Dedicated aerodynamic bars with dropped section, priced £499
3T developed the bar with a wide range of uses in mind - it has the curve and drop of a conventional road bar, but with the addition of a flattened top section with built in pads, plus the Pi Wing - an aerofoil hand rest. This Pi Wing can either be used like a clip-on or removed or the mounts used for full-on TT extensions - it's a very versatile bar.
As a pure road bar the Zefiro is excellent. It's obviously very stiff and aerodynamic too, so what's not to like? The downside is the weight; even with the Pi Wing removed it still weighs 290g, but with the Pi attached it's over 500g.
That said, the shape of the drop is perfect in my eyes. Just like other 3T bars, there's a tight radius at the top to allow plenty of space on the drops and the ability to get nicely tucked in when really pushing hard. The winged top section does take up a little space when sprinting and it's worth noting that it places the hoods 1cm further forwards.
Using the Pi Wing certainly allowed a good aerodynamic tuck to be obtained with several different hand holds possible too - the forearm pads are a waste of time, as they are just too small.
Zefiro is one of those cutting edge products that slightly misses the mark.
It's a great aero bar for road use, but you've got to be willing to accept the additional weight. Sporting TTs are its natural home, yet it's only a little better than clip-ons. Perhaps it's most useful as a base bar with full TT extensions, to give the best all-round options - but that's hardly a big market. All the same, I'm a fan for flatter road events.