The Fox Float 36 Rhythm eMTB suspension fork is a performance-focused model designed specifically for the demands of electric mountain bikes. Built with Fox’s GRIP damper technology, it offers solid reliability, progressive performance, and eMTB-specific reinforcement. Servicing this fork correctly ensures consistent damping, longer component life, and improved rider control over varied terrain. This guide provides detailed insights into installation, adjustment, regular maintenance, troubleshooting, customization, and component compatibility—specific to the Float 36 Rhythm eMTB.
Tools Required
- 6 mm and 5 mm hex wrenches
- Torque wrench [paid link] with Nm scale
- Clean rags and isopropyl alcohol
- Suspension-specific grease
- Suspension oil (20wt Gold and 5wt T)
- Shock pump
- Seal driver and fork-specific bushing press tool
- Pick or seal removal tool
- Oil pan and nitrile gloves
Correct Installation of the Float 36 Rhythm eMTB
Proper installation begins with understanding the steerer tube dimensions and axle standards. The Float 36 Rhythm uses a 1.5″ tapered steerer and a 15×110 mm Boost axle.
Start by trimming the steerer to fit your bike frame and headset stack height, ensuring at least 30 mm of engagement with the stem. Torque the stem bolts to the manufacturer’s spec, typically 5-6 Nm.
For the axle installation, always ensure the dropouts and axle are clean and torque the Kabolt or QR15 axle bolt to 10 Nm. Improper torque can compromise fork alignment or cause creaking.
Air Spring Setup and SAG Adjustment
Correct air pressure is vital for the Rhythm’s performance. Use Fox’s recommended air pressure chart based on rider weight. Connect a shock pump to the top of the left leg and set your base pressure.
To measure SAG, wear full riding gear and mount the bike gently. Bounce once to settle the fork and slide the O-ring down to the seal. Dismount and measure the travel. The desired SAG is 15–20% of the fork’s travel—18–24 mm for a 160 mm fork.
Adjust the pressure incrementally in 5 psi steps to fine-tune SAG. Record your final settings for future reference.
GRIP Damper Adjustment Techniques
The GRIP damper offers compression adjustment via a top-mounted dial on the right leg. This dial modifies low-speed compression and has 10–11 distinct clicks.
Set rebound via the red knob under the fork leg. This controls how fast the fork returns after compressing. Start with the middle setting, then fine-tune based on trail conditions: slower for rough descents, faster for smooth terrain.
The GRIP damper is self-bleeding, so there’s no bladder to maintain. However, smooth adjustment and consistent feel are signs of a healthy damper.
Routine Maintenance Schedule
Regular maintenance extends the life of the Float 36 Rhythm. Lower leg service should be done every 30 riding hours or at least every 3 months. This includes cleaning the stanchions, replacing oil bath fluid, and inspecting wipers.
Damper and air spring full service is recommended every 100–125 hours. For eMTBs, which generally endure more torque and stress, consider reducing that interval to 80–100 hours.
Ensure all seals are cleaned and lubricated with suspension grease. Refill 20cc of 20wt Gold oil in each lower leg during reassembly.
Lower Leg Service Procedure
- Remove the front wheel and disc brake caliper.
- Loosen and remove the foot nut bolts using a 10 mm socket.
- Carefully slide off the lower legs while collecting any oil that drains.
- Remove foam rings and clean thoroughly.
- Reinstall new foam rings soaked in suspension oil.
- Slide lowers back onto the stanchions carefully without damaging wiper seals.
- Torque the foot nuts to 5.1 Nm and reinstall axle and brake caliper.
Always test the fork off the bike for smooth action before remounting.
Common Troubleshooting Issues
Fork feels sticky or slow to return: This usually points to contaminated or degraded oil, dry wipers, or insufficient air pressure.
Excessive dive under braking: Increase low-speed compression slightly and verify air spring pressure for proper support.
Creaking at the crown or steerer: Could indicate a loose headset or crown steerer unit (CSU) issue. Check headset torque, and if persistent, consult Fox for CSU inspection.
Oil leaking from seals: Indicates worn wiper seals or overfilled lowers. Perform a lower leg service and ensure correct oil volume.
Customization and Performance Tuning
You can tailor the Float 36 Rhythm’s ride with volume spacers inside the air spring. Adding spacers increases progression, making the fork firmer in the latter part of its travel.
The Rhythm can accept up to 5 spacers depending on fork travel. Use a 6 mm hex to remove the air cap, depressurize, and install the spacers on the air shaft top cap.
Adjust rebound and compression dials to match rider preference. Fast rebound suits flow trails; slower rebound enhances control in rock gardens.
Upgrade Considerations and Aftermarket Compatibility
Though the Rhythm uses a simplified GRIP damper, it’s compatible with Fox’s GRIP2 damper upgrade kits. These offer high/low-speed compression and rebound for riders seeking maximum tunability.
Volume spacers, oil seals, and air shaft assemblies are compatible across the Fox 36 range, simplifying part sourcing. However, always verify compatibility by fork model year.
Comparing Float 36 Rhythm with Fox Performance and Factory Forks
The Rhythm version differs from Performance and Factory models primarily in construction. It uses a heavier, one-piece magnesium lower leg, lacks the Kashima coating, and features the GRIP damper instead of FIT4 or GRIP2.
Factory forks offer advanced tuning and smoother action but at higher cost. For eMTB use, the Rhythm offers sufficient stiffness and durability at a better value, especially for aggressive trail and enduro use.
Float 36 Rhythm’s Compatibility with Drivetrain and Brakes
The Rhythm fork uses Boost spacing, which is compatible with modern 29” and 27.5” eMTB wheels. The 180 mm post mount disc brake tab supports rotors from 180 mm up to 203 mm with adapters.
It supports standard 15 mm thru-axles and is compatible with all current 1x drivetrains. Brake hose routing and fender mounting are integrated, ensuring clean cockpit setup.
FAQs
1. How often should I service the Float 36 Rhythm eMTB fork?
Every 30 hours for lower leg service, and every 80–100 hours for full air spring and damper service in eMTB applications.
2. Can I upgrade my GRIP damper to a GRIP2?
Yes, GRIP2 upgrade kits are available and compatible with the Float 36 Rhythm for riders seeking advanced tuning.
3. Why does my fork feel harsh over small bumps?
Check air pressure and rebound settings. Also, inspect seals and foam rings for dryness or contamination.
4. Are volume spacers included with the fork?
Typically, 1–2 spacers are pre-installed. Additional spacers can be purchased and installed for a more progressive feel.
5. What oil do I need for lower leg service?
Use 20wt Gold for bath oil and 5wt T for damper service, as specified by Fox.
6. Can I use a 27.5” wheel with the Float 36 Rhythm designed for 29”?
Yes, but only if the axle-to-crown measurement and offset match your frame geometry expectations. Always confirm clearance and geometry effects.