The Fox 38 Factory GRIP2 suspension fork is a high-performance component designed specifically for aggressive enduro and trail riders who demand precision, stiffness, and tunability. Built with a robust 38mm stanchion chassis and the renowned GRIP2 damper, this fork is engineered to offer superior traction, control, and compliance in the most demanding terrain. In this guide, we will explore its installation, tuning, maintenance procedures, and how it compares with similar offerings on the market.
Tools Required
- Torque wrench [paid link] (preset to Fox-recommended Nm specs)
- Allen key set (2mm–8mm)
- Shock pump
- Suspension grease
- Torque specs chart (from Fox technical manual)
- Clean rags and isopropyl alcohol
- Crown race setting tool (if applicable)
Installation of the 38 Factory GRIP2 Fork
Before installing the 38 Factory GRIP2 fork, it’s essential to ensure the head tube is properly prepped, and the correct steerer tube length is measured.
First, cut the steerer tube to the appropriate length, allowing for headset stack and stem height. Carefully install the crown race on the steerer base using a race setting tool, ensuring it seats flush. Slide the steerer through the headset bearings and secure the fork using the stem and top cap assembly, torquing to specification. Be sure the headset preload is snug but does not bind the steering.
Axle installation is straightforward due to the 15QR system. Insert the wheel, align it properly, and thread the axle fully before tightening the pinch bolt using a torque wrench [paid link]. Do not overtighten, as this can deform the dropout interface.
Suspension Tuning and Adjustment
The GRIP2 damper provides independent high- and low-speed compression and rebound adjustments, making it highly tunable for varied terrain and rider preferences.
Begin by setting the correct sag. Using a shock pump, pressurize the air spring to match rider weight and riding style. Use the O-ring on the stanchion to set 20–30% sag when seated in riding position. Adjust rebound based on rider weight using Fox’s base setting guide, then fine-tune by feel over multiple rides.
High-speed compression controls impact response from sharp hits. Riders in rough terrain can add clicks for stability. Low-speed compression impacts mid-stroke support and pedaling efficiency; reduce it for plushness or increase for better trail feedback. Rebound adjustment must balance return speed—too fast leads to pogoing; too slow causes packing.
Maintenance and Service Intervals
Routine service of the 38 Factory GRIP2 ensures long-term performance. Fox recommends a lower leg service every 50 hours of ride time.
To begin, remove the lowers by loosening the foot nuts and gently tapping them to release the seals. Drain the old oil, inspect bushings, and clean internals with isopropyl alcohol. Re-grease the dust wipers and foam rings with suspension-specific grease. Refill with the manufacturer-specified volume of suspension oil before reinstalling the lowers.
At 125-hour intervals, a full damper and air spring service is recommended. This requires damper bleeding, air spring disassembly, and internal part inspection. If unfamiliar, this procedure is best left to certified suspension technicians due to the complexity of GRIP2 internals.
Troubleshooting Common Setup Issues
Improper setup can lead to poor ride quality and inconsistent suspension behavior. One common issue is excessive fork dive under braking, typically due to insufficient low-speed compression or low air pressure. Increase LSC or add volume spacers to address this.
Another frequent concern is a harsh top-out clunk, often the result of too little rebound damping or excessive air pressure. Dial in more rebound clicks and reduce air pressure slightly while observing sag.
Creaking at the crown steerer junction is a known concern on heavily used forks. This requires professional inspection and potentially a crown-steerer assembly replacement.
Customization and Performance Optimization
The 38 Factory GRIP2 can be tailored for different ride characteristics using volume spacers, which adjust the air spring’s progressiveness. Aggressive riders may prefer more spacers for bottom-out resistance, while lighter or less aggressive riders may benefit from a linear curve with fewer spacers.
Upgrading to Kashima-coated stanchions, which the Factory model includes, reduces friction and improves small bump compliance. Additional upgrades such as SKF low-friction wiper seals enhance sensitivity.
Riders can also fine-tune performance with hybrid spring conversions or aftermarket damper cartridges, although these may void warranties and require expert installation.
Compatibility With Other Drivetrain and Frame Components
The Fox 38 Factory GRIP2 is compatible with modern 29” and 27.5” enduro frames using tapered head tubes. The axle spacing supports Boost (110mm), ensuring compatibility with contemporary enduro wheels. It uses a post-mount disc brake system that fits rotors up to 203mm or more with adapters.
Clearance must be checked for fender or frame interference, especially with longer travel options. The fork’s chassis accommodates larger tire volumes, but frame limitations may restrict actual use.
Drivetrain compatibility is not typically a concern, though riders should ensure brake hose routing and control lever placement align cleanly with cockpit setup, especially when using remote lockouts or integrated shift levers.
Comparison With Similar Models
Compared to the Fox 36, the 38 offers a stiffer chassis with larger 38mm stanchions, ideal for heavier or more aggressive riders. It sacrifices a small amount of compliance in exchange for enhanced steering precision.
Versus the RockShox ZEB Ultimate, the Fox 38 delivers more tunability via its GRIP2 damper. The ZEB offers a slightly more supple initial stroke, but the Fox excels in mid-stroke support and adjustability. The GRIP2 damper outperforms RockShox’s Charger 3 in terms of independent damping control.
The Öhlins RXF38 presents similar stiffness with a different damper philosophy, prioritizing plushness over aggressive tuning. Riders seeking pure downhill capability may favor the Fox 38, especially when paired with an X2 or DHX2 rear shock.
Conclusion
The Fox 38 Factory GRIP2 is a benchmark in enduro suspension performance. Its robust construction, wide-ranging tunability, and high-end damper design make it a top choice for riders pushing the limits on technical trails. Regular maintenance and thoughtful setup are key to extracting its full potential, while its compatibility and customization options provide flexibility across many modern builds. Whether upgrading from a lighter chassis or building a race-ready enduro rig, the 38 Factory GRIP2 delivers precision and control at the highest level.