The RockShox SID SL Ultimate 2P is a premium XC suspension fork designed for racing efficiency and lightweight performance. It features a 2-position remote lockout (2P), a Charger Race Day damper, and a DebonAir air spring, making it ideal for competitive cross-country riders who demand precision. Tuning and maintaining this fork correctly ensures optimal responsiveness, longevity, and trail feedback. This guide walks through the installation, adjustment, maintenance, and optimization of the SID SL Ultimate 2P, focusing solely on this specific model.
Tools Required
- 6mm and 5mm hex keys [paid link]
- Torque wrench [paid link] (2-15 Nm range)
- Shock pump
- Suspension grease (RockShox PM600 or Slickoleum)
- Clean rags and isopropyl alcohol
- Lower leg service kit
- Suspension oil (RockShox 0W-30 and Maxima Plush)
- Circlip pliers (for damper service)
- Remote bleed kit [paid link] (if remote is hydraulic)
Installation of the SID SL Ultimate 2P
Proper installation of the SID SL Ultimate 2P begins with correct steerer tube cutting, crown race placement, and precise torque on all hardware. This fork is compatible with 29” wheels, Boost spacing (15×110 mm), and flat-mount disc brakes.
Begin by pressing the crown race gently but firmly into place using a crown race tool. After determining the correct steerer tube length, cut it cleanly with a saw guide. Deburr the edge, install a star nut or compression plug, and slide the fork into the headtube. Torque the stem bolts evenly to 5–6 Nm. Ensure the brake caliper aligns perfectly with the rotor before tightening the bolts.
Attach the remote lockout (TwistLoc or OneLoc, depending on model) and route the cable cleanly along the frame. If it’s a hydraulic remote, bleed the system thoroughly after installation.
Air Spring Adjustment for Rider Weight
The SID SL Ultimate 2P uses the DebonAir air spring, which should be tuned according to rider weight for optimal performance. RockShox provides a recommended air pressure chart based on rider weight, but fine-tuning may be necessary.
Begin by setting the sag to 15–20% of the total fork travel (100mm or 110mm, depending on version). Inflate the air spring using a shock pump, and have the rider sit in riding position with gear on. Use the O-ring to measure the sag. Adjust air pressure until the desired sag is achieved.
Volume spacers can be added or removed to modify spring progression. More tokens result in a firmer mid-stroke and bottom-out resistance, ideal for aggressive riders. Fewer tokens make the fork feel more linear, enhancing small bump sensitivity.
Tuning Compression and Rebound Damping
The SID SL Ultimate 2P has simplified damping adjustment via the Charger Race Day damper. The 2-position switch allows open and lock modes—ideal for climbs and descents. While it lacks low-speed compression adjustability, rebound damping can be dialed in using the red knob on the fork leg.
To adjust rebound, turn the red dial clockwise for slower rebound (ideal for control) and counter-clockwise for faster rebound (better for small bump compliance). A general rule is to find a setting where the fork returns quickly without bucking the front wheel.
Lockout force can be tuned via internal shim stacks, but this requires advanced technical skill and should only be performed during a full damper service.
Maintenance Intervals and Procedures
The SID SL Ultimate 2P requires consistent maintenance to maintain performance and prevent premature wear. RockShox recommends lower leg service every 50 hours and a full damper and air spring overhaul every 100–200 hours, depending on conditions.
During a lower leg service:
- Remove the lower legs after draining oil.
- Clean stanchions and seals with isopropyl alcohol.
- Inspect foam rings and replace if contaminated.
- Re-lubricate seals with suspension grease.
- Refill with the correct oil volume (10ml Maxima Plush per leg).
Damper service is more complex and should be done with care. It involves bleeding the Charger Race Day damper, which requires circlip pliers, bleed syringes, and specific oil weights.
Troubleshooting Common Setup Issues
New users often encounter issues with poor small bump compliance, excessive dive, or harshness. These can usually be traced back to incorrect air pressure, lack of lubrication, or overly open rebound settings.
If the fork feels harsh, first ensure that proper sag is set. Next, check if the foam rings are dry or contaminated. If dive occurs too easily, consider adding a volume spacer. If the fork packs down over repetitive hits, slow the rebound slightly.
Another common issue is inconsistent lockout performance, which may stem from incorrect cable tension or air bubbles in the hydraulic remote. Re-check cable routing and perform a fresh bleed if necessary.
Compatibility with Drivetrain and Braking Systems
The SID SL Ultimate 2P is compatible with 1x and 2x drivetrains as long as cable routing does not interfere with the remote. Its Boost axle allows compatibility with modern 29” XC wheels. The fork uses a flat-mount brake design with a 160mm minimum rotor size and fits standard post-mount calipers via adapters.
It is essential to use a flat-mount brake adapter and ensure rotor size doesn’t exceed fork specifications. Avoid mismatched rotors, as it can lead to caliper misalignment and rotor rub.
Customizing Performance with Aftermarket Upgrades
Several aftermarket upgrades can enhance the SID SL Ultimate 2P’s performance. Volume spacers (tokens), different remote levers (like TwistLoc), and lightweight titanium hardware are common modifications.
Custom decals, axle upgrades (e.g., RockShox Maxle Stealth), and improved seals like SKF low-friction wipers also help enhance both aesthetics and function. For riders demanding more mid-stroke support, tuning the DebonAir air spring with more volume spacers is effective.
Riders focused on weight savings can replace the crown-mounted remote with a lighter handlebar-mounted option and choose lightweight rotors to reduce front-end mass.
Comparison with Similar XC Fork Models
The SID SL Ultimate 2P stands apart from other XC forks like the Fox 32 Step-Cast Factory and DT Swiss F 232 One due to its balance of simplicity, weight, and lockout performance.
While the Fox 32 SC offers more compression adjustments, the SID SL excels in weight savings and ease of service. The DT Swiss F 232 is similarly lightweight but lacks the smoothness and tuneability of the DebonAir spring.
In short, for racers who prefer set-and-forget performance and consistent lockout actuation, the SID SL Ultimate 2P provides the ideal package.
FAQs
What rider weight is the SID SL Ultimate 2P designed for?
It suits a wide range of riders from 50kg to 100kg, with air pressure recommendations based on weight. Fine-tuning with sag and volume spacers is recommended.
Can I use this fork for trail or enduro riding?
No. It is designed strictly for cross-country use and lacks the travel and chassis strength for aggressive trail or enduro riding.
How often should I service the fork?
A lower leg service every 50 hours and a full overhaul every 100–200 hours, depending on conditions, is recommended.
Is the lockout hydraulic or cable-actuated?
It depends on the remote. TwistLoc is typically mechanical, while OneLoc can be either. Always check your remote version before servicing.
Does this fork support tire sizes above 2.4”?
No. The clearance is optimized for tires up to 2.4” in width on 29” rims.
Can I convert it to a longer travel version?
Only within limits. The SID SL is factory-limited to 100mm or 110mm travel options. Modifying beyond that is not recommended due to chassis constraints.
Conclusion
The RockShox SID SL Ultimate 2P is a highly refined, lightweight XC fork offering simplicity, lockout efficiency, and tuning precision. By following proper installation, regular maintenance, and thoughtful tuning, riders can extract the maximum performance from this premium component. This guide provides all the essential steps to help both beginners and experienced cyclists achieve a top-performing front end tailored to their riding style.