Cybex Introduces Sirona S: First Convertible Car Seat with Load Leg in North America

Cybex Sirona S Convertible Car Seat Preview: Swivels for Convenience, Load Leg for Safety, SensorSafe for Peace of Mind

Sirona S in Black is currently in stock at BuyBuyBaby. Additional fashions and other retailers are coming soon! We will update when there is more information to share. 

We’re thrilled that Cybex is working on an epic, game-changing convertible car seat: the Sirona S. Not only does Sirona S swivel 360 degrees for easy loading and unloading of children, it will also be the first convertible car seat in North America to have a load leg, a safety feature that significantly enhances crash protection in a frontal crash. As if that wasn’t enough, the Sirona S will also come standard with SensorSafe technology, which is built into the chest clip.

Sirona S Specs & Features:
  • Rear-facing: 4-50 lbs.
  • Forward-facing: 22-65 lbs.
  • LATCH weight limits: 35 lbs. RF, 40 lbs. FF
  • Maximum harness height: 17″
  • Swivels for easy loading or switching between modes
  • Multi-position load leg with indicators
  • No-rethread harness with easy height adjuster
  • 7 recline positions rear-facing
  • 4 recline positions forward-facing
  • SensorSafe chest clip with bluetooth/app reminders and alerts
  • Pop-out Linear Side-Impact Protection
  • MSRP: $499


With features like swivel and load leg that are currently unique to the USA market, plus safety enhancements like LSP and SensorSafe, we deem it a “Shut Up and Take My Money” Award winner!  We acknowledge that $499 is a lot of money for a car seat but just like automobiles, innovations almost always launch on premium products and eventually work their way down to more affordable models. We hope consumers in North America understand and appreciate the safety benefits of a load leg because this is the evolution of crash protection for children!

2019 CarseatBlog Shut Up and Take My Money Award Winner: Cybex Sirona S


Better than a JPMA award!

The Sirona S has a single belt path for both rear- and forward facing, with a seatbelt/lower anchor belt tensioner for simple and secure installation. Once installed, the seat can swivel 360 degrees on its base, allowing parents to get kids in and out without having to lift them over the sides. This can be a convenience for any caregivers, but especially those who might have mobility difficulties. The swivel feature will also make it easy to switch between rear- and forward-facing for situations where two or more kids might share a seat.

An indicator on the load leg will show when the seat is engaged in rear-facing or forward-facing mode since driving with the seat sideways will be neither secure nor allowed!

The telescoping load leg can be used rear-facing and forward-facing. Until now, the US has only seen load legs on rear-facing-only infant seats, so having one that can be used with larger children, rear-facing or forward-facing is a very big deal. For a rear-facing seat, the load leg prevents downward rotation in a frontal crash – maintaining a more upright position throughout the crash. This significantly improves crash protection and also reduces the secondary rebound rotation that a rear-facing car seat will experience in a frontal crash. Additionally, a load leg greatly reduces the likelihood that a rear-facing car seat will make contact with the front seat. For forward-facing, similar principles apply. The load leg will decrease how far the seat moves in a frontal crash, thus reducing head excursion (or how far forward a child’s head moves) in a crash.

As usual, there is a tether on the back of the seat’s shell for forward-facing, and it would need to be unhooked from the tether anchor in the vehicle before you are able to swivel the seat when it’s installed for forward-facing use. We mused whether people would be able to use the load leg in place of the tether to potentially reduce head excursion (in situations where a tether anchor wasn’t available) but at this point, we aren’t sure if that’s even a possibility. Due to current federal regulations, car seat manufacturers can’t use the load leg to comply with FMVSS 213 standards since the test bench doesn’t have a floor. Cybex is testing the seat with load leg using a modified 213 sled, but even then, legal issues (including mandatory tether usage in Canada) make it seem unlikely that Cybex will ever say it’s okay to use the load leg as a substitute for using the tether. Keep in mind that all seats in the US have to pass testing with and without a tether so it’s almost always possible to install a forward-facing car seat without tethering it, **if there is no tether anchor available**. (Note: there are some exceptions for seats rated beyond 65 lbs. in the U.S. that REQUIRE tethering and all forward-facing seats in Canada REQUIRE installation using the tether). The bottom line here is that this is uncharted territory in North America, so it’s going to be complicated for Cybex to navigate these waters.

Cybex plans to release the Sirona S in the United States in fall 2019 with an eventual release in Canada (no timetable for Canada at the moment, sorry). The seat will retail for $499. Stay tuned for more information and a full review when production-model seats are available.

Watch our video for a demonstration of key features. (Note that the seat is NOT actually in full recline position when Kecia states it is. The prototype was a bit sticky. It does recline more for younger babies.)


  1. Klaus June 18, 2021
    • Taniya Sweet August 8, 2021
  2. Jen April 10, 2021
    • Taniya Sweet April 14, 2021
      • Chris May 30, 2021
  3. Sonya Piell March 3, 2021
    • Heather March 4, 2021
  4. Alex January 26, 2021
    • Kecia February 1, 2021
  5. Christine Johnson January 18, 2021
  6. Tea Robin December 19, 2020
  7. Felix July 20, 2020
    • Heather July 21, 2020
  8. Taniya Sweet July 14, 2020
  9. Jose Castro July 11, 2020
    • Heather July 12, 2020
  10. Martha June 25, 2020
    • Heather June 25, 2020
  11. Garrett June 19, 2020
  12. Heidi May 24, 2020
    • Kecia May 25, 2020
      • Timmy March 4, 2021
        • Heather March 7, 2021
  13. Jackie February 14, 2020
    • Kecia February 15, 2020
      • Taniya Sweet March 1, 2020
        • Kecia March 11, 2020
          • Taniya May 23, 2020
    • Kate Slobodin March 7, 2020
  14. Rhi February 6, 2020
    • Kay April 11, 2020
      • Andrea Murillo June 17, 2020
  15. Dave January 2, 2020
    • Heather January 2, 2020
  16. MaryR December 31, 2019
    • Heather January 2, 2020
  17. Aljasmi November 21, 2019
    • Heather November 25, 2019
      • Karys Blake February 16, 2020
        • Heather February 18, 2020
  18. Eva Koster October 25, 2019
    • Kecia October 26, 2019
      • Yulia December 28, 2019
    • Rhiannon November 29, 2019
  19. Lauren jones October 17, 2019
  20. Jennifer Root September 14, 2019
    • Heather September 17, 2019
    • Heather September 18, 2019
    • Staci Morin November 20, 2019
      • Heather November 20, 2019
        • Bo March 2, 2020
          • Kecia March 11, 2020
        • Kate May 13, 2020
      • Kecia November 21, 2019
        • Jason January 14, 2020
          • Heather January 19, 2020
  21. Pa Vang September 14, 2019
    • Heather September 17, 2019
      • Aimee October 15, 2019
        • Heather October 15, 2019
          • DJ Deborah Beck November 5, 2019
          • Heather November 7, 2019