The defining characteristic of the Assos interActive Spring base layer is the interActive fabric itself. The yarn is made from 3 fibers -- 2 micro hydrophilic fibers are wound with a third real silver fiber. These fibers are different in shape and form, but they're woven in such a way to provide the base layer with what Assos refers to as a "Push and Pull" effect. The pull is the way it actively moves moisture off your skin, and the push is the movement of the moisture through the fabric itself in order to facilitate evaporation.

InterActive has quite a bit more stretch than what you'll find from other base layers, giving it a second-skin feel unlike the rumpled, cottony experience of other brands. Assos keeps the seams to an absolute minimum to reduce chafing, and the cut itself is made in the same AEPD II design Assos uses in their jerseys. When you stand up in the interActive, it pulls upward at your belly button and the shoulders will feel tight. But the idea is this: with the combination of the super-stretch material and the riding-specific cut, it'll "click" into place on your torso when you reach for your bars. Don’t judge it by trying it on in your bedroom -- judge it by how it feels when you ride.

The "Spring" designation of this base layer means two things: It has short sleeves (not sleeveless), and that it's made of a 190g weight interActive fabric, not the lighter material reserved for the "Summer" base layers. Assos suggests use of the Spring base layer between 57 and 72 degrees. In cooler temps you'll be better served with the insulation provided by the Assos Powerstatic base layer. In warmer temps, the Summer interActive is more appropriate. Available in sizes Small-TIR, in two colors -- Black and White.