The Float 40 Factory eMTB by Fox is a purpose-built, high-performance suspension fork designed specifically for electric mountain bikes. Engineered with a focus on stiffness, durability, and tunability, this model sits at the pinnacle of Fox’s 40 series and offers numerous features that make it an attractive option for aggressive riders. In this guide, we’ll delve into every aspect of the Float 40 Factory eMTB, including its installation, adjustment, and maintenance procedures, as well as how to optimize it for top-tier performance.
Tools Required:
- Torque wrench [paid link] with appropriate hex and Torx bits
- Suspension pump
- Fox Float fluid and grease
- Allen wrenches [paid link] (4mm, 5mm, 6mm)
- Clean rags and isopropyl alcohol
- Suspension service kit (Fox-specific)
- Crown race setting tool
Installation Process
The Float 40 Factory eMTB is a dual-crown suspension fork, which requires specific frame and headset compatibility. Begin by ensuring the head tube of your eMTB supports a dual-crown setup with a tapered steerer.
Steerer Preparation:
Cut the steerer to fit your frame’s stack height. Always measure twice before cutting to avoid a short steerer. Install the star nut or a suitable headset insert if using a carbon steerer.
Crown Race and Headset Interface:
Install the crown race using a proper crown race setting tool. Grease the headset bearings and install the fork into the head tube. Tighten the stem and top cap bolts according to manufacturer torque specifications.
Brake and Wheel Installation:
Mount a compatible 203mm or 220mm disc brake rotor. Attach the caliper and center it over the rotor. Install the front wheel and torque the axle correctly. Use a torque wrench [paid link] to secure pinch bolts on the lowers.
Adjustment Procedures
Fox provides several tuning options with the Float 40 Factory eMTB, including air pressure, rebound, and compression damping.
Air Spring Setup
Start with the recommended air pressure based on your rider weight, listed in the Fox setup guide. Use a suspension pump to dial in the pressure. Adjust sag by wearing your full riding kit and measuring the percentage of travel used while in the attack position—target 15-20%.
High and Low-Speed Compression
Use the blue dials atop the right fork leg to fine-tune both high and low-speed compression. Low-speed compression affects pedal bob and cornering, while high-speed helps absorb big hits and landings. Start with middle settings and adjust incrementally during test rides.
Rebound Damping
Located at the bottom of the fork leg, the red knob adjusts rebound. Begin with a middle setting and tweak to find your desired response—slower for more control or faster for a livelier feel.
Routine Maintenance
To maintain peak performance and longevity, follow Fox’s maintenance schedule.
After Every Ride
- Wipe down stanchions and dust seals with a clean cloth.
- Inspect for oil leakage or dirt buildup around the seals.
Every 30 Riding Hours
- Clean and inspect lowers.
- Apply Float fluid to the foam rings and dust seals.
Every 100 Riding Hours or Annually
- Perform a full lower leg service.
- Replace oil and inspect internal components.
- Grease the air spring assembly and inspect damper function.
Troubleshooting Common Set-Up Issues
Even with precise setup, problems can arise. Here are the most frequent ones and how to address them:
Excessive Fork Dive
Often caused by too little low-speed compression or too much sag. Increase low-speed compression and verify air pressure.
Harsh Bottom-Outs
Check for insufficient high-speed compression damping or inadequate air pressure. Re-check sag and increase pressure as needed.
Sticky or Unresponsive Travel
Dirty or dry seals can hinder performance. Clean stanchions, re-lubricate foam rings, and perform a lower leg service.
Customization and Optimization
The Float 40 Factory eMTB supports numerous customization avenues to tailor performance.
Air Volume Spacers
Changing volume spacers adjusts the spring curve. More spacers create a more progressive feel; fewer make it linear. Fine-tune based on riding terrain and style.
Kashima Coating Performance
This factory-exclusive feature reduces friction and improves responsiveness. Maintain the coating by cleaning after every ride and avoiding abrasive cleaners.
Grip2 Damper Adjustability
The standout feature is the GRIP2 damper, which allows independent high/low-speed damping adjustments. Ideal for enduro and downhill riding styles.
Compatibility with Other Drivetrain Components
The Float 40 Factory eMTB doesn’t interface directly with drivetrain components, but its axle and rotor standards must match your wheels and brakes. It uses:
- 110x20mm Boost thru-axle
- Post mount brake tabs (minimum 203mm rotor)
Ensure your wheel hub and brake caliper are compatible with these standards. While not directly affecting drivetrains, fork stiffness can influence the perception of pedaling efficiency on technical climbs.
Comparison with Similar Models
The Float 40 Factory eMTB stands out among its peers, particularly when compared with the RockShox BoXXer Ultimate and Manitou Dorado Pro.
Fox vs. RockShox BoXXer Ultimate
- Fox offers more adjustability with GRIP2, while RockShox uses the Charger 2.1 damper.
- The Kashima coating on the Fox fork reduces stiction more effectively.
- Fox provides better small bump sensitivity due to its EVOL air spring.
Fox vs. Manitou Dorado Pro
- Manitou uses a reverse arch design and a more linear air spring feel.
- Fox leads in damping customization and stiffness under load.
- Dorado is slightly lighter, but Fox provides a more robust eMTB-specific build.
FAQs
Q1: Is the Float 40 Factory eMTB suitable for all eMTB models?
No, it requires frames compatible with dual-crown forks and tapered head tubes.
Q2: How often should I service the Float 40 Factory eMTB fork?
Basic cleaning every ride, lower service every 30 hours, and full service every 100 hours or annually.
Q3: Can I install it on a non-eMTB downhill bike?
Yes, but the stiffer chassis is optimized for eMTB use and may feel overbuilt for lightweight non-motorized setups.
Q4: What are the benefits of the Kashima coating?
It reduces friction, enhances small bump compliance, and improves fork longevity.
Q5: Does this fork come with volume spacers pre-installed?
Yes, it includes a factory-set number, but users can add or remove them to customize spring progression.
Q6: Is it possible to upgrade from a lower-end Fox 40 model to the Factory version?
Upgrades are limited; the GRIP2 damper and Kashima coating are not retrofit-compatible.
Conclusion
The Fox Float 40 Factory eMTB is arguably the best suspension fork for demanding eMTB riders seeking maximum performance, stiffness, and adjustability. Its high-end features like the GRIP2 damper, Kashima coating, and robust chassis make it a standout choice. For riders pushing the limits on rough terrain, this fork offers unparalleled control and customization.