The Float 40 Factory eMTB by Fox is a high-performance downhill and eMTB-specific suspension fork designed for aggressive riding. With its sophisticated GRIP2 damper and EVOL air spring, this model demands precise and regular maintenance to maintain optimal performance. Whether you’re tackling rugged descents or long technical trails, keeping your Float 40 Factory fork in peak condition enhances control, comfort, and longevity.

Tools Required

• 32mm or 40mm socket (depending on lower leg bolts)
• Torque wrench [paid link]
• Suspension fork oil (Fox 20wt Gold recommended)
• Isopropyl alcohol and clean rags
• Seal driver kit
• Pick or dental tool
• Measuring syringe or oil measuring cup
• Suspension pump
• Nitrile gloves
• Allen wrenches [paid link] (2mm to 6mm)
• Clean workspace with bike stand [paid link]

Installation Guidelines for the Float 40 Factory eMTB

Proper installation of the Float 40 Factory eMTB fork ensures reliable performance from the first ride. Begin by verifying steerer tube length and fork travel compatibility with your frame. When cutting the steerer tube, always leave sufficient length for spacers and the stem to avoid excessive preload on the headset.

Apply a thin layer of grease to the crown race seat before installing the crown race. When mounting the fork, torque all headset components to the manufacturer’s specification. Carefully align the brake caliper to prevent rotor rub and ensure smooth brake operation. Always route the brake hose cleanly through the fork’s designated guides, and double-check the clearance with the front tire and frame.

Suspension Setup and Adjustment

The Float 40 Factory offers an advanced setup through its GRIP2 damper, which includes high- and low-speed compression and rebound adjustments. Start by setting the sag using the EVOL air spring. A typical range is 15–20% of total travel for eMTB use, and fine-tuning this setting based on rider weight and terrain preference is essential.

Use the suspension pump to dial in the correct air pressure. Then adjust rebound to control the return speed of the fork after impacts—faster for smooth terrain, slower for technical descents. Compression settings allow you to stiffen or soften the fork’s initial stroke (low-speed) and deeper travel resistance (high-speed), giving you control over small bump sensitivity and harsh landings.

Routine Maintenance Schedule

Regular maintenance extends the life of the Float 40 Factory and ensures consistent damping and support:

• Every 20 hours: Wipe down the stanchions, inspect dust wipers, and check for oil residue or debris buildup. Lubricate stanchions with a suspension-specific fluid.
• Every 50 hours: Perform a lower leg service. This includes removing the lowers, replacing bath oil, and cleaning foam rings and seals.
• Every 125 hours: Conduct a full damper and air spring service. This involves disassembling the air spring, replacing seals, and servicing the damper cartridge according to Fox’s internal service guide.

Troubleshooting Common Setup Issues

Several performance issues may stem from incorrect setup or worn components:

• Harsh ride over small bumps: Typically indicates insufficient sag or excessive compression damping. Adjust air pressure and reduce low-speed compression.
• Fork packing down on repeated hits: Suggests slow rebound settings. Open up the rebound adjuster to increase fork responsiveness.
• Oil leakage near the seals: Worn dust wipers or foam rings can cause this. Replace them immediately and clean internal surfaces.
• Noisy or inconsistent travel: Often caused by trapped air in the damper or dry seals. A full service is required to restore smooth operation.

Deep Cleaning and Lubrication Process

For a thorough clean, remove the lower legs by loosening the axle and lower bolts, then gently slide the legs off. Drain and measure the old bath oil, clean all parts using isopropyl alcohol, and inspect foam rings, bushings, and wipers for wear. Re-lubricate with fresh Fox 20wt Gold oil, ensuring correct oil volume is added to each leg. Carefully reinstall the lowers, ensuring they engage the damper and air shafts properly.

Seal and Wiper Replacement Tips

Use a proper seal driver to avoid damaging the fork lowers when installing new seals. Soak foam rings in suspension oil before fitting them beneath the wipers. Lightly grease the new dust wipers with suspension grease to reduce initial friction and ensure better seal life.

Air Spring Maintenance and Tuning

The EVOL air spring enhances small bump compliance and mid-stroke support. During maintenance, remove the top cap, clean the air chamber, and inspect for internal wear. Use volume spacers to adjust progressiveness—more spacers provide firmer ramp-up ideal for aggressive riding, while fewer spacers result in a more linear feel.

GRIP2 Damper Care and Service

To service the GRIP2 damper, it must be removed and opened in a clean, controlled environment. Replace oil and seals as per service intervals. Pay special attention to the bladder system inside the damper, as it regulates backpressure and performance consistency. Any unusual behavior like inconsistent compression or clicking sounds warrants a complete damper rebuild.

Performance Customization and Tuning

The Float 40 Factory eMTB supports fine-tuning for diverse riding styles:

• Riders prioritizing grip and comfort: Opt for lower compression and rebound damping with higher sag.
• Aggressive descenders: Stiffen compression and add volume spacers to prevent bottoming.
• Mixed terrain riders: Balance mid-stroke support with moderate rebound to handle transitions efficiently.

Compatibility with Drivetrain and Frames

This fork is tailored for long-travel eMTBs and gravity-focused setups. It pairs best with sturdy frames featuring 1.5” tapered head tubes. Ensure axle spacing (typically 20x110mm Boost) aligns with your front hub. It is not directly affected by drivetrain configurations, but consider fork offset and crown clearance when pairing with mullet or 29” setups.

Float 40 Factory vs. Similar Fork Models

Compared to the Fox 38 Factory, the Float 40 offers dual crown stiffness and superior control for DH-specific and heavy-duty eMTB applications. While the 38 is lighter and more versatile, the 40 excels in extreme descents and heavier riders. Riders looking for cross-platform performance might prefer the Fox 38, but those needing maximum stiffness and responsiveness should stick with the 40.

Best Practices for Storage and Off-Season Care

When storing your Float 40 Factory for extended periods, depressurize the air spring slightly to relieve internal seal pressure. Store the bike vertically to prevent oil pooling in one leg. Before your first ride after storage, cycle the fork several times manually and inspect seals and damping response.

Signs Your Fork Needs Professional Service

Even with DIY upkeep, some symptoms indicate the need for expert servicing:

• Loss of damping or fork “bottoming out” with minimal force.
• Excessive bushing play or creaking from the crown area.
• Inconsistent rebound or compression after adjustment.
• Visual damage to stanchions or lower legs.

Seek a certified Fox technician if these issues persist despite regular maintenance.

FAQs

1. How often should I service my Float 40 Factory eMTB fork?
You should perform basic cleaning every 20 hours, a lower leg service every 50 hours, and a full rebuild every 125 hours of riding.

2. What oil should I use for a lower leg service?
Fox recommends using 20wt Gold suspension fluid in the lower legs to maintain optimal performance and seal lubrication.

3. Can I adjust travel on the Float 40 Factory fork?
Travel adjustment is possible but requires internal air spring modifications. It’s recommended to have a professional mechanic handle such changes.

4. What’s the correct sag for eMTB use with this fork?
Aim for 15–20% sag based on your total system weight. This provides a balance between traction and support, especially for heavier eMTB setups.

5. Why is my fork leaking oil?
Oil leakage usually points to worn dust wipers or overfilled bath oil. Replacing seals and correcting oil volume often resolves this.

6. Is the Float 40 Factory suitable for non-eMTB bikes?
While designed for eMTBs, it can be used on DH bikes with compatible frames and headsets. Its stiffness and weight are overkill for lighter trail bikes.

Conclusion

The Float 40 Factory eMTB fork from Fox is a finely engineered component that rewards meticulous care. Regular maintenance, timely service, and thoughtful setup allow you to extract maximum performance and reliability from this advanced suspension system. Whether you’re bombing downhill courses or riding rugged eMTB trails, this fork offers a pro-level experience when treated with expert care.