The Fox Float 40 Factory eMTB fork represents one of the highest tiers in suspension technology specifically designed for electric mountain bikes. Known for its strength, adjustability, and performance under demanding conditions, this fork is often considered a professional-grade upgrade. In this comprehensive guide, we’ll examine its installation, fine-tuning, maintenance, and performance optimization. We’ll also troubleshoot common issues, analyze its compatibility with other components, and compare it with similar forks to determine if it’s truly worth the investment.
Tools Required
- 6mm and 8mm Allen keys [paid link]
- Torque wrench [paid link]
- Suspension pump
- Shock oil (if servicing internally)
- Isopropyl alcohol and clean rags
- Crown race setting tool
- Star nut setter
- Torque specifications sheet from Fox
Installation Guide for Float 40 Factory eMTB
Installing the Float 40 Factory eMTB requires precision due to its high-performance build and specific eMTB compatibility. Begin by checking the steerer tube length and cutting it to match your frame if necessary. Install the crown race and press the fork into the headtube, ensuring proper headset compression. Use a torque wrench [paid link] to secure the stem bolts evenly, avoiding over-tightening.
Because this fork is a dual-crown design, ensure that the upper and lower crowns are aligned accurately. Misalignment can lead to premature wear or steering issues. Use the manufacturer’s recommended torque settings when securing the crowns and stem. Finally, install the front wheel and brake calipers, making sure that rotor clearance and alignment are perfect.
Adjusting the Float 40 Factory for Maximum Performance
The Float 40 Factory is equipped with a wide array of adjustability features, including:
- High- and low-speed compression damping
- High- and low-speed rebound damping
- Air spring pressure
Begin with Fox’s recommended baseline settings for rider weight, then fine-tune from there. Use a suspension pump to set the correct air spring pressure based on rider weight. Adjust compression and rebound settings incrementally during test rides to find your ideal feel. Low-speed compression affects pedaling support and cornering, while high-speed compression controls how the fork reacts to fast hits and landings.
Dial in rebound settings to ensure the fork returns smoothly without “bouncing.” A too-fast rebound can cause instability, while a too-slow rebound may feel sluggish over successive impacts. Ensure balance with the rear shock for a harmonious ride feel.
Routine Maintenance and Long-Term Care
Maintaining the Float 40 Factory fork is essential for prolonging performance and avoiding costly rebuilds. Follow these intervals:
- Every 25 hours: Wipe down stanchions, inspect seals, and lubricate with a light suspension oil.
- Every 50 hours: Change lower leg oil, inspect bushings and seals for wear.
- Every 100-125 hours: Perform a full damper and air spring service.
Use only Fox-recommended fluids and parts. Contamination from using generic oils or improper assembly can severely affect performance. Keep the fork clean after every ride, especially in muddy or wet conditions, to prevent grit from damaging seals.
Troubleshooting Common Issues
Several common problems can arise with improper setup or wear:
- Fork feels harsh or locks out prematurely: Likely caused by too much high-speed compression. Reduce compression and test again.
- Fork dives excessively under braking: May indicate low air pressure or insufficient low-speed compression.
- Noisy rebound or “clunking”: Often a symptom of too little rebound damping or internal wear; inspect or service accordingly.
- Oil leaking from the seals: Indicates worn or damaged wiper seals. Replace them promptly to avoid contamination.
Always ensure torque specs are met during adjustments. Incorrect torque can lead to creaking, misalignment, or even structural damage over time.
Customizing and Tuning the Float 40 Factory for Rider Preferences
This fork offers high customization potential. Riders can install volume spacers to change the progression curve of the air spring. Fewer spacers yield a more linear feel, while more spacers increase bottom-out resistance. Additionally, adjusting fork height with crown spacers can slightly alter head angle and bike handling characteristics.
Riders participating in gravity events may prefer slower rebound and increased compression. Trail riders may opt for more active suspension with lighter settings. Using telemetry tools or ride logs can help refine settings over time based on terrain and ride style.
Compatibility with Other Drivetrain and Suspension Components
The Float 40 Factory eMTB is compatible with most eMTB frames that accommodate dual-crown forks. It’s designed to handle the increased weight and torque loads from electric drivetrains. Ensure your frame’s headtube can accept a dual-crown fork—this model requires specific geometry and clearance.
It pairs best with high-performance rear shocks such as the Fox DHX2 or Float X2. Using this fork with underpowered or mismatched rear suspension can lead to imbalanced ride characteristics. Brake mount compatibility is post-mount 203mm; adapters may be required for other rotor sizes.
Performance Comparison: Float 40 Factory vs. Other High-End Forks
Comparing the Float 40 Factory eMTB to similar models reveals several advantages:
- Vs. RockShox Boxxer Ultimate: The Float 40 has more adjustability options and a more refined chassis stiffness profile, though the Boxxer is slightly lighter.
- Vs. Öhlins DH38 m.1: Öhlins offers buttery small-bump compliance but less high-speed adjustment flexibility. The Float 40 caters better to riders who prefer extensive tuning.
- Vs. Fox 38 Factory: The 38 is lighter and better for aggressive trail/enduro, but the 40 Factory shines on dedicated eMTB downhill and park terrain.
These comparisons highlight the Float 40 Factory’s niche as a full-commitment fork for aggressive eMTB applications.
Final Verdict: Is the Float 40 Factory eMTB Worth It?
For riders who demand top-tier suspension performance from their eMTBs, the Float 40 Factory is undeniably worth it. Its premium build, extensive tuning options, and eMTB-specific durability make it ideal for downhill racers, bike park enthusiasts, and serious enduro riders. While it may be overkill for casual or trail use, it delivers unmatched control and confidence in technical terrain.
Its price point and complexity may be barriers for some, but for those who push the limits of what eMTBs can do, the investment returns in superior ride quality and long-term reliability.