Short answer: no, not with the parts either company sells. An UPPAbaby RumbleSeat mounts to UPPAbaby frames. It will not attach to a CYBEX Gazelle S or eGazelle S without an adapter, and we are designing one.
First, make sure you have a RumbleSeat
This trips people up constantly, so it is worth being precise: UPPAbaby makes two different second seats and they are not interchangeable.
The RumbleSeat is the one that converts a Vista into a double. On a Vista it rides in the lower position and uses the smaller of the frame's two adapter sizes. UPPAbaby ships it with lower adapters in the box.
The Toddler Seat is a different product with a different mount. If that is what you have, see will an UPPAbaby Toddler Seat fit a CYBEX Gazelle S? instead — the adapters do not swap.
Check the label on the seat before you order anything. Getting this wrong means a part that simply will not fit.
What the RumbleSeat is rated for
UPPAbaby rates the RumbleSeat V2+ to 40 lb or 36 inches, whichever comes first. That number matters for an adapter: anything carrying the seat has to clear 40 lb to be worth selling, and a figure above it is meaningless because the seat gives out first.
What we are doing about it
The adapter is in design. It is not shipping yet, and it carries a child, which is a different engineering and safety problem from a basket bracket — we are not going to rush it or quietly reuse the language from a cargo part.
Tell the Fit Finder that you want it and we will email you the day it ships.
What fits a Gazelle S today
• Lower-Slot Basket Adapter — the CYBEX shopping basket in the lower slot, so the seat or carrycot can ride above it.
• YETI Hopper Flip Cooler Mount — a Hopper Flip 8 or 12 carried low, inside the wheelbase.
• Balance Bike & Scooter Holder — a balance bike or a kick scooter carried on the upper side frame tube. Either side on the Gazelle S; the left tube only on the eGazelle S.
See the fit guide, everything we make for CYBEX, or the bassinet pairing if that is what you are moving across.
Before you buy any adapter
Every Stroller House part must come off before the stroller is folded. See installation and safety.
Stroller House is an independent aftermarket brand. We are not affiliated with, sponsored by, authorized by or endorsed by UPPAbaby or CYBEX. Brand and model names identify fitment only — see our trademark and compatibility notice.