Waterproofing
The Toray Dermizax 3D 2.75L laminate Helium UL rain jacket and pants differ from the 2.5L or 3L laminates in several ways. One is what those laminated layers are. The 3L laminate consists of a bonded inner fabric, waterproof membrane, and face fabric layers while the 2.5L laminate loses the inner lining fabric in favor of an inner lining, which saves weight and increases packability. But Helium UL’s 2.75L laminate is anything but – it has a subtly engineered raised dot pattern printed directly onto the waterproof membrane that helps maximize airflow with maximum stiffness on the innermost layer.
And another big way the Toray Dermizax 3D 2.75L differs from other rain gear on the market is that instead of using a thin membrane that allows vapor to escape while keeping water out, it uses a non-porous hydrophilic membrane that absorbs sweat and wicks it to the outside so that during high-output activities there is no nasty clammy feeling.
While these pants are some of the most comfortable pants I’ve tested during high-output activities in cool to warm weather, their lightweight fabric soaks up wind-driven rain after more than three hours. On many levels, this is a good time to stay dry; for others, where the rain is constant and cold, it is not.
Inhalation and exhalation
Helium UL rain pants are a favorite of warm weather rain pants in large part due to their excellent breathability. Although its side zippers are closed at the sole ankle area with non-adjustable elastic ankle cuffs, the fabric itself does a good job of allowing sweat and human vapors to evaporate quickly.
They are not windproof and, although they are more breathable than other rain pants I have tested, they are effective in most conditions. Keep the length and size of the stormy weather you expect in mind when choosing between these pants and the most durable ones.
On a sad and memorable day with temperatures hovering around 40ºF (4ºC), the Helium UL pants were simply not the right choice. The breath that made them feel good on warm days felt bad as the wind seemed to blow between them. After a little more than three hours of steady wind-driven rain and snow, the outside moisture broke through the membrane—unfortunately, more cold hours lay ahead. It’s not the pants’ fault, but a real reminder to keep in mind the circumstances in which they will be worn– these just weren’t the right choice for a day with that kind of forecast.
Comfort and fit
The Outdoor Research Helium UL rain pants are very comfortable, in large part due to the sheer amount of movement they offer the wearer, with a stretchy fabric than most other rain gear on the market. They have a nice next-to-the-skin feel that isn’t too oppressive during the high-production tasks required while wearing them in warm weather—which is when I’m personally more likely to choose them over other rain pants.
I sized up to avoid the overly tight fit of the Helium front row and found that these pants don’t run as small as their previous iteration. This way, I have more than enough room to layer easily if needed—my preference is for rain gear to be on the baggier side although I’m probably fine with a smaller size as well. If you like to have ample room for layering and/or have incredibly large thighs like I do, I would recommend getting sized.
The Helium UL rain pants have a medium rise that helps keep rainwater from seeping into the wearer’s pants—necessary in wet conditions. The waistband is easy to adjust with a drawstring but is comfortable; the grippy stretch that helps keep the pants from riding up or falling down while moving isn’t particularly pleasant on the skin.