The RockShox SID SL Ultimate 3P is a performance-focused cross-country suspension fork designed for riders who demand precision, low weight, and tunability. It features a three-position damper (Open, Pedal, Lock) and Race Day 2 Charger damper technology to deliver optimal performance on varying terrain. This guide walks you through everything from installation and adjustment to troubleshooting and long-term maintenance to keep your fork functioning at its best.
Tools Required
- 5mm and 2mm hex wrenches
- Torque wrench [paid link] (2–10 Nm range)
- Suspension pump with a precise pressure gauge
- RockShox Maxima Plush damping fluid
- Isopropyl alcohol and clean rags
- Suspension grease (RockShox PM600 or SRAM Butter)
- Lower leg removal tool (compatible with SID SL)
- Replacement crush washers and foam rings (as needed)
- Shock oil measuring syringe or graduated beaker
Initial Setup and Installation
The SID SL Ultimate 3P is designed for cross-country race bikes with 100mm of travel and a lightweight chassis. Begin by confirming the fork’s specifications match your bike’s frame and headset standards, especially steerer tube type and axle spacing (15x110mm Boost).
Before installation, trim the steerer tube to match your bike’s head tube length. Always use a cutting guide to ensure a square cut and finish with a star nut installation if not using a threaded insert system. Torque all crown bolts and stem interfaces to manufacturer-recommended values, typically 5–6 Nm.
Install the front brake caliper and ensure rotor clearance through the fork arch. Confirm rotor size compatibility; the fork supports up to 180mm rotors without adapters. Ensure the axle threads smoothly and securely using RockShox’s recommended torque of 9–11 Nm.
Suspension Sag and Air Pressure Adjustment
Setting sag is critical to optimal fork performance. The SID SL Ultimate 3P uses a single positive air spring with an internally self-equalizing negative chamber.
- Wear your riding gear and sit on the bike in your normal position.
- Use the suspension pump to adjust the air pressure in small increments.
- The recommended sag for cross-country riding is approximately 15–20% of total travel (15–20mm for a 100mm fork).
- Check sag with the o-ring on the stanchion and fine-tune as needed.
Refer to RockShox’s air pressure chart for baseline pressure settings by rider weight. Always equalize the chambers by cycling the fork a few times after each adjustment.
Adjusting the 3P Compression Damper
The three-position compression damper includes Open, Pedal, and Lock settings:
- Open: For technical descents or rough terrain. Allows full oil flow and plush fork action.
- Pedal: Firms up low-speed compression to reduce bob while maintaining traction.
- Lock: Near-complete lockout for smooth climbs or sprinting.
Use the handlebar remote or top cap lever to switch between modes. Ensure cables are properly routed to avoid kinks or sharp bends that could affect performance.
Rebound Tuning
The red rebound adjuster is located at the bottom of the right fork leg. Start by setting rebound at the middle of its range and adjust based on your riding style:
- Faster rebound for smoother terrain or lighter riders.
- Slower rebound for aggressive riding or heavier riders.
Count the number of clicks from fully closed to fully open to track your settings easily.
Routine Maintenance Intervals
To keep the SID SL Ultimate 3P performing optimally, follow this maintenance schedule:
- Every 25 hours: Clean dust seals, inspect for oil residue, and apply lubrication. Check air pressure and adjust sag.
- Every 50 hours: Perform lower leg service. Replace oil, foam rings, and crush washers. Inspect stanchions for wear or scratches.
- Every 100 hours or annually: Full damper service including fluid change in the Charger Race Day 2 damper. This may require sending to a service center if you lack the proper vacuum bleeder tools.
Always use RockShox-approved fluids and service kits for compatibility and safety.
Lower Leg Service Procedure
This essential service removes contaminants and ensures smooth movement. Here are the key steps:
- Remove the air pressure and unscrew the rebound and air spring bolts.
- Gently tap bolts with a rubber mallet to disengage the legs.
- Slide off the lower legs and drain old oil.
- Replace foam rings and clean inside surfaces.
- Reassemble with fresh oil (15wt in bath), torque bolts properly, and test travel.
Check for bushing wear and seal integrity during this process.
Troubleshooting Common Set-Up Issues
Harsh initial stroke: Often caused by low air pressure or excessive compression damping. Recheck air pressure and damper position.
Fork won’t lock out: May be due to a damaged cable or internal fluid migration. Inspect remote actuation or perform a damper bleed.
Sticky movement or slow return: Caused by dry foam rings or contaminated oil. Perform a lower leg service.
Clicking noise: Often from dry bushings or a loose headset. Lubricate and retorque all fasteners.
Customization and Performance Tuning
For racers and advanced riders, tuning options include:
- Token adjustment: Add Bottomless Tokens to increase progression. Ideal for aggressive descents or heavier riders.
- Oil weight: Slight variations in damper oil viscosity can fine-tune compression and rebound feel.
- Remote upgrade: Switch to RockShox TwistLoc or AXS wireless system for cleaner cockpit and faster access.
Make incremental changes and test thoroughly before racing or long rides.
Compatibility Considerations
The SID SL Ultimate 3P is designed to be paired with lightweight cross-country drivetrains such as SRAM XX SL and Shimano XTR. Ensure brake mounts match your caliper model, and rotor size is compatible with the arch clearance.
The 15x110mm axle is Boost standard, so your hub must match. The fork is not compatible with traditional QR or non-Boost hubs.
Avoid mixing with forks from different series without matching axle-to-crown height, which affects bike geometry and handling.
Comparison with Similar RockShox Forks
| Model | Travel | Weight (Approx.) | Damper | Target Use |
|---|---|---|---|---|
| SID SL Ultimate 3P | 100mm | ~1326g | Charger Race Day 2 3P | XC Racing |
| SID Ultimate (non-SL) | 110–120mm | ~1480g | Charger 2.1 | Light Trail / XC |
| SID Select | 100–120mm | ~1600g | Charger RL | Budget XC |
The SL version sacrifices some adjustability and stiffness for weight savings, ideal for competitive racers.
Frequently Asked Questions (FAQs)
Q1: How often should I service the SID SL Ultimate 3P fork?
You should perform basic maintenance every 25–50 hours and a full damper service every 100 hours or annually.
Q2: Can I increase the travel of my SID SL Ultimate 3P?
No. This fork is limited to 100mm travel due to its chassis design and air shaft length.
Q3: Why does my fork feel harsh even after setting sag correctly?
Check rebound and compression damping settings. Also inspect for dry seals or internal contamination.
Q4: What kind of remote works with the 3P damper?
RockShox TwistLoc or OneLoc remotes are compatible. Ensure cable tension is correct during setup.
Q5: Is the SID SL Ultimate 3P compatible with flat-mount brakes?
No. It only supports post-mount calipers, with rotor sizes up to 180mm.
Q6: Can I perform lower leg service at home without special tools?
Yes, but you will need basic tools like a torque wrench [paid link], oil syringe, and seal kit. A service manual or video guide is helpful.
Conclusion
Maintaining your RockShox SID SL Ultimate 3P fork at home ensures consistent performance and longevity. With regular servicing, correct setup, and occasional customization, this fork delivers elite-level suspension tailored for cross-country racing. By following these instructions, you can confidently handle routine maintenance and maximize your bike’s front-end performance.