The Specialized Pathfinder Pro 700×38 is a versatile gravel tire designed for mixed-surface performance, offering a balance between speed, grip, and comfort. Setting them up tubeless maximizes their rolling efficiency and puncture resistance. This guide explains in detail how to correctly mount, seal, and maintain these tires for optimal performance.
Tools Required
- Tubeless-compatible rims (width suitable for 700×38 tires)
- Tubeless rim tape (correct width for your rim)
- Tubeless valves
- Tire levers (plastic, non-metallic)
- Sealant injector or squeeze bottle
- Tubeless tire sealant (recommended: 60–90 ml per tire)
- Floor pump or tubeless-specific inflator
- Isopropyl alcohol and clean rags
Preparing the Rim for Tubeless Setup
Before mounting the Pathfinder Pro 700×38, ensure the rim is completely tubeless-ready. Remove any old rim tape and inspect the inner rim surface for cracks, sharp edges, or debris. Clean the rim bed with isopropyl alcohol to remove grease and dust. Apply the tubeless rim tape with consistent tension, overlapping the starting point by at least 10 cm. Press the tape firmly into the rim bed, ensuring there are no wrinkles or air pockets. Puncture the valve hole precisely with a small pick or awl before inserting the tubeless valve.
Mounting the Pathfinder Pro 700×38
Start by seating one bead of the tire onto the rim by hand. For the second bead, begin opposite the valve and work evenly around the rim. If the bead feels tight, use a plastic tire lever carefully to avoid damaging the bead. Avoid twisting or kinking the tire during mounting, as this can make inflation more difficult.
Adding Tubeless Sealant
Once one bead is fully seated and the second bead is partially mounted, inject the recommended amount of sealant directly into the tire. Specialized Pathfinder Pro 700×38 tires generally perform best with 60–90 ml of sealant, depending on rim width and intended use. Rotate the wheel to distribute the sealant before fully seating the final bead.
Seating the Beads and Initial Inflation
Use a floor pump or a tubeless inflator to rapidly seat the beads. High initial airflow is essential for the Pathfinder Pro to snap into place without leaks. Listen for a series of sharp pops, which indicate the bead is engaging with the rim hook. Once seated, inflate the tire to 50–60 psi temporarily to ensure both beads are fully locked.
Sealing and Shaking Process
After the beads are seated, shake and rotate the wheel in multiple orientations to allow the sealant to coat the inner tire walls completely. Focus on the sidewalls, as they are the most common source of air loss in new tubeless setups. Lay the wheel flat for a few minutes on each side before reinstalling it on the bike.
Pressure Optimization for Riding
For the Pathfinder Pro 700×38, optimal tubeless pressure depends on rider weight, terrain, and riding style. On mixed gravel and pavement, most riders find 35–45 psi delivers an ideal balance of comfort and rolling speed. Lower pressures improve grip and comfort but may increase rolling resistance on smooth roads.
Troubleshooting Common Tubeless Issues
If the tire will not seat, check that the rim tape is properly applied and that no sealant is blocking the valve. In cases of slow air loss, rotate the tire to allow sealant to reach potential leak points. If a persistent leak remains, deflate the tire, inspect for debris or bead damage, and reapply sealant if necessary.
Maintenance for Long-Term Performance
Tubeless setups require periodic maintenance to remain airtight. Check tire pressure before each ride, and top up sealant every 2–3 months, as it can dry out over time. Inspect the tread and sidewalls for cuts or embedded debris. If the bead becomes loose after many months of riding, re-taping the rim can restore a secure fit.
Customization and Performance Optimization
While the Pathfinder Pro 700×38 already offers excellent all-round performance, riders can fine-tune their setup. Wider internal rim widths (21–25 mm) improve sidewall stability and cornering precision. For mixed terrain races, combining these tires with a lighter sealant can reduce rotational weight slightly without sacrificing puncture protection.
Compatibility with Other Drivetrain and Wheel Systems
The Pathfinder Pro 700×38 is fully compatible with modern gravel and all-road tubeless wheel systems, including both hookless and hooked rims, provided they meet ETRTO width standards. Always check rim and tire compatibility charts before installation to ensure bead security and safe operating pressures.
Comparing the Pathfinder Pro 700×38 to Similar Models
Compared to the Pathfinder Pro 700×42, the 38 mm version offers faster acceleration and better road efficiency, making it suitable for riders who prioritize speed over maximum comfort. Against competitors like the WTB Byway or Panaracer GravelKing SS, the Pathfinder Pro provides a more balanced tread for mixed terrain, combining a smooth centerline with grippy side knobs for cornering stability.
FAQs
1. Can the Pathfinder Pro 700×38 be mounted with tubes?
Yes, although it is optimized for tubeless setups, it can be run with standard inner tubes.
2. How much sealant should I use?
Typically, 60–90 ml per tire, depending on rim width and riding conditions.
3. Are these tires compatible with hookless rims?
Yes, provided the rim meets the manufacturer’s tubeless compatibility and pressure guidelines.
4. How often should I refresh sealant?
Every 2–3 months, or sooner in hot climates.
5. What’s the recommended break-in period?
About 50–100 km of mixed terrain riding helps the tire casing and sealant fully settle.
6. Can I use a CO₂ inflator to seat the bead?
Yes, but it’s best used only for seating; CO₂ can cause some sealants to solidify faster.