1.8 ounces! (medium Hyper D pullover). 3.3 ounces. (Hyper D full zip, hood, cinches, medium). This jacket is available as a super simple and super ultralight pullover or as a full zip. It’s constructed from 1.0 oz Hyper D (uncalendared), which is a 20d fabric that has more breathability than the Argon Wind Shell options. It can also be built from 1.8oz Airwave, which performs very similar to Hyper D in terms of breathability, but has a bit more durability. The hood on zippered jackets has a face shock cord and a rear cinch so the hood can be loose fitting or snug. The cuffs have elastic openings. The pullover version gets an ultralight crossover hood and simple roll hem cuffs.
The functionality of an ultra light wind shell should not be understated. I have replaced many of my light/mid weight insulation layers with wind shell layers due to the shocking amount of warmth provided at such a low weight. Not only does it block wind and prevent evaporative and convective cooling, but it holds a pocket of warm air around your body that provides decent insulation. The Argon 90 wind shell layers provide a good balance of breathability to windproofness (40cfm) that is suited to lower levels of activity with great wind protection. HyperD / Airwave is a large jump up in breathability that is much better suited to higher levels of activity while still maintaining good protection from wind. At 20mph you will start to feel some wind cutting through a bit, but it still stops a lot of it. While I don’t know the actual cfm rating of this fabric I would estimate it somewhere around double that of Argon 90 and it is much more comfortable when putting out a higher effort. It also has a very soft feel that is nice against the skin. These can double as cozy sleep layers.
While it has a DWR coating, I wouldn’t expect much moisture resistance. Since it is not calendared, it can develop “runs”, which are purely aesthetic. Omitting the calendaring process is what allows Hyper D to have such high breathability, but it means that individual fibers can get pulled and slightly misaligned with the fibers next to it. This shows as “pulls” across the weave. Usually they can be pulled back out and over time as more of them occur, they show up less. As mentioned, they are purely aesthetic and don’t affect the performance in any way. Airwave provides the same high breathability but has much better durability than Hyper D.
Daniel –
My experience with this jacket was awesome. I got it in the mail just in time to take on the windy White Mountains during an AT section hike. It was a great cap over my down vest for static insulation at night, at it was also great on its own for keeping warm while hiking in cold conditions. For the latter scenario, I loved wearing it backwards over my pack’s shoulder straps by buttoning the collar behind my neck and partially zipping it up behind my lower back. In fact, I believe the ability to wear it this way justifies the weight penalty of the zipper. I had it on like this underneath a poncho while descending a partially exposed mountainside in really tempestuous, cold rain, and I felt pretty invincible. Afterwards, the Hyper D dried out super quickly due to the nature of the fabric.
Overall, I found that the higher permeability rating of hyper D relative to Argon is a great quality when intentionally integrated into one’s layering system. For me, Hyper D is hyper complementary between a super warm/breathable layer like down, alpha or climashield and an impermeable layer like silnylon or DCF. The only thing is that you really need to protect this fabric from catchy stuff like brambles or velcro hooks.