The SID SL Ultimate 3P from RockShox stands out as one of the most refined cross-country suspension forks currently on the market. Engineered specifically for elite XC racing, it blends weight savings, efficient lockout control, and responsive damping into a package that satisfies professional and amateur racers alike. Below is a detailed guide that examines the top features of this model, providing essential insights for installation, adjustment, maintenance, optimization, and more.
Installation Guidelines for the SID SL Ultimate 3P
Installing the SID SL Ultimate 3P requires precise attention to torque values and alignment. The fork uses a standard tapered steerer and is compatible with modern XC frames designed around Boost axle spacing.
Prior to installation, ensure that the crown race matches your headset specifications. Grease the steerer tube lightly to prevent corrosion. Insert the fork into the head tube, install the appropriate headset spacers, and tighten the stem bolts uniformly to the manufacturer’s torque settings. The fork features a 110 mm Boost spacing, so make sure your hub matches this specification before fitting the wheel.
When installing the brake caliper, align it precisely with the post-mount tabs and torque to spec. The 3P (three-position) remote lockout also requires precise cable routing to avoid interference. Ensure the cable housing is trimmed to prevent binding and allow for smooth actuation.
Adjustment for Performance and Ride Quality
The SID SL Ultimate 3P offers a wide range of adjustment options to tailor ride performance. The three-position remote—Open, Pedal, and Lock—lets riders adapt to terrain changes without releasing their grip from the handlebars.
Air spring pressure should be set based on rider weight and sag preference. RockShox provides a detailed chart, but fine-tuning by feel is often more effective. To measure sag, slide the O-ring against the wiper seal, mount the bike in full gear, and bounce slightly before settling into riding posture. The O-ring position indicates sag, which should typically fall between 15-25% of the fork’s travel.
Rebound adjustment is managed via a red dial at the bottom of the fork’s right leg. Faster rebound settings suit aggressive terrain, while slower settings help maintain control on smoother trails. The SID SL does not include compression adjustment beyond the 3P remote, streamlining tuning for XC-focused riders.
Routine Maintenance and Service Intervals
Regular maintenance is essential to preserving the performance and longevity of the SID SL Ultimate 3P. Dust wipers should be inspected and cleaned after every few rides, especially in dry or muddy conditions.
A lower leg service, including oil replacement and seal lubrication, is recommended every 50 hours of ride time. Full damper and air spring services should be conducted at 100–200 hour intervals depending on usage intensity. RockShox service kits are readily available, and many procedures can be done with basic tools and mechanical knowledge.
Use only RockShox-approved suspension fluids and avoid over-lubrication, as excess oil can attract dirt. Always check for wear or contamination on the foam rings and replace them when necessary.
Troubleshooting Common Setup Issues
Several issues can affect the fork’s performance if not addressed during setup. Inconsistent lockout performance is often due to incorrect cable tension or housing interference. Confirm the remote cable is properly clamped and that housing is not kinked or excessively long.
If the fork feels harsh or fails to reach full travel, verify that air pressure is appropriate for rider weight and that negative and positive chambers are balanced. This can be done by fully compressing the fork and then allowing it to extend naturally.
Unusual noises or lack of rebound damping may indicate contamination or air migration within the damper. In such cases, a full service is recommended to restore damping performance.
Customization and Optimization Techniques
Riders looking to push the SID SL Ultimate 3P further can benefit from several tuning options. Volume spacers in the air spring can be added or removed to change the progression curve. Adding spacers increases end-stroke support, ideal for aggressive descents, while removing them results in a more linear feel.
Aftermarket upgrades such as titanium bolts and carbon remote levers can further reduce weight. Additionally, pairing the fork with a RockShox TwistLoc remote can offer cleaner cockpit integration and quicker actuation.
Cockpit ergonomics can be improved by adjusting the angle and lever throw of the remote. Optimizing this positioning allows quicker transitions between ride modes during competition.
Compatibility with Drivetrain and Frame Standards
The SID SL Ultimate 3P is designed with modern XC standards in mind. It uses a 44 mm offset and 29-inch wheel compatibility, suiting frames with progressive geometry. The Boost 110 mm spacing ensures alignment with modern wheelsets.
The fork’s post-mount disc brake interface is optimized for 160 mm rotors but can be adapted up to 180 mm using spacers. Compatibility with SRAM and Shimano drivetrains is seamless due to the fork’s neutral design regarding cable routing and clearance.
The steerer tube is a standard 1.5″ to 1-1/8″ tapered format, which integrates smoothly with current XC headset systems. However, compatibility with older non-Boost frames or 26-inch wheels is limited.
Comparison with Similar XC Forks
Compared to the Fox 32 Step-Cast, the SID SL Ultimate 3P offers similar weight savings but edges ahead in remote lockout functionality with its three-position system. The Fox model offers a two-position remote (open/lock) by default, requiring an upgrade for mid-platform options.
The SID SL also has a stiffer chassis thanks to its 32 mm stanchions and re-tuned Charger Race Day damper. While both forks prioritize lightweight performance, RockShox leans more toward race-specific features, whereas Fox offers broader adjustability for general trail use.
The SID SL Ultimate’s air spring tuning and ability to use volume tokens give it a broader tuning range for racers seeking either plushness or end-stroke ramp-up.
Tools Required
- 4 mm, 5 mm, and 6 mm hex wrenches
- Torque wrench [paid link] with NM scale
- Shock pump (for air pressure adjustment)
- Clean lint-free cloths
- Suspension grease (RockShox-approved)
- Suspension fluid for 50/100 hour services
- Lower leg service kit
- Crown race setter
- Zip ties or cable clamps for remote housing
Frequently Asked Questions
Q1: What is the travel range for the SID SL Ultimate 3P?
The SID SL Ultimate 3P is offered with 100 mm travel, optimized for XC racing with minimal chassis flex.
Q2: Can I install this fork on a trail bike?
It’s not recommended. The SID SL is optimized for cross-country geometry and weight demands. Trail bikes generally require stiffer, longer-travel forks.
Q3: How often should I service this fork?
Lower leg service is recommended every 50 hours. A full damper and air spring service should be done every 100 to 200 hours.
Q4: Is the 3P remote compatible with SRAM TwistLoc?
Yes, the 3P remote system is fully compatible with SRAM TwistLoc for cleaner cable routing and faster engagement.
Q5: Can I upgrade the damper?
No, the SID SL Ultimate already comes with the Charger Race Day 2 damper, RockShox’s premium lightweight unit. Other dampers are not supported due to chassis constraints.
Q6: Does it support 27.5″ wheels?
No, the SID SL Ultimate 3P is exclusively designed for 29-inch wheels, and using smaller wheels would compromise geometry and axle-to-crown height.
Conclusion
The RockShox SID SL Ultimate 3P is a purpose-built cross-country suspension fork that blends elite-level performance with race-specific features. Its lightweight design, 3P remote lockout, and precise adjustability make it a top choice for XC racers looking for an edge on the competition. With proper setup and maintenance, it delivers consistent, reliable performance in the most demanding race conditions.