I have 2 bits of kit on the go from Rab, the Alpine Jacket, an unlined windshirt and the Strata Jacket, which is their new Polartec alpha insulation piece.
The Alpine Jacket is actually a hoody, made from Pertex Equilibrium. I am completely sold on this fabric, it’s heavier in weight than Pertex Classic or other nylons but this is more than compensated for by its moisture movement properties. Many Pertex and nylon windshirts are clammy and stick to you when your sweating but not Equilibrium. The Alpine Jacket is, as the name suggests, a mountain piece but it’s also great for biking and winter running. Semi wired adjustable hood with the all important full halo head gripper cord to keep it on into wind. 2 pack friendly pockets that double as vents. Generous elasticated cuffs and elastic draw cord hem with toggles on both sides. The Alpine Jacket has all you need as a light mountain jacket with nothing you don’t except maybe the hood (more below). The only change I would make to the current design is to make the hood retaining strap wider and the hood adjustment elastics need to be controlled somehow. I might tighten the fit up a touch as well but I am a thin-ish medium so maybe that’s just me.
My only wish is that Rab would rename this garment the Alpine Hoody and make an Alpine Jacket! I find the hood unnecessary. When climbing I have hats or hoods on shells to use. When biking I can’t use it and when running it adds too much weight to the collar and gets dragged round in the wind. As I said above my only gripes with the jacket are with the hood detail so getting rid of it fixes all that!
Even with the hood I really rate this jacket. My basic clothing system consists of a base layer and then 2 Rab Windshirts, one lined (VR Lite Jacket) and one not (Alpine Jacket). I find this combination with a shell can be used all year round for all activities, with an insulated jacket added for winter climbing. I wore my alpine jacket for more than half of the Relentless 24 hour mountain bike, only switching to a shell when it was raining persistently overnight. The DWR on the Alpine Jacket is very good and it lasts surprisingly well in consistent light rain but because it dries so quickly it can also cope with short bursts of heavy rain.
My other new jacket is the Strata Jacket. The Strata jacket is a lightly insulated jacket using a new synthetic fibre from Polartec called Alpha. The main feature of Alpha insulation is increased breathability over Primaloft Sport or Primaloft One. Alpha is designed to be used in garments where the wearer is likely to be generating some body heat and along with it, some perspiration. So Alpha is found in the lighter selection of synthetic jackets that may be worn for winter climbing or slipped one and off between bouts of work at the crag but definitely lighter than a belay jacket and with a more air permeable outer. The Polartec Alpha site is a little short on details but the jist seems to be that because Alpha is knitted into a sheet, it can be used in jackets with more breathable outer face fabrics that would not be able to be used with the older loose fibre type insulation. The gaps in the knitted sheet are larger and more regular that the older fibre and allow better movement of air and moisture.
Although the Polartec info is very vague, I have to say that what they say about Alpha is true. My Strata Jacket is noticeably less clammy that other fibre fills, it has a reduced warmth to weight ratio but not by that much. If you have to work hard with the Strata on then you do not feel as uncomfortable and prickly inside it as you would think and as you cool back down you are still pretty dry on the inside. So it does behave pretty much as advertised. Another bonus of the fact that the fibre is knitted into a more stable sheet is that there is no longer any need to stitch baffles into the jacket to hold the insulation in place and now you can have a more normal looking jacket which can double as an everyday piece.