7Rank 07 of 8 · Best i-Size Car Seats
Cybex Cybex Sirona Ti
One of only six seats rated "gut" in ADAC's May 2026 round, with an integrated support leg needing no separate base. ADAC's own verdict: "safe, but very heavy" at 13.5 kg.
7.5BPR score
- €480Price
- 2.5 (ADAC/ÖAMTC 05/2026)ADAC / ÖAMTC overall grade
- 7 of 8in Best i-Size Car Seats
- 7.5BPR score 0–10
Review
What this product is
Written after the analysis, from the same sources the score is built on: the manufacturer's documentation, available studies and verified owner feedback.
The most recently tested seat here, and a solid rather than outstanding result. ADAC graded it 2.5 in the May 2026 round — safety 2.1, handling 2.9, ergonomics 2.1, harmful substances 1.0 — making it one of only six seats rated "gut" out of 26 tested that round.
Context matters for that statistic: of the 26 seats in May 2026, six were good, sixteen satisfactory, three adequate and one failed outright. A 2.5 sits at the bottom of the good group, but the group itself was small.
The distinguishing feature is the integrated support leg — no separate base is needed, which reduces cost and complexity compared with base-and-carrier systems. Approval is 40 to 105 cm, maximum 19 kg, under R129/03, with 360° rotation and rear-facing to 105 cm. The newborn insert covers 40 to 60 cm, one of only two confirmed here.
ADAC's verdict is literally "safe, but very heavy". At 13.5 kg this is the second-heaviest seat in the ranking, and handling at 2.9 is the weakest score of any recommended seat here. Both point the same way: this seat installs once and stays put.
ADAC also states an 8-year usable life under normal use — a rare concrete figure in a category where "expiry" is usually vague, and useful for judging whether to keep a seat for a second child.
On the L.S.P. side-impact system: Cybex's claim of up to 25% force reduction is explicitly internal testing, not independent verification. Side-impact testing has been mandatory under R129 since 2013, so every seat in this ranking passes one. Branded systems describe how a seat achieves that, not whether it does.
At €480 street — against a €399.95 RRP on Cybex's own site — this is expensive for a 2.5, and the €149 Graco matched its 2.1 safety sub-score.
Technical data
Specification
Figures from the manufacturer's documentation, verified against available outside sources. Values we could not confirm are marked as declared.
- Approval
- UN ECE R129/03 (i-Size)
- Height range
- 40-105 cm, max 19 kg
- Orientation
- 360° rotating; rear-facing to 105 cm
- ADAC overall grade
- 2.5
- Safety (Sicherheit)
- 2.1
- Handling (Bedienung)
- 2.9
- Ergonomics (Ergonomie)
- 2.1
- Harmful substances (Schadstoffe)
- 1.0
- Installation
- ISOFIX with integrated support leg
- Seat weight
- 13.5 kg
- Newborn insert
- 40-60 cm
- Stated usable life
- 8 years under normal use (ADAC)
- Test round
- May 2026
- Price
- EUR 399.95 RRP (Cybex); approx. EUR 480 market price (ADAC)
Component scores
Where the score
comes from.
Four components, equal weight, each on a 0–10 scale and each resting on a named source. The overall score is their mean — the full procedure is in the methodology.
What we liked
- One of only six seats rated gut in ADAC's May 2026 round of 26
- Most recently tested seat in this ranking
- Integrated support leg — no separate base needed
- Clean 1.0 for harmful substances
- Newborn insert range confirmed at 40-60 cm
- ADAC states an 8-year usable life
Worth knowing
- 13.5 kg — ADAC's verdict is "safe, but very heavy"
- Handling 2.9, the weakest of any recommended seat here
- €480 street price for a 2.5 grade
- Same 2.1 safety sub-score as the €149 Graco
- L.S.P. force-reduction claim is internal testing, not independent
- No belt installation option
Comparison
How it compares
within the category
All values come from the same analysis and are comparable only within the category Best i-Size Car Seats.
| Product | Score | ADAC / ÖAMTC overall grade | Price |
|---|---|---|---|
| Maxi-Cosi Pebble S + FamilyFix STop score | 8.8 | 1.8 (ADAC/ÖAMTC 05/2025) | €330 |
| Cybex Sirona TiThis product | 7.5 | 2.5 (ADAC/ÖAMTC 05/2026) | €480 |
| Category average8 products analysed | 7.9 | — | — |
FAQ
Frequently asked questions
Is Cybex's L.S.P. side impact protection worth paying for?
Side-impact protection is mandatory under R129 and has been since 2013 — every i-Size seat has passed a side-impact crash test. L.S.P. is Cybex's implementation of a required function, and its "up to 25% force reduction" figure comes from Cybex's own internal testing rather than independent verification. What you should compare between seats is the ADAC safety sub-score, which is measured independently. Here that is 2.1 — the same as the €149 Graco.
How long can I keep a child seat?
ADAC gives this seat an 8-year usable life under normal use, which is a useful concrete figure. Plastics embrittle through UV exposure and heat cycling in a parked car, so a seat that looks fine may not perform as it did when new. That is also the core argument against buying second-hand: you cannot verify a seat's crash history, and an invisibly stressed shell can fail.
From the same ranking
Other products in Best i-Size Car Seats.
The same protocol, the same key parameter, the same set of sources.
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No. 018.8/ 10
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Joie i-Spin Safe
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Graco Turn2Me DLX i-Size R129
The value finding of this research: €149 for a rotating 40–105 cm seat with identical ADAC…