(4 customer reviews)

STX Inertia Road Folding Tire


The Serfas® STX Inertia Folding Road Tire features a smooth tread constructed using our high performance Alchemy Compound for lower rolling resistance and world class grip.

Comprehensive testing at Wheel Energy® of Finland, an independent tire laboratory, found Serfas® Inertia tires to perform 8.12% better at cornering than our competitor’s most comparable best selling road bike tire.

  • Serfas® FPS Flat Protection
  • Dual Density Tread Compound
  • 120 TPI 3-Layer Casing
  • Low Rolling Resistance Alchemy Compound w/ World Class Grip

This product is currently out of stock and unavailable.



30 Day Warranty
Serfas® Tires are covered by our 30 Day Warranty which guarantees a product free of defects in material and/or workmanship up to 30 days after purchase. This warranty does not apply to damage due to heat, environmental factors, misuse, or negligence. *Tire purchase must be from authorized Serfas® retailer for eligibility.


  • Alchemy Compound For Low Rolling Resistance and World Class Grip
  • FPS Flat Protection System
  • Dual Density Tread
  • Smooth Tread Pattern For Ultimate Performance
  • 120 TPI 3 Layer Construction Provides Supple Ride


  • Bead: Folding
  • TPI: 120
  • Sizes:
    • 700 x 23
    • 700 x 25
    • 700 x 28
  • Pressure: 130 PSI
  • Weight:
    • (23) 222g
    • (25) 242g
    • (28) 312g

4 reviews for STX Inertia Road Folding Tire

  1. Mark Solow

    I’ve been a Continental 4k, 4kS, and 4kSII fan for several years. Just put a set of these (700×25) Inertia’s on my carbon roadie after getting a sidewall blow-out on my (700×25) Conti’s. They way outperformed what I expected! The grip on corners was unmatched—which is what Conti says makes theirs faster. Plus, the ride comfort was smoother too. So, I put a set on my wife’s bike and she loves the ride too. We both think that they are faster, but can’t confirm. Could just be riding faster because we like the way they feel.

  2. Mark Solow

    Update: Have now ridden these over 1,500 miles still with good grip and no flats!

  3. Mark Solow

    Update: Over 3,000 miles. Still round. Still decent grip. Still no flats. Amazing! Unquestionably the best tire I’ve ridden in the 10 years I’ve been riding 5-6 times a week!

    • Serfas

      Mark, Great to hear how well the Intertia has and is continuing to perform for you over all those miles! Thanks for sharing your experience – The Serfas Team

  4. J. Villanueva

    These tires are special! Woke up to ride and noticed My front wheel had a flat due to a small piece of glass. Went to my local bike shop and picked up these in a 28 ( previously running 25 ). Just went with the bigger tires just out of curiosity and im glad I did. Went on a big climb right right after and i was blown away on how well these tires performed. I felt a lot faster in the climb and on the decent i felt alot more stable ( 260 lbs is what iI weigh ). Averaging 7 mph on a six perecent grade at my weight just felt alot easier compared to the 25’s Vittoria. Serfa hit the spot on these

    • Serfas

      Thank you for your feedback! We appreciate you sharing your positive experience with us and hope you continue to enjoy the performance of our Inertia road tires, thank you again! – The Serfas Team

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Tire Sizes

700×23 Folding, 700×25 Folding, 700×28 Folding