Blending safety with value

Safety and functionality are among the top priorities for mountain bike gear and apparel brands. Fox Racing has focused on these priorities for over four decades, offering apparel and protection for action sports athletes and enthusiasts. Fox’s all-new half-shell helmet, called the Mainframe, was adapted from other helmets in Fox Racing’s lineup. This helmet design is aimed at the trail rider looking to save a buck and still get cutting-edge safety.

Tech features: The Mainframe has a few standout safety features right out of the box. It was awarded Virginia Tech’s best safety rating of five stars. It also passes the standard CPSC ratings for a bicycling helmet, has extended coverage construction and a MIPS impact protection system. With no downsides and plenty of benefits, it’s almost a no-brainer to use MIPS protection systems in modern helmets. What the simple MIPS integration does is reduce the rotational forces in a crash by soaking up and redirecting forces that might otherwise be transmitted to the brain. 

Taking features from Fox’s lightweight full-face models, the Mainframe uses a venting system with channeled in-mold EPS for airflow. There is also a washable, moisture-wicking liner to keep things cool on hot rides. Overall, the helmet is straightforward with minimal but important features. The simplicity keeps things relatively light across the three adult sizes (small, medium and large) and the dedicated youth size. Yes, that’s right, you and your little rider can rep identical helmets with all of the same uncomplicated features.

Field test results: There were varying responses from our test riders when they caught their first glimpse of the Mainframe. Some were not attracted to the styling or look of the Mainframe, while others thought it was a nicely designed, smooth-edged helmet. 

After riding with the helmet, testers reported that for a well-rounded all-mountain and trail-riding helmet, it was comfortable and had sufficient airflow for hot summer rides. We recommend a warm cap under the helmet when things get below 40 degrees Fahrenheit, but that’s just because of the great airflow. The padding at the front of the helmet is snug, but we would have preferred some additional pads towards the back of the retention system and an adjustable dial to provide more comfort. Although we did not have a single rider complain that this helmet was uncomfortable, extra padding widths or options would help further fine-tune the fit of the Mainframe.

 A miss for some was the fixed visor. Some riders reported that they couldn’t help noticing it in their peripheral vision, and they were bummed that there was limited space to re-position it up higher to store goggles or mount camera/lighting accessories to this area. The trade-off is that the visor will break away in a crash and helps save weight by not requiring the extra hardware needed for it to swivel and adjust. Overall, Fox Racing nailed a great entry-level trail helmet with tech and features trickled down from higher-end models to create the value-driven Mainframe. It’ll keep you cool and comfortable on a hot trail ride and keep you protected with MIPS, plus your wallet will thank you.


• Great airflow and ventilation

• Modern safety at a great value

• Extended coverage towards the back of the head


• Non-adjustable visor

• No pad-size options

Star Rating

4.5 out of 5

Price: $90

Weight: 360g (medium tested)

Colors: Fluorescent yellow, black/gold, fluorescent red, slate blue, white