Top Features of the 38 Rhythm Suspension Fork

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The Fox 38 Rhythm is a performance-oriented suspension fork built to meet the needs of aggressive trail and enduro riders. As part of the Fox 38 series, the Rhythm variant is positioned as a cost-effective alternative that still delivers impressive performance, stiffness, and adjustability. This guide explores the installation, tuning, maintenance, troubleshooting, compatibility, and comparative advantages of the Fox 38 Rhythm suspension fork in detail.

Tools Required

  • Torque wrench [paid link] with 4mm, 5mm, and 6mm hex bits
  • Crown race setter
  • Star nut setter or compression plug tool
  • Suspension pump (high pressure)
  • Grease and assembly compound
  • Caliper alignment tool (optional)
  • Shock oil and seal kit (for maintenance)

Installation Guidelines for the Fox 38 Rhythm

Proper installation ensures optimal performance and longevity of the Fox 38 Rhythm fork. Begin by verifying steerer tube length and ensure compatibility with your frame’s head tube.

Start with cutting the steerer tube to fit your headset stack height and stem. Install the star nut or a threaded insert compression plug depending on whether you’re using an aluminum or carbon steerer. Apply assembly compound to the steerer and press in the crown race. Mount the fork into the head tube, install spacers and stem, and torque the top cap and stem bolts to spec.

Install the front wheel with a 15QR or 20QR axle depending on your fork model. Ensure the axle is fully seated and tightened. Finally, attach the front brake caliper using the correct adapter and align it properly with the rotor.

Adjustment and Tuning Options

The 38 Rhythm is built with the GRIP damper, which offers user-friendly performance tuning for a wide range of riders.

Air Spring Pressure

The fork uses Fox’s EVOL air spring, which features a large negative air chamber for better small-bump compliance. Set the air pressure according to your rider weight, referencing Fox’s recommended chart. Use a high-pressure suspension pump and adjust incrementally.

Rebound Damping

At the base of the right fork leg, a red knob allows you to fine-tune the rebound. Turning it clockwise slows rebound, ideal for high-speed descents. Counterclockwise quickens rebound, beneficial on flatter terrain.

Compression Damping

The blue dial atop the GRIP damper adjusts low-speed compression. Riders can fine-tune this for pedaling efficiency or plushness. The sweep-style adjuster allows precise, on-the-fly settings.

Routine Maintenance Best Practices

To maintain peak performance and prolong component life, follow a strict maintenance schedule for the Fox 38 Rhythm.

  • After every ride: Wipe down stanchions and seals with a clean cloth. Inspect for dirt accumulation and visible oil leakage.
  • Every 30 hours: Perform a lower leg service. Remove the lowers, clean internal components, replace foam rings, and refill with fresh bath oil.
  • Every 100 hours: Replace seals, inspect bushings, and do a full damper bleed if necessary.
  • Annually or every 200 hours: Perform a complete teardown including air spring, damper, and lower service.

Using genuine Fox seal kits and suspension fluids ensures compatibility and reliability.

Troubleshooting Common Set-up Issues

Some users may encounter initial challenges setting up their Fox 38 Rhythm. Below are common problems and their solutions.

Fork Not Returning Fully

This is usually caused by too much rebound damping or low air pressure. Adjust rebound for a faster return and re-check air pressure based on rider weight.

Harsh Top-Out or Bottom-Out

A harsh top-out often indicates insufficient negative air pressure or inadequate sag. For bottom-outs, consider increasing air pressure or adding volume spacers.

Brake Rub

Brake rotor misalignment is common. Ensure the caliper is torqued evenly and centered over the rotor. Using a caliper alignment tool can expedite this process.

Customization and Performance Optimization

For riders seeking fine-tuned performance, the 38 Rhythm offers several upgrade paths.

  • Volume Spacers: Adding tokens inside the air spring increases progression, preventing harsh bottom-outs during aggressive riding.
  • Aftermarket Decals: Customize aesthetics with Fox or third-party decal kits designed for the 38 platform.
  • GRIP2 Damper Upgrade: Though stock with GRIP, some riders opt to upgrade to the GRIP2 damper for high/low speed compression and rebound tuning.

Compatibility With Other Drivetrain Components

The Fox 38 Rhythm is compatible with most modern drivetrains and brake systems.

  • Brake Mounting: It features a 180mm direct post mount and supports up to 203mm rotors with the appropriate adapters.
  • Hub Standards: Available in 15x110mm Boost or 20x110mm Boost options, ensure hub spacing matches your fork.
  • Tire Clearance: Supports up to 2.6” tires on 29” and 27.5” wheels. Check clearance if using fenders or mudguards.

Ensure your headset and crown race are compatible with the fork’s tapered steerer tube (1.5” to 1-1/8”).

Comparison With Other Fox 38 Models

The 38 Rhythm differs from other Fox 38 variants like the Performance Elite and Factory in several areas.

  • Chassis: Shared 38mm stanchions offer stiffness across models. However, Rhythm uses a heavier chassis with fewer machining details.
  • Damper: GRIP damper on the Rhythm model is simpler than GRIP2 on Factory and Elite versions.
  • Stanchion Finish: The Rhythm uses black anodized stanchions, while higher-end models feature the Kashima coating for reduced friction.
  • Weight: Rhythm forks are slightly heavier due to fewer weight-saving materials.

These differences make the 38 Rhythm a solid choice for riders who prioritize value and durability without needing advanced damper controls.

Frequently Asked Questions

1. What is the maximum rotor size supported by the Fox 38 Rhythm?
The fork supports up to a 230mm rotor when using the correct adapter, ideal for aggressive descending and eMTB use.

2. Can I upgrade the damper on my 38 Rhythm to GRIP2?
Yes, the chassis is compatible with the GRIP2 damper, though professional installation is recommended due to damper press-fit requirements.

3. What volume spacers are compatible with the 38 Rhythm?
Fox air volume spacers specific to the 38mm chassis are compatible. The number and size will depend on rider preference and fork travel.

4. How much travel does the 38 Rhythm offer?
It is available in travel options from 160mm to 180mm, depending on the wheel size and model.

5. Does the 38 Rhythm come with a fender mount?
Yes, it features integrated fender mounts compatible with the Fox 38 bolt-on fender.

6. What’s the weight difference between the 38 Rhythm and the Factory model?
The Rhythm is approximately 200–300 grams heavier due to the simpler chassis and damper.

Conclusion

The Fox 38 Rhythm delivers premium performance in a cost-efficient package, offering the stiffness and travel needed for hard-charging enduro and aggressive trail riding. While it lacks some of the refinements of the higher-end Factory and Performance Elite models, its robust construction, dependable GRIP damper, and user-friendly setup make it a highly recommended choice for riders prioritizing value and reliability. By following proper setup and maintenance practices, the 38 Rhythm can serve as a durable and high-performing component on any serious mountain bike.