The Fox Float 40 Factory eMTB suspension fork is a top-tier choice for riders who demand precise handling, high-end tunability, and long-term durability in aggressive terrain. Engineered specifically for electric mountain bikes (eMTBs), the Float 40 Factory offers a tailored experience that balances power, control, and confidence on steep descents and technical trails. This guide explores everything from installation to performance optimization.
Tools Required
- Torque wrench [paid link] (with Nm range appropriate for fork bolts)
- Allen key set (2mm to 8mm)
- Suspension pump
- Crown race setting tool
- Grease and carbon paste
- Torque spec chart (Fox-specific)
- Caliper alignment tool (optional)
Installation Procedure
The installation of the Float 40 Factory eMTB fork requires attention to detail and the right tools. Begin by ensuring your frame and headset are clean and compatible. This model uses a standard 1.5” tapered steerer tube, making it suitable for most modern eMTB frames.
After cutting the steerer to the correct length, install the star nut or compatible compression plug if using a carbon steerer. Grease the crown race before seating it. Slide the fork into the head tube, stack your spacers, stem, and top cap, then torque to manufacturer specifications.
Finally, attach the brake caliper to the fork’s post mount and install the front wheel, ensuring the 20mm thru-axle is torqued properly.
Initial Adjustment Settings
Proper tuning is essential for peak performance. The Float 40 Factory uses an EVOL air spring and GRIP2 damper, both of which offer wide adjustability:
Air Pressure (EVOL Air Spring):
Set the sag between 15–20% for downhill riding. Use a shock pump and measure sag while in full riding gear.
Rebound:
Adjust the red dial at the bottom of the right leg. Start at the middle setting, then fine-tune based on terrain and riding style.
Compression (GRIP2):
Use the high- and low-speed compression dials on the right leg’s crown. Start at baseline settings provided by Fox and adjust after test rides.
Routine Maintenance
To maintain consistent performance, regular maintenance is necessary:
- Every 30 hours: Clean and inspect the stanchions, wipers, and lower legs. Re-lube the dust wipers.
- Every 100 hours: Perform a full lower leg service. Replace oil and clean damper internals.
- Annually: Conduct a damper and air spring overhaul.
Always use Fox-approved fluids and follow their service intervals closely.
Common Set-Up Issues and Troubleshooting
Fork Feels Harsh or Doesn’t Use Full Travel
Check sag and air pressure. Over-inflation is the most common cause. Also inspect the volume spacers; too many will restrict travel.
Excessive Brake Dive
Increase low-speed compression damping. Re-check fork alignment and headset torque to rule out mechanical issues.
Poor Small Bump Compliance
Reduce high-speed compression. Ensure stanchions and seals are clean and properly lubricated.
Clicking or Popping Sounds
Could indicate dry bushings or loose thru-axle. Inspect lower legs for contamination or torque discrepancies.
Customization and Performance Optimization
The Float 40 Factory eMTB allows extensive customization. Riders can modify the air spring curve using volume spacers. Reducing spacers offers a more linear feel; adding them gives more bottom-out resistance.
For tuning the GRIP2 damper:
- Increase high-speed compression for bigger hits.
- Adjust low-speed compression for cornering support.
- Modify high-speed rebound for landing stability.
- Fine-tune low-speed rebound for better tracking.
These micro-adjustments enable a personalized ride feel, maximizing confidence on challenging terrain.
Model Comparisons
Compared to the Fox 38 Factory, the Float 40 offers a stiffer chassis with 40mm stanchions versus the 38mm, resulting in enhanced steering precision. While the 38 excels in enduro, the 40 Factory is unmatched in steep, downhill-focused terrain due to its dual-crown design and extended travel range.
Versus the RockShox BoXXer Ultimate, the Float 40 Factory provides better small bump sensitivity and a broader adjustment range thanks to the GRIP2 damper.
Compatibility with Other Drivetrain and Chassis Components
The Float 40 Factory eMTB is compatible with most modern eMTB frames, provided they accept dual crown forks. It pairs well with frames that offer 200mm rear travel, and is designed to work seamlessly with 20x110mm Boost front hubs.
Brake compatibility includes 203mm and 220mm rotors with direct mount options. The axle standard supports e-bike-rated thru-axles, ensuring stiffness and reliability under load.
Tire clearance is ample, accommodating up to 29×2.6” tires. This allows riders to match their tire selection to terrain conditions without compromising fork performance.
FAQs
Q1: Can I use the Float 40 Factory on a non-eMTB frame?
Yes, but it’s optimized for the weight and load of eMTBs. On lighter frames, handling may feel overly stiff.
Q2: How often should I change the suspension oil?
Fox recommends a lower leg service every 100 hours, which includes oil replacement.
Q3: What’s the travel range of the Float 40 Factory?
It comes factory-tuned for 203mm of travel and is not internally adjustable like some other models.
Q4: Is the GRIP2 damper difficult to tune for beginners?
The damper has a learning curve, but Fox provides baseline settings. Beginners can start from these and adjust incrementally.
Q5: Do I need special tools to install this fork?
Basic shop tools suffice, but a crown race setting tool and torque wrench [paid link] are strongly recommended.
Q6: Can I retrofit the Float 40 with a coil spring?
No, this model is strictly air-sprung and not compatible with Fox’s coil spring kits.
Conclusion
The Fox Float 40 Factory eMTB suspension fork is a premier choice for riders seeking exceptional downhill control, adjustability, and compatibility with high-performance eMTBs. With its GRIP2 damper, EVOL air spring, and robust construction, it meets the demands of aggressive trail riders and racers alike. Regular maintenance and thoughtful tuning will ensure this fork delivers consistent performance across seasons and terrain.