Most TT's and triathlons take place anywhere from late spring through early fall, often on some of the hottest days of the year. A TT/tri-specific lid can certainly speed up your ride, but not if it isn't built with enough ventilation to keep you cool. How to make "aero" helmets that save watts without leaving cyclists trapped inside a stifling bubble is a recurring challenge for helmet manufacturers. That's why we're impressed with the Giro Aerohead MIPS Helmet's wind-cheating profile and efficient venting system, which incorporates more cooling channels than the Aerohead Ultimate and features the added protection of Multi-directional Impact Protection System (MIPS).

On the outside, the Aerohead uses a pretty standard In-Mold construction; polycarbonate fused to EPS foam acts as an initial shock absorbing layer and keeps the helmet's efficient profile intact. Inside, a MIPS liner feels barely perceptible as you ride, but significantly reduces the likelihood of brain injury in the event of a crash. It's a technology that's becoming ubiquitous in helmets across disciplines because it rotates slightly upon impact to quell the damaging sloshing energy generated by certain impacts.

After addressing safety, Giro devoted significant energy to developing its Wind Tunnel ventilation, aptly named for its ability to usher air internally through the helmet without impacting aerodynamic efficiency. You can ride tucked on your aerobars on a sweltering tri course and the helmet will deliver a breeze to cool your head while helping you slice through the wind faster than your competitors wearing regular road helmets.

Other touches like a wrap-around ZEISS visor serve to make T1 faster and limit on-the-bike distractions, with the magnetic anchor giving you the freedom to flip the visor up quickly when you don't need it. Giro's Roc Loc Air fit system makes an appearance in the Aerohead as well, delivering simple, efficient adjustability to ensure the helmet stays in place throughout your ride.