Product News: It's been five years since Fox shook up the enduro market with the first 38 fork. Since its launch in 2020, the suspension fork with its namesake, robust 38-millimeter stanchions has become indispensable in the world of hard racing. This is evidenced, not least, by Richie Rude and Ellie Hoskin's recent EDR World Championship titles in 2025. But as we all know, the mountain bike industry is a fast-moving world. To defend its leading position, Fox has given the 38 a major update for the upcoming model year (MY27). We took a detailed look to see if the Americans' strategy pays off and what technological refinements lie beneath the surface.
The new chassis: Stiffer isn't always better.
Normally, announcements of new suspension forks are full of promises of even greater stiffness. However, in the case of the new Fox 38, we need to say a few more words, because the developers have taken a refreshingly nuanced approach. The distinctive fork crown has been completely redesigned using modern, generative design tools. The software optimizes material placement precisely according to the stresses encountered. The result: The starting weight remains pleasantly constant at 2.200 grams, but the stiffness values have been deliberately manipulated in various directions.
While the fork's longitudinal stiffness has increased by a remarkable 8,8 percent – ensuring maximum braking precision and stability on steep terrain – Fox has reduced its torsional stiffness by 6,8 percent. A mistake? Not at all. An overly stiff fork can quickly lead to significant fatigue in the hands and forearms on rough enduro trails. Thanks to its precisely calculated torsional flex, the new Fox 38 is designed to follow the trail much more smoothly, absorb impacts more effectively, and provide the rider with a more forgiving feel on long, aggressive descents. We think this approach – seeking the ideal compromise rather than pure rigidity – is absolutely brilliant.
Glidecore air spring: Farewell to the tube-in-tube design
A unique feature of the Fox 38 was previously its "tube-within-a-tube" air spring system. That's now a thing of the past. Inside, the patent-pending "Glidecore" air spring now operates, designed to adapt both vertically and horizontally. The idea behind it is easy to understand for any trail rider: when the fork flexes under strong lateral stress (such as in hard berms or on angled root sections), rigid internals can cause friction against the stanchions. Glidecore is designed to accommodate the chassis's flex, thus preventing system-related friction. This promises consistently sensitive and uniform travel, as the forces are transferred directly and unimpeded to the damper.
Towards the end of the travel – a generous 160, 170, or 180 millimeters are available – a new MCU bottom-out bumper protects against harsh metal-to-metal impacts. This elastomer buffer gives the fork controlled progression at maximum compression. Even the biggest impacts in the bike park or on the race track should be absorbed with ease.
Grip X2 Damping: Fine-tuning for setup nerds
On the damping side, the Grip X2 cartridge handles the suspension travel control, which Fox claims remains the pinnacle of gravity suspension (the fork is also available with the Grip X damper). While the basic design remains familiar, Fox has modernized key details. The centerpiece of the update is a completely new mid-valve piston system along with a revised valve stack.
The shape of the valves and piston openings was modified to further refine the oil flow characteristics. Combined with improvements to the familiar VVC system, this is intended to give the fork even more support in the mid-stroke without feeling harsh on rapid, successive impacts. For suspension enthusiasts, nothing is left to be desired: high-speed and low-speed compression, as well as high- and low-speed rebound, can be adjusted completely independently.
Less friction due to increased bushing overlap
In addition to the air spring and damping, the design of the lower legs incorporates further features to enhance responsiveness. Fox has increased the overlap of the bushings by a full 20 millimeters – from 120 to 140 millimeters. This greater overlap drastically reduces leverage forces inside the fork. The result is a noticeably reduced friction and improved longitudinal stability under load.
The redesign of the so-called bypass channels follows the same principle. These have been rotated 90 degrees to optimize the contact pressure between the stanchions and the bushings, which should also reduce wear in the long term. The result of this series of small improvements should be even more sensitive response at high speeds.
Practical: Nice features for mechanics
Thumbs up: Fox has also considered mechanics and hobbyists with the new 38. A notable feature is the new air chamber cap, which now has a 32mm tool slot and can be operated with a standard cassette removal tool. This eliminates the need for bulky sockets and significantly speeds up the process of changing volume spacers. A boon for every mechanic!
Furthermore, the familiar bleed valves on the rear of the casting have been redesigned to be flatter. This ensures a cleaner look and minimizes the risk of damage from stone chips. Speaking of protection: The fork uses the same mudguard as the 36 and 36 SL models. This is securely bolted to the fork crown and below the sealing flange via new mounting points, without interfering with the bleed valves.
Key data and options at a glance
The Fox 38 is offered for both 29-inch and 27,5-inch wheels. Riders can choose between 44 and 37 millimeters of offset. The front wheel is held in place by a floating 15 x 110 millimeter Boost thru-axle. Tire clearance is generous, accommodating tires up to 2,6 inches wide.
Braking is handled as standard with 200-millimeter discs (for 29-inch wheels) or 180-millimeter discs (for 27,5-inch wheels) using the post-mount method. For those who want maximum braking power, the diameter can be increased to up to 230 millimeters. Of particular interest to e-mountain bikers: Fox will soon offer the fork with a direct ABS mounting option.
Outlook: The Fox 38 in practice
With the new generation of the Fox 38, the Americans impressively demonstrate that even an extremely successful and proven product still offers room for technological advancement. Instead of simply blindly increasing stiffness and travel, details such as the intentional torsional flex, the flexing Glidecore air spring, and the extended bushings testify to a deep understanding of the real challenges of enduro racing. On paper, the innovations certainly sound like a noticeable upgrade in grip, traction, and rider comfort.
Whether the calculations actually work out on the trail and whether the bike feels noticeably more planted on tough descents is something we're currently putting to the test. A detailed practical test of the new Fox 38 will be published here in the coming weeks!