Surely, the windshirt quest will never stop. Finding an ideal active layer for days which are neither warm nor arctic, neither calm nor storming fiercely, involves delicate balancing of contradictory attributes. The shirt must be significantly wind resistant, but quite breathable. It must be light, but tough, especially given that a windshirt will be used more than just about anything else aside from undies and socks. It must resist rain, and in a durable fashion, not absorb much moisture, and dry quickly when it does.
Conventional windshirts are made from lightish, tightly woven nylon fabrics. The good ones succeed at most of the above, having only suboptimal breathability and durability (though they’re tougher than most think). An example would be the Rab Cirrus, which I discussed here. The recent trend of light softshells, like the Rab Zephyr, typically use a poly/spandex blend. They breath well and the good ones are very tough, but the fabrics tend to suck up and hold on to water in a manner which makes them a liability in multiday wet conditions.
As discussed in the first link, Pertex Equilibrium promises to hit almost all these metrics, save durability. Much though I liked my Rab Alpine jacket, the fragility just wasn’t going to stand. Ergo the continued quest.
The recent BD Alpine Start hoody is the closest thing I’ve yet found to an ideal windshirt. It’s more breathable than a Cirrus, and more wind resistant than a Boreas or Alpine jacket. The Schoeller fabric is 93% nylon, and 7% elastane (spandex, in essence). The weave is exceptionally tight, and the fabric thinner than you’d expect for the weight (80 g/meter), all of which gives me high hopes for durability. The nansphere DWR is (thus far) very good. I’m not calling this a proper review, as these two things aren’t subject to meaningful comment until after months of heavy use. Most importantly, it dries very fast indeed.
Thus far I would change nothing at all about the fabric, and the fit and features are 96% good to go. The hood is big, big enough to go over a smaller helmet, and has an interior channel for a drawcord, with cordlock adjustments on either side of the face. It cinches down tight over a bare head, and moves with you. There’s a single chest pocket which is fabric backed, a slim/athletic fit (medium is in line with a company like Rab or Montane), elastic binding at the wrists, and a full circumference drawcord at the waist. Nothing else is needed in a windshirt. The main zip is a nice metal #5, one of my favorite things. My medium weighs 7.2 ounces after cutting out the tags and trimming the hood drawcords.
The hood is the major thing I would encourage BD to change. The bottom/chin area could go a little higher for max protection, and the whole hood feels set a hair further back and is completely natural. When my pack pulls the shoulder back a hair, the zipper presses on my neck. Not a big deal, and easily dealt with, but less than ideal. The cordlocks and excess cord are hidden inside the hood, and I’d prefer them outside. Exterior cordlocks can be used without unzipping the hood, and exterior anchors for the excess don’t flap around and get caught in the zipper. As seen above, my standard procedure with this sort of think is to tie knots that hold the hood with a little tension (a good default setting for general use) and then trim the cord so that most of the time their is no excess flapping around.
To further the nit-picking, ideally the chest pocket would be backed with mesh rather than fabric, to save a few grams and maximize breathability. I also wouldn’t mind another 1/2″ or length in the sleeves to make a better seal over gloves, though the current arrangement would stay out of your chalk bag nicely. The wrists are flexible enough to roll up over my elbows, and the armpit articulation is fantastic. The hem does not ride while cycling or during the most exaggerated pole plants.
In short, the Alpine Start hoody is close to ideal, an impressive first effort on a demanding garment. Construction is as good as or better than any top brand you might name. As mentioned, arm articulation is massive, and most of the seams are felled and then double-stitched. The only drawback is the price, a rather egregious 149 dollars. It makes more sense to spend big bucks on a windshirt than on a raincoat, as the former will be used more. Nonetheless, I’d have hesitated long and hard at full retail on this one.