The RockShox SID Ultimate 3P suspension fork has become a preferred choice among cross-country (XC) and marathon racers due to its lightweight construction, performance-tuned damping, and intelligent remote-controlled damping modes. Built for speed and precision on challenging terrain, this fork is a result of RockShox’s continual engineering refinement. This guide explains in technical detail the installation, tuning, and upkeep of the SID Ultimate 3P, while also addressing common setup problems, compatibility concerns, and model comparisons.
Tools Required
- Torque wrench [paid link] with hex bits (2mm–8mm)
- Suspension pump with digital pressure gauge
- Shock oil and RockShox service kit (for lower leg maintenance)
- Isopropyl alcohol and clean rags
- Crown race setter and star nut installation tool
- Remote lever setup tool (for 3P models)
- Bike stand [paid link] and Allen key set
Installation Procedure
Installing the SID Ultimate 3P requires careful handling due to its lightweight components and integrated 3-position remote functionality. Begin by ensuring the steer tube is cut to match your bike’s headtube and headset configuration. Apply a crown race compatible with your headset, then press it securely onto the fork using a race setter tool.
Mount the fork to the frame and torque the headset cap bolt to the manufacturer’s specifications. Be sure to align the fork’s brake hose port and route the cable cleanly through the frame to the caliper. Install the brake caliper using the correct post-mount adapters and torque to the recommended settings.
Mount the 3P remote lever on the handlebar. Depending on your cockpit setup, you may choose left or right side placement. Route the cable to the damper-side top cap and connect it using the indexed slots provided. Confirm that all three positions—Open, Pedal, and Lock—engage cleanly.
Initial Suspension Setup and Adjustment
Tuning the SID Ultimate 3P begins with setting the appropriate sag, which typically ranges between 15% and 25% of travel for XC racing. Use the suspension pump to pressurize the Solo Air chamber to the rider’s weight specification, usually between 70 to 120 psi.
Adjust rebound by turning the red dial at the bottom of the right fork leg. Faster rebound is suitable for smoother courses, while slower rebound improves control on technical trails. Each rider should fine-tune this based on terrain and riding style.
The 3P remote lever controls compression damping. In the Open mode, the damper provides full plushness for descending. Pedal mode firms up low-speed compression, optimizing efficiency for rolling terrain. Lock mode nearly closes the compression circuit, ideal for sprinting or climbing on pavement.
Maintenance Requirements
Routine maintenance extends the fork’s lifespan and maintains peak performance. After every 50 hours of ride time, clean the stanchions and inspect for oil residue or wear marks. Use isopropyl alcohol to clean the lowers and ensure the dust wipers are intact.
A lower leg service should be performed every 100 hours or annually. This includes replacing the bath oil, cleaning foam rings, and inspecting the air spring. Use the RockShox service kit specific to the SID Ultimate 3P model. During this service, also check the remote actuation for cable stretch and adjust tension as needed.
Damper service is more complex and typically recommended every 200 hours. This requires specialized tools and precise bleeding procedures for the Charger Race Day 2 damper.
Troubleshooting Common Set-Up Issues
Several common setup challenges can affect SID Ultimate 3P performance. Riders may experience a lack of engagement in the 3P lever. This is often due to incorrect cable tension or a misaligned remote cam. Re-adjust the cable and ensure the lever indexes cleanly into each mode.
If the fork feels harsh in Open mode, air spring pressure may be too high, or negative spring balance may be off. Equalize the positive and negative chambers by cycling the fork after inflation. Additionally, a sluggish rebound often points to clogged rebound circuits or incorrect oil viscosity during service.
Brake rub can occur if the fork’s post mount tabs are not aligned. Use thin washers to space the caliper properly or face the tabs if needed.
Customization and Performance Optimization
The SID Ultimate 3P supports several customization options. Riders can install Bottomless Tokens in the air spring to alter the progression curve. More tokens increase bottom-out resistance, ideal for aggressive XC courses with big hits.
Swapping the stock remote lever for an integrated handlebar setup like TwistLoc or pairing with SRAM’s AXS dropper can streamline the cockpit. Riders can also adjust offset options to tune handling characteristics based on frame geometry.
To reduce overall weight, the SID Ultimate’s carbon crown and steerer can be used with lighter axles and titanium hardware kits. Tire clearance allows for up to 2.4” tires, providing flexibility for different terrain and rider preferences.
Compatibility With Drivetrain and Frame Standards
The SID Ultimate 3P is built around modern XC frame and drivetrain standards. It supports 110mm Boost axle spacing and is designed for use with flat-mount or post-mount brakes depending on frame requirements. The fork accommodates both 29” and 27.5” wheels depending on the selected variant.
Rotor compatibility includes up to 180mm rotors without the need for adapters, making it suitable for demanding race setups. It integrates well with SRAM’s electronic and mechanical drivetrains, especially when combined with RockShox’s wireless dropper posts.
The fork’s steerer tube is 1.5” to 1 1/8” tapered, fitting most modern carbon and aluminum XC frames. Ensure headset bearing standards match this specification for correct installation.
Model Comparison: SID Ultimate 3P vs. SID Select and SID SL
Compared to the SID Select and SID SL, the Ultimate 3P stands out with its premium Charger Race Day 2 damper, remote-adjustable 3-position compression, and carbon chassis elements. The SID SL is lighter but limited to 100mm travel and lacks the remote compression adjustment.
SID Select models use the Rush RL damper, which offers less precise damping control and lacks the three-mode remote functionality. For racers who demand maximum adjustability and weight savings, the SID Ultimate 3P offers the most complete package.
SID Ultimate also features Maxima Plush damping fluid and SKF low-friction seals, which contribute to smoother small bump compliance and longer service intervals.
FAQs
1. Can I run the SID Ultimate 3P with non-Boost wheels?
No. The fork is designed for Boost spacing (110mm). Running non-Boost wheels would require spacers and compromise alignment.
2. How do I know if the 3P remote is properly indexed?
Each click should engage a distinct mode. If one mode feels loose or doesn’t engage, check cable tension and housing routing.
3. What is the maximum rotor size compatible with this fork?
It supports up to 180mm rotors without adapters. For larger sizes, aftermarket adapters may be necessary.
4. Can I install this fork on a hardtail frame?
Yes, provided the frame supports tapered steerers and Boost hub spacing. It’s a popular upgrade for lightweight race hardtails.
5. How often should I perform a lower leg service?
Every 100 hours or once a year, whichever comes first. More frequent service may be needed in muddy or dusty conditions.
6. Are there any air spring tuning options available?
Yes. Bottomless Tokens can be added or removed to adjust ramp-up and bottom-out characteristics.