The RockShox SID SL Ultimate 2P is a flagship cross-country suspension fork designed for competitive mountain biking. Known for its lightweight design and race-focused features, it promises top-tier performance for riders pushing their limits on XC trails. This guide provides a detailed look at the installation, adjustment, maintenance, and overall performance of the SID SL Ultimate 2P.
Tools Required:
- Torque wrench [paid link] with hex and Torx bits
- Crown race setter
- Suspension pump
- Caliper for measuring sag
- Grease and carbon paste
- Shock oil and bleed kit [paid link] (for service)
Installation Guide for the SID SL Ultimate 2P
Proper installation of the SID SL Ultimate 2P ensures optimal performance and durability. Begin by ensuring frame compatibility; this fork is designed for 29-inch wheels and uses a Boost (110mm) axle spacing.
Start with pressing in the crown race. This must match your headset standard. Once the crown race is seated, slide the steerer tube into the head tube, adjusting spacers and stem before cutting the steerer. Use a pipe cutter or fine-toothed saw, and always leave room for headset preload. Apply carbon paste on carbon steerer tubes to prevent slippage.
Attach the fork using a headset preload cap and torque the stem bolts to manufacturer specs. Install the front wheel with the included Maxle Stealth thru-axle. Ensure the brake caliper is aligned and the rotor does not rub.
Adjustment for Rider Weight and Terrain
The SID SL Ultimate 2P uses the Charger Race Day damper and DebonAir spring, both of which offer limited but precise external adjustability for XC racing.
Set sag by adjusting air pressure via the Schrader valve on the left leg. Use a shock pump to match RockShox’s recommended air pressure chart based on rider weight. Aim for 15-20% sag for XC performance. Rebound damping is adjusted via a red knob on the bottom of the right leg. This fine-tunes how quickly the fork returns after compression.
The “2P” model features a two-position remote lockout (open and locked). Route the cable cleanly through the crown and ensure it actuates the damper correctly. This lockout allows on-the-fly changes for climbs and flats.
Routine Maintenance and Service Intervals
Regular maintenance ensures long-term performance of the SID SL Ultimate 2P. RockShox recommends lower leg service every 50 hours and a full damper service every 200 hours.
To perform a lower leg service, remove the lower legs by releasing the bolts and tapping them gently. Drain the old oil, clean stanchions and inside of lowers, then re-grease seals and reassemble with fresh oil. Use 10wt suspension oil unless specified otherwise in service documents.
Full damper servicing requires bleeding the Charger Race Day cartridge and should be done by experienced mechanics or through RockShox service centers.
Common Set-Up Issues and Troubleshooting
Some users may encounter issues like excessive stiction, air spring noises, or incomplete lockout engagement. Excessive stiction often results from dry or dirty seals; this can be resolved with a lower leg service.
Air spring noises are typically harmless and result from internal air transfers. If it persists or worsens, consider servicing the air spring assembly. Incomplete lockout engagement usually results from poor cable tension or misaligned housing—ensure the remote is properly adjusted and the inner cable slides freely.
Optimizing SID SL Ultimate 2P for Race Performance
To extract maximum performance, minimize unsprung weight by pairing this fork with lightweight carbon wheels and a rigid cockpit. Running tire pressures and fork settings optimized for each race can shave seconds off your time.
Use the lockout strategically during climbs and flats to maintain pedaling efficiency. Experiment with slightly less rebound damping on rooty descents for more traction.
Weight weenies can further reduce grams by replacing the remote lever with an ultralight version or trimming excess steerer tube length.
Compatibility with Drivetrain and Frame Standards
The SID SL Ultimate 2P supports 100mm of travel and is best matched with lightweight XC frames featuring similar travel. It uses a tapered steerer (1.5” to 1-1/8”) and Boost axle spacing, so ensure your frame and wheels match these specs.
It is brake-compatible with post-mount calipers and designed for 160mm rotors, although adapters can be used for 180mm setups. Ensure cable routing does not interfere with the fork crown during full compression.
This fork is not suitable for downcountry or trail use due to its limited travel and stiffness profile.
Comparison with Similar Models
Compared to the Fox 32 Step-Cast, the SID SL Ultimate 2P is slightly lighter and offers a firmer platform when locked out. The Charger Race Day damper is also considered more race-tuned than Fox’s GRIP or FIT4.
However, the SID SL offers fewer external adjustments, which can be a downside for riders who want full control. On the other hand, its simplicity and lightweight appeal to elite racers focused on efficiency.
The standard SID (non-SL) offers more travel and stiffness but at a weight penalty, making the SL better for pure XC courses.
FAQs
1. What tire width can the SID SL Ultimate 2P accommodate?
It fits up to 2.4″ tires, although 2.35″ is recommended for optimal clearance in muddy conditions.
2. Can I upgrade from a standard SID to the Ultimate 2P?
Yes, provided your frame and wheel standards match. Ensure your remote is compatible with the 2-position damper.
3. Does the SID SL Ultimate 2P come with a remote lockout?
It includes a TwistLoc or OneLoc remote depending on the version purchased. Check the product package or dealer.
4. How often should I service the SID SL Ultimate 2P?
Perform lower leg maintenance every 50 hours and full damper service every 200 hours of riding.
5. Is the SID SL Ultimate 2P good for heavier riders?
It is optimized for lightweight racers under 90kg. Heavier riders may find better performance in the standard SID model.
6. What makes the SID SL Ultimate 2P better than a regular suspension fork?
Its weight, stiffness-to-weight ratio, and race-tuned damper make it ideal for competitive cross-country racing.
Conclusion
The RockShox SID SL Ultimate 2P is purpose-built for elite XC racing, offering exceptional weight savings, race-tuned damping, and streamlined adjustments. Its performance, when properly installed and maintained, positions it as one of the top choices for serious racers. While not suited for aggressive trail use, its focus on speed, control, and reliability makes it a benchmark in the cross-country category.