The Fathom mountain bike helmet from Giro has been referred to as the Atmos of the Dirt, and for good reason. Though the helmet is not a simply a visor-ed version of the road mainstay, the styling, ventilation, and technology are virtually the same. Cross country riders will appreciate the large open-vented shell structure and aggressive styling. Giro has made the Fathom lighter and stronger lighter without compromising safety or driving the price through the roof. The same In-Mold shell construction process is used, and the Roll Cage internal matrix spans the design, but a new Thermoformed SL material replaces the original version, dropping grams and exceeding the original’s strength.

The shell of the Fathom may look like the Atmos, but it has fewer vents, for more continuous structure in key locations for greater impact protection. 23 Wind Tunnel™ vents allow massive airflow to keep the skull cool and create the signature look. The In-Mold construction features the EPS liner that absorbs shock and dissipates the energy through the helmet structure and away from the skull. For retention and fit, the redoubtable Roc-Loc® 5 handles the job with its micro-adjusting dial. The whole fit assembly can be vertically adjusted 15mm via a shell mounted tab. This allows the rider to accommodate the depth and shape of the skull for an optimum fit and proper angle. The visor is easily removable. If you require a lightweight helmet with maximum ventilation and XC level protection, the Fathom should be your choice.