Eurobike: Innovative Tri Kits From Castelli

  • By Aaron Hersh
  • Published Aug 30, 2013
  • Updated Jul 29, 2015 at 5:01 PM UTC
The T1 Stealth Top, $149, is a full-sleeve top designed explicitly to reduce aero drag on the bike and to be removed for the run.

Castelli, an outstanding, innovative cycling gear company, dipped their toes into triathlon this year with a pair of well fitting if not totally unique tri kits. Now with a little experience in multisport, the company is diving full force into triathlon with a broad offering of tri apparel boasting a bevy of novel features aimed for long-course racers.

T1 Stealth Top

Castelli is attempting to create an entirely new category of tri gear. Several apparel makers are trying to maximize the aerodynamic properties of tri kits, but Castelli is the first to create an entirely separate piece specifically to reduce wind drag. The T1 Stealth Top is a long sleeve shirt designed to be worn over a tri kit to reduce aerodynamic drag and provide sun protection. Like a swim skin, it’s a one-discipline piece of gear. Castelli suggests ditching the top before the run. Former pro cyclist turned engineer Robby Ketchell helped Castelli craft this top as a single-discipline time saver. His aero testing found that it saves 3:01 for a rider averaging 23mph over an Ironman by improving airflow over the rider’s upper body. Time trialists cover their forearms because some fabrics can reduce the pressure drag created by air passing over the rider compared to bare skin. The T1 Stealth Top replicates that benefit. Strategically placed textured fabric over the shoulders, upper arms and back helps reduce pressure drag, according to Castelli. Sun protection is another benefit. The top covers the arms, shoulders and upper back, three spots that tend to burn during longer races. The top can be worn under a wetsuit or donned in T1. Stripping it off in T2 should be short and easy. The top will cost $149.

RELATED: Castelli’s Tri Kit

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FILED UNDER: Gear & Tech / Hi Tech Upgrades TAGS: / / /

Aaron Hersh

Aaron Hersh

Aaron Hersh is the Senior Tech Editor of Triathlete magazine. To submit a question, write Aaron at

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