The Fox Float 40 Factory eMTB suspension fork is engineered for high-performance electric mountain bikes, offering supreme stiffness, plush travel, and adjustability for aggressive downhill riding. To maintain its performance and ensure safety, regular inspection and service are critical. This comprehensive guide walks you through the detailed process of inspecting and maintaining your Float 40 Factory fork, troubleshooting common issues, and ensuring optimal setup for demanding trail conditions.
Tools Required
- Torque wrench [paid link] with appropriate sockets
- Shock pump (compatible with EVOL air spring)
- Suspension oil (Fox specified)
- Hex/Allen key set (2mm to 8mm)
- Clean rags and isopropyl alcohol
- Plastic tire levers
- Digital caliper [paid link] (optional, for precise measurements)
Understanding the Float 40 Factory eMTB Fork Design
The Float 40 Factory is a dual-crown, air-sprung fork specifically tuned for eMTBs. It features the FIT GRIP2 damper, EVOL air spring, and Kashima-coated stanchions. Its 40mm stanchions offer superior rigidity, while the damper allows for high and low-speed compression and rebound adjustments. Its design emphasizes control, support, and tunability for varied terrain and rider styles.
Pre-Ride Visual Inspection
Regular visual checks are the first step in identifying wear or damage before they affect performance.
Stanchion and Seal Condition
Inspect the stanchions for scratches, nicks, or oil residue. Any visible damage can compromise the fork’s performance and potentially damage internal seals. Also check the dust wipers for cracks or embedded debris, which could lead to oil contamination.
Arch and Lowers
Examine the fork arch for impact damage. Cracks or deformation can compromise structural integrity. Ensure the lowers are clean and that no oil is leaking from the bleed valves or casting interfaces.
Crown and Steerer Tube
Look for stress marks or play at the crown-steerer junction. This area endures high forces and should remain free from movement or creaking.
Functional Inspection
Once the fork passes a visual check, move on to a functional assessment to ensure all systems perform optimally.
Compression and Rebound
Cycle the fork through its travel while adjusting the high-speed and low-speed compression dials. There should be a noticeable change in firmness. Repeat the process with the rebound settings. If any adjustments have no effect or feel inconsistent, the damper may require servicing.
Air Spring Integrity
Deflate the fork and slowly compress it to listen for abnormal air leaks. Reinflate to the recommended pressure using a shock pump and check for pressure retention over time. A drop indicates possible air chamber seal failure.
Detailed Maintenance Procedures
Routine service keeps the Float 40 Factory operating as intended. Fox recommends a lower leg service every 30 hours and a full damper service every 100 hours.
Lower Leg Service
Remove the wheel, brake caliper, and axle. Using the correct hex keys [paid link], unbolt the lower legs. Drain the old oil and inspect the foam rings and seals. Replace worn components and refill with fresh Fox suspension oil as specified for the Float 40 Factory model. Reassemble and torque to specification.
Air Spring Service
Disassemble the air spring side of the fork to inspect the EVOL negative chamber seal head, shaft, and piston. Replace seals and lubricate with Fox Float Fluid. This ensures smooth travel and consistent air pressure.
Troubleshooting Common Set-Up Issues
Correctly identifying setup issues early prevents performance loss and costly repairs.
Harsh Bottoming or Spiking
If the fork bottoms out easily despite proper pressure, consider increasing high-speed compression damping or adding volume spacers. This adjusts the progression rate for better support at the end of the stroke.
Excessive Dive or Brake Jack
Excessive dive under braking may stem from low air pressure or insufficient low-speed compression damping. Recheck sag and increase damping as necessary.
Inconsistent Travel or Dead Stroke
If the fork exhibits a “dead zone” or inconsistent compression, inspect the air spring for trapped air or oil contamination. A full air spring rebuild is often required in such cases.
Optimization and Customization
The Float 40 Factory allows riders to tailor suspension feel to their weight, terrain, and riding style.
Volume Spacers
Adding or removing air volume spacers changes the spring curve. More spacers increase progression for aggressive terrain, while fewer enhance small bump sensitivity.
Damper Adjustments
Fine-tuning the GRIP2 damper can yield significant performance gains. Use Fox’s recommended base settings as a starting point and test incrementally.
Compatibility with eMTB Drivetrains and Frames
The Float 40 Factory is compatible with modern eMTB frames that accommodate dual crown forks and wide stanchions. Ensure adequate clearance at the head tube and downtube area. The fork’s axle spacing is Boost 20x110mm, and it fits 29-inch wheels with up to 2.6-inch tire clearance.
Comparing the Float 40 Factory to Similar Models
Float 40 Performance vs. Factory
The Factory model includes Kashima-coated stanchions and the GRIP2 damper, which offer superior tunability and small-bump compliance compared to the Performance model’s black anodized stanchions and simpler damper.
Fox 38 Factory vs. Float 40 Factory
While the Fox 38 is ideal for enduro eMTBs, the Float 40 excels in gravity and downhill eMTB applications. Its dual crown design offers enhanced stiffness and control, particularly during sustained high-speed descents.
Frequently Asked Questions (FAQs)
Q1. How often should I service my Float 40 Factory fork?
Lower leg service is recommended every 30 hours of riding, and full damper service at 100 hours for optimal performance.
Q2. What air pressure should I use for my weight?
Refer to Fox’s suspension setup guide for base pressures based on rider weight. Adjust from there to dial in sag and support.
Q3. Can I use the Float 40 Factory on a regular MTB?
It is not recommended due to its weight and design being optimized for eMTBs and downhill applications.
Q4. How do I know if my fork needs a rebuild?
Signs include oil leakage, inconsistent damping, loss of air pressure, or noise during travel.
Q5. Is the Kashima coating just cosmetic?
No. Kashima reduces friction and wear, improving performance and extending fork life.
Q6. Can I upgrade the damper in my Float 40 Factory fork?
The Factory model already includes the premium GRIP2 damper. Upgrades would typically be unnecessary unless replacing worn parts.
This guide provides a complete, technical overview for inspecting and maintaining the Fox Float 40 Factory eMTB fork. Regular servicing ensures consistent performance and helps extend the lifespan of your suspension under demanding trail conditions.