The Fox 38 Factory GRIP2 fork is a high-performance suspension fork engineered for aggressive trail, enduro, and downhill riding. Its advanced GRIP2 damper system offers unmatched adjustability and tunability for serious riders. However, to fully leverage its potential, proper setup, tuning, and maintenance are essential. This guide provides detailed technical instructions tailored specifically for the 38 Factory GRIP2, focusing on setup, tuning, troubleshooting, and performance optimization.
Tools Required
- Shock pump (digital preferred)
- 3mm, 4mm, 5mm Allen wrenches [paid link]
- Torque wrench [paid link]
- Suspension oil and seals (for maintenance)
- Isopropyl alcohol and clean rags
- O-ring or zip-tie for sag measurement
Understanding the GRIP2 Damper System
The GRIP2 damper in the Fox 38 Factory is a high-end, closed cartridge damper featuring Variable Valve Control (VVC). It provides four-way independent adjustability:
- High-speed compression (HSC)
- Low-speed compression (LSC)
- High-speed rebound (HSR)
- Low-speed rebound (LSR)
This configuration allows fine-tuning for terrain and rider preference, offering a customizable ride quality.
Setting Up Sag and Air Pressure
Sag is the percentage of total fork travel used when the rider is seated in a neutral position. For the 38 Factory, a 15–20% sag is ideal for aggressive trail and enduro applications.
Begin by:
- Setting the fork pressure according to the rider’s weight. Use Fox’s official air pressure chart as a starting reference.
- Placing the O-ring on the fork stanchion and having the rider get into attack position.
- Checking sag and adjusting air pressure in small increments to match the desired range.
Ensure the rider’s gear is worn during the setup to achieve realistic weight distribution.
Adjusting Compression and Rebound
Compression Adjustments
The compression dials are located on top of the right fork leg:
- HSC (outer blue dial) – Controls the fork’s resistance to fast, heavy impacts like drops and big hits. Turn clockwise to firm.
- LSC (inner black dial) – Regulates fork motion during body movement like pedaling and cornering. Clockwise firming improves support.
Start with factory baseline settings (typically 8 clicks out from closed) and fine-tune in 1–2 click increments after trail testing.
Rebound Adjustments
The rebound controls are found at the bottom of the right leg:
- HSR (red dial) – Affects recovery after hard compressions. Too fast can make the fork bounce; too slow can pack the suspension.
- LSR (black dial) – Manages recovery after small bumps and rider inputs.
Start rebound adjustment with 10 clicks out and modify based on trail feedback. Aim for a controlled return without excessive oscillation.
Troubleshooting Common Setup Issues
Fork Feels Harsh or Stiff
This typically results from excessive air pressure or over-firmed compression settings. Reduce air pressure slightly or back out the HSC dial 1–2 clicks.
Fork Packs Down on Successive Hits
Often caused by rebound set too slow. Open up the HSR by 1–2 clicks and retest on rough terrain.
Fork Bobs Excessively While Climbing
The LSC may be too open. Firm it by a few clicks to increase mid-stroke support during climbs and cornering.
Maintenance Schedule and Procedures
Routine maintenance extends fork life and maintains performance. Fox recommends:
- Every 30 hours – Clean stanchions, inspect seals, check for oil residue.
- Every 50 hours – Replace lower leg oil and clean foam rings.
- Every 100 hours – Full damper service, including seals and oil bath replacement.
Use only Fox-approved suspension fluid and follow torque specs. Cleanliness is crucial—work in a dust-free environment.
Optimizing Performance for Riding Styles
Enduro Racing
Prioritize a firmer HSC setting and slightly faster rebound to handle aggressive terrain at high speed. Match sag to the lower end of the 15–20% range for better support.
Trail Riding
Use a balanced midrange setting for both compression and rebound. Allow more sag (~20%) to enhance comfort on varied terrain.
Bike Park Use
Firm up HSC and LSC significantly. Set rebound for faster recovery to handle frequent jumps and drops. Regular maintenance is critical due to higher usage intensity.
Customization Options
The 38 Factory GRIP2 can be personalized beyond damper settings:
- Volume Spacers – Alter air spring progression. More spacers increase bottom-out resistance. Ideal for aggressive riders.
- Decal Kits – Aesthetic customization with factory color-matched kits.
- Axle Options – Choose between standard or quick-release lever options based on convenience preferences.
Compatibility With Drivetrain and Chassis
The 38 Factory is designed for modern aggressive trail and enduro bikes with 160–180mm travel. It features:
- 29” and 27.5” wheel compatibility.
- Boost axle spacing (15x110mm).
- 44mm or 51mm rake options to match various frame geometries.
Ensure headset and frame compatibility with 1.5” tapered steerer tube. Check brake rotor clearance (203mm+ recommended) for proper fitment.
Comparing the 38 Factory GRIP2 With Other Fox Models
38 Performance Elite GRIP2
Shares the same damper and chassis but lacks Kashima coating, slightly reducing small bump sensitivity.
36 Factory GRIP2
Lighter and more suitable for trail bikes. Less stiffness than the 38, which may impact descending confidence on steep terrain.
40 Factory GRIP2
A dual-crown fork for downhill-specific bikes. Provides ultimate stiffness and travel but at the cost of weight and maneuverability.
Choose the 38 Factory GRIP2 if you seek the balance of enduro-capable performance with unmatched adjustability and chassis stiffness.
Frequently Asked Questions (FAQs)
1. How many clicks of adjustment does the GRIP2 damper offer?
Each adjuster typically offers around 16 clicks, allowing for highly precise tuning across all four parameters.
2. Can I use the 38 Factory GRIP2 on a trail bike?
Only if the bike is designed to handle 160mm+ travel and a 38mm chassis. Over-forking a light trail frame can compromise geometry and handling.
3. How do I know if I need volume spacers?
If you’re bottoming out frequently even at recommended pressure, adding volume spacers will increase end-stroke ramp-up.
4. Is the GRIP2 damper user-serviceable?
Fox recommends professional servicing for internal damper work, though basic oil changes and seal replacements are user-manageable.
5. What’s the recommended torque for axle and pinch bolts?
Axle: 19.7 Nm, Pinch bolts: 7.3 Nm. Always use a calibrated torque wrench [paid link] to prevent damage.
6. Can I upgrade my GRIP damper to GRIP2?
Yes, Fox offers upgrade kits compatible with certain chassis models. Ensure your fork’s internals and year are supported.
Conclusion
The Fox 38 Factory GRIP2 fork represents the pinnacle of suspension performance for aggressive riders. With its four-way independent damping and stiff chassis, it excels in demanding terrain. Proper setup, diligent maintenance, and understanding of each adjuster’s impact on ride quality are key to unlocking its full potential. By following this guide, beginners and experienced riders alike can optimize their fork to match their riding style and terrain demands.