CFD and significant testing create the fastest road racing suit, optimized for high speeds when the race splits apart.

Product features

• Made to be the fastest option for high-speed road racing
• Dimpled shoulder and sleeve fabric for boundary-layer aerodynamics
• Smooth body for reduced skin friction and laminar flow
• Premio-based short portion for aero comfort
• Progetto X2 Air seamless seat pad for all-day comfort
• 2-way YKK® zipper
• Lasered tone-on-tone logos at back of leg and stitched scorpion patch at top of back

• Weight: 242gm
• Temperature 14°C - 32°C / 57°F - 90°F
• Fit: Aero

PUSHING THE LIMITS OF SPEED Military test pilots in the 1960s coined a phrase for pushing the aircraft to its limits, going all in, and risking their lives at the edge. The throttle levers with the knobs or balls at the top were pushed all the way forward against the cockpit wall: Balls to the Wall. BTW is for those days, those races where you never drop out of your 53x11 or 12, when you're sometimes in the gutter or cornering at the limit of adhesion. When you're all in, taking risks. Like the planes that inspired the phrase, the BTW Speed Suit uses cutting-edge research and construction in the pursuit of speed: CFD analysis, 3D test mannequins, fabric research and testing, numerous wind tunnel tests, and then testing in the WorldTour. At the beginning of the research project, we were set to sacrifice comfort in the name of speed, but in the end we kept fully breathable, fully stretchy fabrics. There’s a little more Lycra®, so you won’t stay quite as dry, and the shoulder fabric is slightly heavier. And it doesn’t have the Sanremo front opening, so your pee stops will be a bit more challenging. All that is a small price to pay for an incredible THREE PERCENT total aero drag savings compared to the fastest-in-class Sanremo Speed Suit. That 3 percent is at higher speeds, especially in the 45-65 kph range, when it really counts. You can get the BTW suit in your team graphics through Castelli's custom program, or this stealthy ninja black version to tear up your local Strava segments or group rides.