The Fox 38 Factory GRIP2 is a high-performance suspension fork designed for aggressive trail, enduro, and e-MTB applications. Equipped with the GRIP2 damper featuring Variable Valve Control (VVC), this fork demands precise maintenance to preserve its advanced damping performance and long-term durability. This guide outlines a full home-service procedure, covering installation preparation, periodic maintenance, troubleshooting, performance tuning, and compatibility insights specific to the 38 Factory GRIP2.
Tools Required
- 32 mm cassette tool (for air spring top cap)
- 10 mm socket wrench
- 6 mm and 2 mm hex keys [paid link]
- Torque wrench [paid link]
- Pick tool or small flathead screwdriver
- Suspension-specific grease
- Suspension oil (Fox 20wt Gold, Float Fluid)
- Clean lint-free cloths
- Oil measuring syringe or graduated cylinder
- Isopropyl alcohol (for cleaning)
- Soft-jawed vice (optional for damper disassembly)
Initial Setup and Installation
Before installing the 38 Factory GRIP2, ensure your bike’s frame and headset are compatible with the fork’s steerer tube and axle spacing. The 38 uses a tapered steerer and 110 mm Boost spacing.
Trim the steerer to match your headtube stack height and install a star nut or threaded insert as needed. Carefully torque the stem bolts to manufacturer specifications to prevent overclamping the steerer. Verify brake caliper alignment for the 203 mm post-mount standard. Use a torque wrench [paid link] on the pinch bolts and axle to ensure proper preload on the floating axle system.
Routine Maintenance Schedule
Fox recommends lower leg service every 50 hours of riding and a full damper and air spring overhaul every 125 hours. Following this schedule maintains performance and prevents premature wear. Always record your service intervals and riding conditions for reference.
Lower Leg Service Procedure
Start by removing the front wheel and brake caliper. Loosen the foot nuts (6 mm hex) and gently tap them to disengage the shafts. Drain oil from the fork by inverting it over a catch pan.
Once drained, slide off the lowers. Clean all bushings, seals, and the inner legs thoroughly using isopropyl alcohol and lint-free cloths. Inspect wiper seals for cracking or deformation. If replacing, use a proper seal press.
Lubricate the dust wipers with suspension grease and apply fresh 20wt Gold oil inside the lower legs—typically 20 cc per leg. Reinstall the lowers by sliding them evenly over the stanchions and tightening the foot nuts to Fox’s torque spec (5.1 Nm). Reinstall the axle and brakes, then cycle the fork through its travel to distribute oil.
Air Spring Maintenance and Overhaul
To service the air spring, remove the top cap using a 32 mm socket and depressurize the system via the Schrader valve. Use a pick tool to unclip the retaining ring and slide out the air shaft. Inspect the shaft, seals, and spacers. Replace worn o-rings and lubricate all moving parts with suspension grease.
Reassemble by reversing the process, ensuring the top cap is torqued to 28.3 Nm. Inflate to your desired pressure and check sag for proper setup. Use volume spacers to fine-tune the spring curve based on your terrain and riding style.
GRIP2 Damper Servicing and Adjustments
The GRIP2 damper is a sealed cartridge that requires internal servicing by a trained technician or confident home mechanic with damper tools. However, you can adjust external compression and rebound with 2 mm and 6 mm hex keys [paid link]. Each click makes a noticeable change due to the high-resolution valving.
For riders seeking maximum traction, begin with open settings and increase compression as needed. Use a stopwatch to dial in rebound relative to fork extension time. Fox’s baseline setup chart offers a great starting point but always tune to personal feedback.
Troubleshooting Common Issues
If you experience harsh top-out, check for improper air pressure or dry top-out bumpers. Inconsistent rebound may indicate air mixing in the damper—requiring a cartridge bleed. Oil weep around the seals typically suggests contamination or aged wipers. A knocking sensation often results from under-torqued foot nuts or worn bushings.
Always inspect torque settings and ride characteristics after reassembly. Minor noises can be cured with fresh lubrication and proper preload.
Performance Customization Options
The 38 Factory GRIP2 supports volume tuning with clip-in spacers to shape the air spring curve. Aggressive riders can add spacers for increased ramp-up, while lighter riders may benefit from removing spacers for linear performance.
Additionally, VVC adjustments on both high-speed compression and rebound circuits allow micro-level control without opening the damper. Riders competing or descending frequently can use this to maximize grip under braking and over chatter.
Compatibility with Other Drivetrain Components
The 38 Factory GRIP2’s Boost axle and 203 mm post-mount brake standard must align with your frame and wheel hub. It accepts both 29” and 27.5” wheels depending on the model variant. The floating axle ensures alignment with hub width but may require re-spacing for certain hubs.
Cable routing accommodates electronic or mechanical drivetrains, and the arch shape allows adequate clearance for oversized head tubes and modern frame designs. Always ensure fork offset (44 mm or 51 mm) matches your frame’s intended geometry.
Model Comparison: 38 Factory GRIP2 vs. Fox 36 Factory GRIP2
The Fox 38 is designed for more aggressive use than the 36, with thicker stanchions (38 mm vs. 36 mm) and a heavier-duty crown and chassis. While both use the GRIP2 damper and similar air spring systems, the 38 offers better stiffness under braking and high-speed impacts.
For riders pushing into enduro territory or using an e-MTB, the 38 provides superior confidence and durability. However, the 36 remains a better option for trail and lightweight applications.
FAQs
Q1: How often should I service my Fox 38 Factory GRIP2 fork?
A: Perform a lower leg service every 50 hours and a full overhaul at 125 hours of riding.
Q2: Can I change travel on the 38 GRIP2?
A: Yes, travel adjustments require changing the air spring assembly to the desired stroke length.
Q3: What oil goes into the 38 Factory GRIP2?
A: Use Fox 20wt Gold for the lower legs and Float Fluid for the air spring seals.
Q4: What does VVC mean on the GRIP2 damper?
A: Variable Valve Control allows high-speed compression and rebound tuning without disassembly.
Q5: Why does my fork feel sticky after service?
A: This may be due to over-greasing, contaminated oil, or dry bushings—re-clean and re-lubricate accordingly.
Q6: Can I install this fork on my non-Boost frame?
A: No, the 38 Factory GRIP2 is designed specifically for Boost 110 mm spacing.
By following this guide, riders can confidently maintain and tune their 38 Factory GRIP2 suspension fork, ensuring consistent performance and extending its lifespan on the trail.