Castelli Women's PR Speed Tri Suit

It was born from our aero research project at the Norwegian Technical University at Trondheim. Besides having a couple of brilliant professors and PhD students to come up with ideas and do the basic research, they have a couple of wind tunnels, rapid prototyping capabilities, CFD analysis and a true desire to make fast stuff.

Due to the silicone ribs in the arms, this suit would be illegal in cycling but it's super fast for tri. The main body fabric is an impossibly light 50 denier - usually in sports clothing 40 denier is considered ultrafine. The legs and sleeves are long for aerodynamics, while the light fabrics are great for dealing with heat since they're thin enough to not get weighed down, yet the 8% Lycra® content holds a bit of moisture next to your skin for rapid cooling. The insane stretch fits like a second skin on the bike but that doesn't restrict in any way on the swim or run.

This suit delivers real time savings on the bike leg while providing cooling and comfort on the run, but it was made with the expectation of being worn under a swimskin or wetsuit for the swim. It's optimised for high speeds — top age groupers or pro athletes, or anyone looking to set a new PR.