Design
The Cocoon is compact, the shortest stroller/trailer tested, with a moderate sized storage space behind the seat. The door has built-in mesh and clear vinyl windows for different kinds of weather, meaning no extra rain covers to buy. In stroller setup, the removable handlebar has a narrow foam rubber grip, making it good for smaller parents but not larger ones. The handlebar and small stroller wheels attach with hitch pins that rattle when it’s in motion, and the trailer arm and jogging wheel attach with a threaded screw—secure but inconvenient if you switch attachments a lot.

Performance
As a stroller, the Cocoon works fine. The handlebar, while narrow, can be adjusted to two heights, and the pneumatic wheels give a smooth ride. The biggest complaint with the Cocoon is as a bike trailer. The axle attachment has a tendency to rotate downward, which tilts the whole stroller forward. Combine that with two kids in the upright seats (and the springiness of the arm itself), and you can end up with riders tilted forward in their seats to the point of falling out if they weren’t strapped in.

Comfort
It isn’t roomy inside the Cocoon, especially for two kids, with little headroom and an upright seat that doesn’t recline. The ride can be pretty bouncy with no shocks. That said, the usual features like inside pockets, big windows and five-point harnesses put it in the middle of the pack as far as passenger comfort.

Convenience
The Cocoon is easy to put together and fold up. It collapses compactly—everything fits inside—and is easy to move and store, though it could use a buckle strap to hold it shut. The only secure lock point is on the axle.

Quality
The base unit itself is solid, but the attachments and the stroller handle are a little on the flimsy side.

Value
The base model only comes with two small stroller wheels. The jogging wheel and bicycle trailer attachments ($70 each) are sold separately.