind, I want a virtually windproof fabric. If I don’t need protection from the wind or a little extra warmth, I simply remove the windshirt.
Far simpler.

Cheers

Maybe Richard Nisley can comment – as he did the linked test with different results.

Stephen, I also thought about the Versalite. How are you using it? As a rain jacket as well?
I think regarding ventilation in both a wind and rain jacket, pit zips are far superior.

Using it as a windshirt and a rain coat.  I hope to complete my write up this week.

Steve

Stephen,

Looking forward to your analysis of the Versalite; very curious to see how it compares to conventional woven windshirt fabrics.

Have you looked into the new, more durable Gore Shakedry fabric? Montbell is using it in their Peak Shell and list its MVTR as twice that of the Versalite. Are we getting close to being able to carry one shell for both wind and rain protection?

It is quite common to use a windshirt as a bug shirt. In that case, the idea of simply taking it off, or adding pit zips misses the point. You want full coverage, but with as much breathability as possible. Wind resistance becomes a secondary concern, especially since most backpackers also carry a rain jacket (which offers a lot of wind resistance). The idea of a very lightweight, very breathable bug shirt (that happens to be called a wind shirt) is appealing to many.

HI Stumphges:

I looked at one while in the Montbell store.  Seems pretty fragile.  I don’t think Montbell’s offering is the newer fabric and construction version.  Their website recommends utilization that does not place any stress on the membrane.  However, I would not be too persuaded by any of the published breathability numbers without knowing which test was done and what coatings are bonded onto the membrane.  Is there any information on the actual construction of the shake dry membrane?  I am guessing if it is coated with a hydrophilic membrane to make it oleophobic, then it would have higher breathability on the sweating hot plate or the JSA L1099 B1 test.  Too expensive for me!

Hi Ross:

If someone thinks they have a windshirt breathable enough to wear in mosquito territory, I would love to measure its performance.  Seems to me if it is warm enough for mosquitoes to breed, it is probably too warm for a windshirt.  Mosquitoes thrive in hot humid environments.  In such a place there won’t be enough vapor pressure differential to expel moisture that you produce.  If anything, moisture might flow in the wrong direction.

Steve

Steve,

I think the Montbell Peak is the newer, more robust Shakedry, just based on Montbell saying it’s OK for backpacks and the release year. The earlier version of Shakedry were not recommended for backpacks. Regarding oleophobic/hydrophilic membrane, Montbell recommends frequent washing to avoid oils foiling the membrane, so it would seem not. Regarding fragility, you have handled one and I have not:)

Steve, Ross, I wore an alpine start on a pretty easy hike today in high humidity, light rain and 70F temps. Much more water soaked my shirt from perspiration than from precipitation. If the bugs had been out I would have been troubled, as they’d have got through my open front zipper. That said, I frequently use my Alpine Start for bug (and sun) protection in the 50s and 60s to good effect.

@Stephen — Mosquitoes are quite common in the Pacific Northwest (and similar places). They can be found in abundance on days when the weather is dry (as is common in the Pacific Northwest in the summer). It is rare for temperatures to get anywhere near body temperatures (typical temperatures are around 65 degrees F). But I have seen them in large numbers while sitting around camp, even as the temperature got down to the 50s. (The state of the flowers has more to do with mosquito numbers than anything else).

In general though, a bug shirt is not needed for warmth. If you are walking around on a sunny day (with no shade) you really don’t want to put on an extra layer (although it helps with sun protection as well). The more breathable the fabric, the better. The Original Bug Shirt (https://www.bugshirt.com/) is excellent, but heavy. I’ve used rain jackets as well as some wind shirts for bug protection, but the challenge is finding a wind shirt that is as breathable as the Original Bug Shirt. It may not be possible — I’m not trying to find a miracle here — but a good compromise between weight and breathability would be nice.

By the way, this is common with gear. The lightest sleeping pad for the weight is closed-cell foam. But it isn’t that comfortable (and they are bulky). There are very lightweight inflatable mattresses (with no insulation) that offer good comfort, but no insulation. It is the compromise between the extremes — fairly lightweight, comfortable, but well insulated — that got the masses to buy into the NeoAir (and similar) pads.

I wore an alpine start on a pretty easy hike today in high humidity, light rain and 70F temps. Much more water soaked my shirt from perspiration than from precipitation. If the bugs had been out I would have been troubled, as they’d have got through my open front zipper.

Why not just get wet?
We wear loose Taslan shirts, maybe better described as smocks, when walking. Because they are loose, they don’t get too hot. They provide some protection against the scrub and insects, and a lot of protection against the sun. If it rains but is a bit warm (70 F is ‘a bit warm’), we just get wet – and walk faster. Being wet will NOT kill you.

Jan & Feb are peak fly times in our Alps. And they really are there in huge numbers. Our solution is simple: we don’t go there then.

Cheers

I am clearly at a disadvantage.  Here in Colorado, we don’t seem to have humidity or mosquitoes.    You have my sympathies.  I was buzzed by two flies on my hike today. First flies of the season.

Which of these options (I have the original, 2010 Houdini, not sure how it compares) would you recommend for our purpose (as a wind shirt, leaving aside the quite interesting report of the Versalite)?

As I mentioned in the the Versalite article, that is the garment I am presently using  as a windshirt.  Of the other windshirts I have tested and/or used, I would go with the latest Houdini.  I am expecting to receive several windshirts shortly, so you may want to wait a couple of weeks to see the results of those tests.

Thanks Stephen!