Some companies think that a sleeveless jersey is really just a tank top with pockets. These companies take a running singlet, stitch on pockets in the back and some elastic at the hem. In a flash, they've turned a running top into a riding top. Assos begs to differ. Crossover gear is fine, so long as it fits the purpose of riding. A converted running top doesn't.

The Assos ns.13 Lady Sleeveless Jersey is constructed as a jersey, one that despite the apparent simplicity, is incredibly complex. The result, however, is simple. It is a second skin, an enhanced skin that feels like wearing almost nothing at all.

The front of the ns.13 Lady jersey has the heaviest, stretchiest fabric of the entire piece. The wicking spandex is designed to hug the body, and with six panels (yes -- six in front!) the material hugs the body well. The collar is non-existent, thanks to a realization that this is a top for the warmest days of summer. The full-zipper is an acknowledgement of the same fact. It is for the warmest days of summer. Unzip going uphill, zip going downhill.

The front panels are comfortable, practical, aerodynamic, and make the wearer look good. But it is the back panels that really make this top a stand-out. The essential panel is the "rear panel stabilizer," a patented Assos feature. Assos calls this mono-stretch, which means it only stretches side to side. This helps keep the jersey snug to the body as well as prevents loaded pockets from bouncing up and down your back.

Above the stabilizer and below the pockets is a new, low-volume honeycomb-like fabric. The three-dimensional shape of the material works moisture away from the body and helps it evaporate quickly, keeping your back dry and comfortable, even on the hottest of days. One other detail that delivers superb fit: At the bottom hem, there is elastic at the back, and no elastic at the front. The prevents bunching and tension on your tummy.

Assos is always working something interesting with the pockets. The ns.13 has a four-pocket back. There are two deep pockets on either side of the back. Running down the middle are two smaller pockets, each protected by its own flap of fabric. The upper pocket is great for a cellphone and other sizable stashables. The lower is great for a credit card and/or key.

One note to keep in mind: Assos designs all of their clothing with their AEPD (Assos Ergonomic Pattern Design) philosophy. When you put this jersey on, it might pull upward and seem short at your tummy when you're standing straight up looking in the mirror. But it's not designed to be perfect when you're standing in your bedroom -- rather, they're designed to "click" into place when you're on your bike. When you're on the saddle reaching for the handlebars, that's when you'll experience the beauty of Assos fit.

The Assos ns.13 Lady Sleeveless Jersey comes in Black, Blue, White, and Yellow. In all cases, the back remains White, better for keeping cool in the heat.