Rab Cirrus Wind top black L & M for $65 @ Backcountry Outlet

Many people like this jacket, but if you are looking for something highly breathable, it's probably not the best choice (being made of Pertex Quantum).

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=77522

Discussion of CFM on Rab Cirrus. People were comparing these to pre-2013 houdini models which are consistently considered the ideal in terms of windshirt breathability. Too bad they aren't offering them in small or I would consider picking one up at this price, good find.

Jeremy, could you let us know your height, waist and chest dimensions? I'm curious to know which size might fit me. thx.

I tried this windshell & though I liked the fit, it didn't breathe very well. Nice shell anyway.

> Rab Cirrus. People were comparing these to pre-2013 houdini models which
> are consistently considered the ideal in terms of windshirt breathability.

How is that possible when the Rab Cirrus is made of Pertex Quantum, and Pertex Quantum is listed as Air permeability 1.0cc maximum? 1.0cc is approximately 2 CFM, right?

I don't have a measuring tape with me at the moment, but I *think* my chest is 44", 5'10", 36 waist, 190 lbs. I'll update tomorrow when I get home.

Thanks Jeremy. That's enough info for me. I appreciate the reply.

Does anyone out there have a Rab Cirrus that they could do the breath test on? I'm really perplexed because the fabric specs indicate it should be low breathability.

> Does anyone out there have a Rab Cirrus that they could do the breath test on? I'm really perplexed because the fabric specs indicate it should be low breathability.

Don't be perplexed, you are correct, according to the thread posted above. The Cirrus is reported as having low breathability. If you read the infamous thread 77522 (one of the most frequently referenced threads on BPL?), you'll notice that the Cirrus is compared to the old Houdini for ONLY a few posts early in the thread, before Peter Fokkinga and Richard Nisley spot an error on a Chinese website and Nisley revises the CFM estimate down from 10cc to 1cc.

The breath test you seek is also on the same page of that same thread. See Brian Lindahl's breath tests of about 15 windshirts:

"From a simple breath test, I could quite easily tell the difference in breathability between the old Houdini and several garments made from Pertex Quantum. Pertex Quantum was VERY noticably less breathable (though still slightly breathable – 1cc sounds about right). This was also true for other Pertex fabrics, such as Microlight."

Interesting how persistent an erroneous digit of information can be!

Pertex has the permeability rating for Quantum right on their website and it is 1cc. That might be flaky too! That is why folk like Richard Nisley have careers :)

Bad data is not uncommon. I see errors in website descriptions all the time– stuff like pockets or other features that don't exist, or feature attributes written up by someone who evidently has never been farther outdoors than the mall parking lot.

Don't get me started on weights! The North Face Verto pack weight was off by 25% and we tracked down a North Face polyfil jacket that was off by about the same percentage. I went to the store with a scale and the manager looked it up in the TNF resource manual, which was dead wrong. I have seen data cut and pasted from one Internet venue to another, making the error almost truth. Stuff happens.

"To err is human, it takes a computer to really screw up!"

— Benjamin Franklin

Agree with everything you say, Dale, until that final quote…I'm pretty sure the source for your quote is Aristotle.

You are right Delmar. Sorry about that Paul, I guess I never finished reading that thread. I think I was confusing people's positive experiences (I have read that people like the jacket in general) with the CFM thread you referenced. I stand corrected.

I don't know what to think. My mind just can't reconcile DaveC's statement on that thread that "the 2012 Rab Cirrus breaths just about the same as the 2012 Houdini" with the fact that the that the Cirrus is constructed of Pertex Quantum.

This is the internet, Paul; you're unlikely to find unambiguous data here. Best you can hope for is averages of opinions and the occasional real datapoint or two. Even in science, we don't go to the bank on a single study, much less a single data point, much less a single anecdote. (That's the media's job.) You could have a Cirrus tested, I'd bet you'll find it around 1 CC as is widely reported. Maybe Dave's example was specially aerated with shotgun pellet holes. Maybe his comparison Houdini came from the Fall of 2012, after the new less permeable fabric was in use. Who knows.