Just In - X-Bionic Winter Trekking Top

New for review is the latest top from Swiss baselayer specialists X-Bionic, a zoned Winter/Treking and Ski Touring mid-compression top.


XBionic, same people as XSocks, is the most zoned, zoned baselayer clothing out there and, in very simple terms, uses different densities and configurations of padding and fabric to suit different areas of the body based on a lot of serious lab research.

So, the shoulders on the winter top have a thick padding both to add insulation and to increase comfort when worn with a pack, then the centre and small of the back have obviously channeled areas that X-Bionic says are designed to both insulate and draw sweat away from the skin, other areas are thinner to conduct warmth away without impeding performance. There are even 'Underarm Sweat Traps' no less.


At first glance the zones are really obvious though, as with most X-Bionic stuff, it looks like it's been shrunk in the wash until you put it on when you get a proper, next to skin fit for maximum efficiency. The result, says X-Bionic, is a system that cools you when you're sweating, keeps you warm when you're cold, but is also carefully designed to reduce sweat rather than preventing it.

The thinking behind this last bit is that a thin film of wetness is left on the skin, which in turn while not feeling wet, evaporates helping cooling when needed, but still prevents you over-cooling during recovery.


If all that seems hard to grasp, don't worry. This is the most complicated baselayer technology in the world. So complicated that the excessive box-based packaging folds out into a massive library of graphics and information. It's all a bit much and hard on trees too.

The bottom line is 'does it work?' and we'll be letting you know. It's easy to be cynical, but we've found the X-Bionic boxer shorts to be excellent, so we're keeping an open mind.

You can find more X-Bionic information, lots of it, at, hmmm, all that packaging and we can't find the URL, hang on... www.x-bionic.com