The SID SL Ultimate 2P by RockShox is a high-performance cross-country fork engineered for riders seeking precise control and ultralight responsiveness. This guide provides a detailed overview of its installation, adjustment, maintenance, and optimization. Whether you’re considering an upgrade or fine-tuning your setup, this article offers essential insights.
Tools Required
- Torque wrench [paid link]
- 2.5mm, 5mm, and 6mm hex wrenches
- Star nut setter or threaded insert tool (for carbon steerers)
- Suspension pump
- Digital caliper [paid link] (for measuring sag)
- Shock oil and seals (for lower leg service)
Installation Guide for SID SL Ultimate 2P
Installing the SID SL Ultimate 2P requires care and precision to ensure optimal performance. Begin by verifying the fork’s steerer tube length against your bike’s head tube and stem stack height. If necessary, trim the steerer using a pipe cutter and install the star nut or threaded insert.
The fork crown must sit flush with the headset bearing. Use a torque wrench [paid link] to secure the stem bolts to the manufacturer’s specifications, typically around 5–6 Nm. Attach the front brake caliper, ensuring it aligns correctly with the rotor. Finally, check that the thru-axle is properly torqued and the front wheel spins freely.
Suspension Adjustment and Tuning
Correct suspension setup is crucial to unlocking the performance of the SID SL Ultimate 2P. This model features the Charger Race Day 2 damper and DebonAir+ air spring, which work together to balance small-bump sensitivity and mid-stroke support.
Set sag to 15–20% of total travel, using a suspension pump to adjust air pressure. RockShox provides recommended pressure charts based on rider weight. After setting sag, dial in rebound using the red knob at the bottom of the right leg. Fast rebound recovers quickly after impacts but can cause instability, whereas slower rebound improves traction but can feel sluggish.
Compression adjustment is simplified with a 2-position remote or top cap dial—open and locked. This dual-position system is intuitive for race scenarios, enabling efficient power transfer on climbs and plush compliance on descents.
Routine Maintenance Practices
Regular maintenance preserves fork performance and extends its service life. Clean the fork stanchions after every ride to remove dirt that can degrade the seals. Every 50 hours of ride time, perform a lower leg service by removing the lowers, replacing the foam rings, seals, and oil.
Inspect the air spring and damper internals every 100–200 hours depending on riding conditions. Replace worn seals promptly to prevent contamination. Always use RockShox-approved lubricants and torque specifications.
Troubleshooting Common Set-Up Issues
Riders may encounter common setup issues with the SID SL Ultimate 2P. Excessive stiction typically results from dry foam rings or over-tightened crown bolts. Re-lubricating or replacing the foam rings and confirming correct torque can resolve this.
If the fork feels harsh or bottoms out too easily, revisit the air pressure and sag settings. A fork that tops out harshly on rebounds likely has rebound damping set too fast. For inconsistent lockout performance, inspect the remote cable tension and ensure the damper is properly bled.
Customization and Performance Optimization
To tailor the SID SL Ultimate 2P to your riding style, consider adding volume spacers to adjust the air spring curve. More spacers create a more progressive feel—ideal for aggressive riders—while fewer provide a linear, plush ride.
The fork is compatible with both remote and crown adjust lockouts. Riders focusing on weight savings may prefer the crown version. Adjusting axle-to-crown height and offset using different lower leg assemblies can also fine-tune handling characteristics for specific courses.
Compatibility with Other Drivetrain and Frame Components
The SID SL Ultimate 2P is designed for 100mm travel and 29” wheels, with a Boost hub spacing of 15x110mm. It pairs best with XC race frames featuring tapered head tubes and short chainstays. It is fully compatible with both flat-mount and post-mount brakes via adapters, but the front rotor must be 160mm minimum.
For drivetrain compatibility, ensure enough clearance between the fork arch and front tire, especially if using wider XC tires or mud-specific treads. The fork works seamlessly with electronic and mechanical drivetrains and includes integrated routing guides for clean cable management.
Comparison with Similar Fork Models
Compared to the Fox 32 Step-Cast Factory, the SID SL Ultimate 2P is lighter and features a more race-oriented damper with quicker lockout response. The Charger Race Day 2 is simpler but delivers impressive performance with minimal weight.
Against the Manitou R7 Pro, the SID SL Ultimate 2P offers more refined adjustability and broader OEM compatibility. While the R7 excels in small-bump compliance, the SID SL maintains better mid-stroke support during high-speed terrain.
If weight is your primary concern, the SID SL Ultimate remains the lightest production XC fork, making it the clear choice for racers prioritizing climbing and acceleration.
Is the SID SL Ultimate 2P Worth the Investment?
The SID SL Ultimate 2P is a niche product targeted at cross-country racers and weight-conscious trail riders. Its lightweight chassis, efficient lockout, and tunable suspension make it a standout choice in competitive XC environments.
For casual trail use or aggressive enduro applications, riders may find its travel and stiffness insufficient. However, within its intended use case, the performance gains are tangible, particularly when climbing or accelerating out of corners.
Its value lies in efficiency, weight reduction, and dependable performance under race stress, making it a worthwhile upgrade for riders aiming to shave seconds off lap times.
Frequently Asked Questions
What’s the maximum rotor size compatible with the SID SL Ultimate 2P?
The fork is rated for rotors up to 180mm with a proper adapter, though 160mm is the minimum size supported without modification.
Can I use the SID SL Ultimate 2P for trail riding?
It is possible, but not recommended. The fork is optimized for cross-country terrain and may not withstand repeated heavy hits or large drops.
How often should the SID SL Ultimate 2P be serviced?
Lower leg service is advised every 50 hours, and full damper and air spring service every 100–200 hours depending on riding intensity.
Is the SID SL Ultimate 2P compatible with remote lockouts?
Yes, it supports both RockShox TwistLoc and OneLoc remote lockout systems.
Does the SID SL Ultimate 2P come with volume spacers?
It typically ships with a stock configuration but includes documentation on how to install optional volume spacers.
What is the weight of the SID SL Ultimate 2P?
The fork weighs approximately 1,326 grams without the remote and axle, making it one of the lightest XC forks on the market.