The Fox Float 36 Rhythm eMTB suspension fork is a purpose-built, performance-oriented component designed specifically for aggressive e-mountain biking. With its robust chassis and GRIP damper, the 36 Rhythm is built to withstand challenging trails while offering predictable performance. Regular inspection is crucial to maintain responsiveness and longevity. This detailed guide walks through installation verification, setup checks, inspection procedures, troubleshooting, and optimization tips tailored for the Float 36 Rhythm model.
Tools Required
- Torque wrench [paid link] with 4mm to 6mm hex bits
- Clean lint-free cloths
- Suspension pump
- Caliper or ruler
- Isopropyl alcohol (minimum 90%)
- Suspension oil (Fox 20wt Gold recommended)
- Suspension grease
- Small pick or soft plastic tool
- Workstand (optional but recommended)
Installation and Setup Verification
Proper installation is the foundation of effective performance. Before inspecting your Float 36 Rhythm, verify the fork was installed to Fox specifications. The steerer tube must be correctly cut and securely torqued inside the headset using appropriate spacers. Confirm the thru-axle is fully tightened to spec, ensuring the front wheel is centered without play. Check for any side-to-side looseness at the crown or stanchions, which may indicate improper torquing or bearing wear in the headset.
Ensure the brake caliper is aligned without rotor rub and that the disc rotor bolts are torqued to manufacturer specifications. In eMTBs, additional weight and torque demand a meticulous setup to avoid premature wear or safety issues.
Suspension Fork Inspection Procedure
External Visual Check
Begin with a dry, clean fork. Inspect the stanchions for scratches or nicks, which can tear wiper seals or lead to oil leakage. Examine the lower legs for dents, especially on the casting near the dropouts. Verify that all external bolts, such as brake mount and axle retention bolts, are tight and free from corrosion.
Next, examine the dust wipers for signs of oil weeping. A light film is normal, but visible drips or dirt-stained oil may indicate worn seals. Use a clean cloth to wipe the stanchions and observe any residue or damage.
Compression and Rebound Test
Push down firmly on the handlebars to compress the fork through its travel. The motion should be smooth and linear. Listen for any abnormal noises such as squelching, clicking, or knocking. Rebound should be consistent and controlled—rapid return or harsh top-out sounds may indicate damper or air spring issues.
Adjust the GRIP damper’s rebound and compression knobs and observe the changes. Lack of response when adjusting damping settings suggests internal contamination or wear.
Sag and Air Spring Check
Verify sag by using the fork’s rubber o-ring or a zip tie. Load the rider weight and measure sag percentage using the total travel (usually 160mm for the 36 Rhythm). Fox recommends 15-25% sag depending on riding style. Under-sag can cause harshness; over-sag leads to bottom-outs.
If sag is outside optimal range despite appropriate air pressure, inspect for air leaks using a suspension pump. A consistent drop in pressure signals air spring seal failure.
Troubleshooting Common Issues
Oil Leaks at Dust Wipers
Persistent oil weeping at the seals may be caused by damaged stanchions or contaminated oil. Begin by gently lifting the wiper seal using a plastic pick and cleaning the foam rings underneath. Re-lubricate with fresh oil. If leaks persist, a full lower leg service is required, including seal and oil replacement.
Inconsistent Rebound or Compression
This typically stems from air mixing with damper oil due to inadequate maintenance or factory defects. If the fork feels inconsistent during rebound or “dead” under compression, a damper bleed or complete rebuild is necessary.
Harshness in Small Bumps
This issue is often traced to dry foam rings or dirty wipers. Performing a lower leg clean and re-lube can restore small-bump compliance. Also, confirm that rebound isn’t set too fast, which can mimic stiffness.
Maintenance Schedule and Recommendations
Fox recommends performing a lower leg service every 30 hours of ride time and a full damper and air spring service every 100 hours. For eMTBs, consider shorter intervals due to increased fork stress. Regular inspections—monthly for frequent riders—help catch early signs of wear.
During lower leg service, remove the fork’s lowers, clean and replace the foam rings, and add fresh suspension oil. Clean all contact surfaces thoroughly before reassembly.
Customization and Performance Optimization
Although the Float 36 Rhythm uses the GRIP damper—considered less adjustable than GRIP2—there are still customization options. Air volume can be tuned using Fox volume spacers. Adding spacers increases progression and bottom-out resistance. Fox provides a chart for volume spacer configuration based on rider weight and style.
Rebound and compression damping, although not independently adjustable in multiple stages, can be fine-tuned to enhance control. Setting rebound to the midpoint and adjusting based on trail feedback is effective for most riders. Compression knob tuning helps maintain mid-stroke support on steeper descents.
Compatibility with Other Drivetrain Components
The Float 36 Rhythm is compatible with both Boost and standard front hubs depending on axle specifications. Brake mount spacing supports 180mm or larger rotors, critical for eMTBs that need strong braking systems.
This fork integrates seamlessly with most modern drivetrains and headsets but always confirm crown race diameter and steerer tube compatibility, especially when retrofitting into older frames.
Comparison with Similar Models
Compared to the Fox 36 Performance Elite or Factory series, the Rhythm version uses a simpler damper (GRIP instead of GRIP2) and heavier, more affordable castings. However, the core structure remains durable and trail-worthy. Riders prioritizing cost-effectiveness and reliability over adjustability will find the Rhythm ideal.
On the other hand, more aggressive or competitive riders may benefit from upgrading to the GRIP2 damper for finer control over high-speed compression and rebound. Still, the Rhythm holds its own in most trail and all-mountain conditions.
FAQs
How often should I inspect the Fox Float 36 Rhythm fork?
Perform a basic inspection monthly, or after every 10 hours of ride time, and follow Fox’s 30-hour lower leg service schedule for optimal performance.
What oil should I use for servicing the Float 36 Rhythm?
Fox recommends 20wt Gold suspension oil for the lower leg service. Always match Fox’s viscosity and quantity specifications.
Can I install the GRIP2 damper into a Float 36 Rhythm?
While technically possible, it involves significant cost and may void warranties. Consider upgrading the fork if advanced adjustability is needed.
Why is my fork not returning smoothly after compression?
This could be due to air spring seal wear or contamination in the rebound circuit. A service or damper bleed may resolve the issue.
What’s the correct sag setting for the Fox Float 36 Rhythm?
Ideal sag is between 15-25% of total travel, depending on rider preference and terrain. Use a suspension pump to adjust air pressure accordingly.
Can the Fox Float 36 Rhythm handle double-crown-level impacts?
While robust, it is still a single-crown fork and not designed for full downhill racing loads. Use within its intended trail or enduro discipline.
Conclusion
The Fox Float 36 Rhythm eMTB fork is a solid performer designed to deliver consistent, responsive suspension for electric mountain bikes. Regular inspection, correct sag setting, and timely service ensure it stays responsive on rugged terrain. While it lacks some high-end features, its durability and simplicity make it a dependable choice for most riders. For those seeking reliability without excessive maintenance complexity, the 36 Rhythm offers an excellent balance of performance and value.