The Fox 38 Factory GRIP2 suspension fork is engineered for aggressive enduro and gravity riders who demand maximum performance from their front suspension. Built around a 38mm stanchion chassis and featuring the advanced GRIP2 damper, this fork is the top-tier choice for technical descents and enduro racing. This guide details its installation, tuning, and maintenance, while providing critical insights into its performance features, compatibility, and how it compares to other forks in its category.
Tools Required
- Torque wrench [paid link] with 5mm and 6mm hex bits
- Crown race setter
- Star nut setter (if using a traditional headset)
- Shock pump (up to 300 psi)
- Suspension grease (Fox Float Fluid recommended)
- Allen keys [paid link] (4mm–6mm)
- Flat blade screwdriver
- Digital caliper [paid link] (for accurate spacer and steerer tube cutting)
Installation Guidelines for the 38 Factory GRIP2
Installing the 38 Factory GRIP2 fork requires precision and the correct sequence to ensure safe and optimal performance.
First, begin by prepping the steerer tube. Measure your head tube and headset stack height accurately. Cut the steerer accordingly, allowing 3–5mm for the top cap clearance above the stem. Use a sharp saw guide to avoid uneven cuts.
Install the star nut using a specific setter tool, ensuring it is centered and fully inserted. Then, press the crown race onto the fork’s crown base using a crown race setting tool.
Insert the fork into the head tube and slide on the headset spacers and stem. Lightly tighten the top cap bolt to preload the headset bearings. Align the stem and torque the stem bolts to the recommended 5–6 Nm.
Attach the brake caliper using a 180mm or 203mm post mount adapter, depending on your rotor size. Route the brake hose through the integrated channels on the fork’s arch if present, then zip-tie securely.
Finally, install the front wheel and torque the axle to 19.7 Nm. Engage the pinch bolts to 5.1 Nm to secure the axle.
Tuning and Adjustment of the GRIP2 Damper
The GRIP2 damper is central to the performance of the Fox 38 Factory. It provides independent high- and low-speed compression and rebound adjustments, allowing riders to fine-tune their ride for any terrain.
To begin tuning, set the sag using your rider weight. A baseline of 20–25% sag is recommended. Use a shock pump to adjust air pressure in the EVOL air spring accordingly.
Use the low-speed compression dial to control fork dive under braking and cornering. Adjust this by turning the knob clockwise for more support or counterclockwise for more plushness.
High-speed compression can be tuned to resist harsh bottom-outs. Turn the blue dial clockwise to increase support for big hits.
Rebound adjustment is done in two stages. The red dial controls low-speed rebound for trail chatter, while the smaller knob fine-tunes high-speed rebound recovery from large impacts.
Experiment with gradual changes and test on your usual trail to achieve your preferred setup.
Routine Maintenance Requirements
Regular maintenance ensures consistent performance and extends the life of your Fox 38 Factory GRIP2 fork. Fox recommends lower leg service every 50 riding hours and a full damper service every 125 hours.
To perform lower leg maintenance, remove the fork from the bike and unscrew the bottom bolts. Carefully slide off the lower legs and clean out old oil and debris.
Inspect wiper seals and foam rings for wear. Replace if necessary and soak new foam rings in Fox Float Fluid. Apply a thin layer of suspension grease to the stanchions before reassembly.
Add the specified 40ml of Float Fluid to the lower legs before reattaching. Torque the lower leg bolts to 5.1 Nm and reinstall the fork.
Performing this routine will keep the fork moving smoothly and prevent premature wear of the internals.
Troubleshooting Common Issues
Air Loss or Pressure Drop: If your fork is losing air, check for leaks around the Schrader valve. Replace the valve core if needed and inspect the air sleeve O-rings for wear.
Harsh Ride or Lack of Sensitivity: Confirm that the sag is properly set and the rebound is not too slow. Also, clean and lubricate the seals if the fork feels sticky.
Oil Leaks: This can be caused by worn seals or overfilled oil chambers. Perform a lower leg service to inspect and remedy the issue.
Creaking at the Crown: This is often due to dry interfaces between the steerer tube and the crown. Disassemble, clean, and re-grease the crown race and headset spacers.
Optimizing the Fork for Performance
To get the most out of your Fox 38 Factory GRIP2, customize the air spring curve using volume spacers. Adding spacers increases progression, giving more support at the end of the stroke.
The stock fork comes with one or two volume spacers, depending on travel. Riders seeking a more playful and poppy feel can reduce spacers, while those needing bottom-out resistance can add more.
Monitor your compression and rebound settings using the rider telemetry app or keep a tuning log to track changes and preferences over time.
Pairing the fork with a properly tuned rear shock and balanced suspension setup will also enhance its overall performance.
Compatibility with Other Drivetrain and Frame Components
The 38 Factory GRIP2 is compatible with 29” and 27.5” wheel setups depending on the model variant. It supports boost hub spacing (15x110mm) and integrates cleanly with modern frame geometries featuring 44mm or 56mm head tubes.
It pairs well with headsets from Cane Creek, FSA, and Hope. Brake compatibility includes both Shimano and SRAM post-mount calipers, with sufficient arch clearance for 203mm rotors.
The fork uses a tapered steerer and is best matched with high-end enduro or gravity-focused frames. Ensure axle-to-crown measurements and rake (44mm or 51mm) align with frame design for optimal handling.
Comparing the 38 Factory GRIP2 to Other Forks
When compared to the Fox 36 Factory GRIP2, the 38 offers stiffer chassis and better heat dissipation, making it ideal for enduro racing. The increased stanchion diameter reduces flex and improves steering precision under load.
Against the RockShox ZEB Ultimate, the 38 has superior small bump compliance thanks to its EVOL air spring and fine-tuned damper. However, ZEB’s DebonAir+ spring offers a smoother mid-stroke feel for some riders.
The 38 also stands out for its advanced adjustability, giving riders more control over every damping aspect. This makes it a better choice for riders who frequently tweak their setup based on trail conditions.
Frequently Asked Questions (FAQs)
1. How much travel does the Fox 38 Factory GRIP2 offer?
It is available in travel options from 160mm to 180mm, depending on the specific model.
2. Can I install the 38 Factory on a trail bike?
It’s not recommended unless the bike is rated for the extra weight and axle-to-crown height, which may affect geometry and handling.
3. How often should I service the fork?
Lower leg service should be performed every 50 hours, and a full damper overhaul every 125 hours of riding.
4. What is the weight of the 38 Factory GRIP2?
The fork weighs approximately 2,270g (5.0 lbs) depending on the steerer length and travel configuration.
5. Is the 38 Factory compatible with coil conversions?
Currently, the 38 Factory is air-spring specific and does not support coil conversions officially from Fox.
6. What type of riding is the 38 Factory GRIP2 best for?
It is designed for enduro, aggressive trail, and downhill-adjacent riding where stiffness and control are prioritized.