The Fox 38 Factory GRIP2 is built to handle aggressive enduro and downhill riding. Designed with precision damping, oversized stanchions, and a feature-rich damper, this fork appeals to riders pushing their limits on technical terrain. This guide breaks down everything you need to know about installing, adjusting, maintaining, and optimizing the 38 Factory GRIP2 for high-performance trail use.
Tools Required
- Torque wrench [paid link] (Nm scale)
- Crown race setting tool
- Allen wrenches [paid link] (4mm, 5mm, 6mm)
- Shock pump
- Suspension grease
- Caliper alignment tool
- Oil syringe and suspension fluid (as specified by Fox)
- Clean rags and isopropyl alcohol
Installation Guide for the 38 Factory GRIP2
Installing the Fox 38 Factory GRIP2 requires attention to detail to ensure structural integrity and performance. Begin by confirming steerer tube length and crown race compatibility. If transferring from another fork, a proper crown race extractor is recommended to avoid damage.
Insert the steerer into the headtube and secure the stem using the manufacturer-recommended torque settings. Align the fork with the front wheel and ensure the brake caliper mounts align with the rotor. Attach the brake caliper loosely, then center it over the rotor using a caliper alignment tool before tightening bolts evenly.
Attach the front wheel and torque the axle to the specified 19.7 Nm. Use the pinch bolt system on the lowers to stabilize the axle, tightening each bolt to 5.1 Nm. Conduct a preload check and cycle the fork before your first ride.
Adjusting the GRIP2 Damper Settings
The GRIP2 damper is one of Fox’s most tunable systems, offering high and low-speed compression and rebound adjustments. Start with the factory-recommended base settings and refine from there based on terrain and rider weight.
Low-speed compression controls ride feel on slow inputs like pedaling. High-speed compression addresses impacts from rocks and roots. Rebound settings dictate how fast the fork returns after compression, affecting traction and control.
Tuning should be performed in small increments. If rebound feels too fast, the front end may feel loose on landings. Too slow, and the fork will pack down over successive hits. Use Fox’s tuning guide to match sag and damping characteristics to your weight and riding style.
Routine Maintenance and Service Intervals
Regular maintenance keeps the 38 Factory GRIP2 running smoothly and extends its lifespan. Fox recommends a 50-hour lower leg service that includes cleaning and lubrication. Inspect dust wipers and foam rings for wear, and replace if degraded.
At the 125-hour mark, a full damper and air spring service is necessary. This requires draining and refilling the damper oil, greasing the air spring, and replacing internal seals. Always use genuine Fox parts and fluids to maintain optimal performance.
Additionally, regularly check for creaks or play in the steerer and crown area, as the larger chassis of the 38 can highlight headset or frame interface issues.
Troubleshooting Common Set-Up Issues
Many issues with the GRIP2 fork stem from improper setup rather than mechanical faults. If the fork feels harsh, check for over-inflated air pressure or overly closed compression settings. Excess dive under braking typically indicates insufficient low-speed compression or air volume.
Another frequent problem is inconsistent rebound. Ensure that the rebound dials are not over-adjusted or misaligned. If your fork is losing travel or feels sticky, inspect the air spring for proper lubrication and remove excess grease that may block negative pressure transfer.
If damper performance fades on long descents, it may be due to heat build-up or air contamination in the oil circuit—both resolved by a damper service.
Customization and Performance Optimization
The GRIP2’s high level of adjustability makes it a platform for fine-tuning. Riders can customize performance using volume spacers in the air spring. Reducing spacers increases travel linearity, suitable for lighter riders or smoother trails. Adding spacers boosts progression, ideal for big hits and aggressive lines.
Fox’s floating axle system also allows slight tuning of fork stiffness by adjusting preload on the lowers, a feature especially beneficial for riders on mixed-terrain enduro courses. Optimizing tire pressure in tandem with suspension tuning can unlock further performance improvements.
Riders can also install aftermarket SKF low-friction seals for improved small bump sensitivity without compromising seal durability.
Comparison with Similar Models
Compared to the Fox 36 Factory GRIP2, the 38 offers increased stiffness and better control for heavier or more aggressive riders. The 38’s beefier chassis handles steeper and rougher trails with more confidence, although it adds around 200 grams of weight.
In contrast, the RockShox ZEB Ultimate is the closest competitor. The ZEB provides a similar 38mm stanchion chassis and offers the Charger 3 damper. While the ZEB is often praised for its supple initial stroke, the GRIP2 holds an edge in adjustability and mid-stroke support.
Ultimately, the Fox 38 GRIP2 excels in precise tuning, structural integrity, and race-proven performance, whereas other models might favor simplicity or marginal weight savings.
Component Compatibility and Integration
The 38 Factory GRIP2 uses a 15x110mm Boost axle and is compatible with both 29” and 27.5” wheels (with the appropriate version). It fits tapered steerer tubes and flat-mount brake interfaces. Ensure your frame accommodates the 180mm minimum rotor size required by Fox.
For drivetrain integration, the fork accommodates full internal routing via optional cable guides. It also pairs well with Fox’s electronically-controlled Live Valve system, although a manual GRIP2 setup remains the standard for most riders.
The air spring can be modified for travel ranging from 160mm to 180mm, making it a flexible choice across a variety of bike setups.
FAQs
1. What is the recommended sag setting for the Fox 38 Factory GRIP2?
Fox recommends 15-20% sag for enduro applications. Adjust sag by inflating the air spring and checking the o-ring position after compression.
2. Can I use the Fox 38 Factory on a trail bike?
While possible, the fork’s weight and stiffness are optimized for enduro or downhill. Trail bikes may feel overbuilt with this fork.
3. How often should I service the GRIP2 damper?
A full damper service is recommended every 125 riding hours, or sooner if performance fades or oil contamination is suspected.
4. Is the Fox 38 compatible with Fox’s Live Valve system?
Yes, the 38 chassis is Live Valve compatible, but most GRIP2 models are manually adjustable.
5. How do I reduce brake dive on this fork?
Increase low-speed compression or add volume spacers to make the air spring more progressive, reducing dive under hard braking.
6. Does the Fox 38 come with a floating axle?
Yes, all current Fox 38 Factory models come with a floating axle to improve alignment and reduce friction.
Conclusion
The Fox 38 Factory GRIP2 stands out as a leading suspension fork for serious mountain bikers demanding precision, strength, and customization. Its advanced GRIP2 damper, robust 38mm chassis, and progressive air spring offer a performance edge in technical descents and enduro racing. While it may be overbuilt for casual riders, for those seeking uncompromised performance, the 38 Factory GRIP2 is hard to beat.