The best in aero anyway... by a healthy margin. I've not seen a cross-section of this rim but from the description it sounds like a big fat oval... ie similar to the Zipp Firecrest concept. It seems like a very unaero shape to me... but I guess not. The other funny thing is that Zipp and Hed have been at the top of the aero game for many years with their toroidal rim shapes, and now that the patent on that has run out they are making a completely different shape... that is even better. I'm impressed.
They tested the wheels with a 21mm Corsa CX... which makes the results even more surprising, since the Hed is the only one designed for wider tires. They did a sweep from 25 down to zero yaw, and the Hed was the only rim to have flow attachment at 15 deg... which resulted in a drag of only ~30g, compared to 150-200g for all the others. At 10 degrees things tighten up a bit, but the Stinger is still the best... and it's the best at every angle from 0-20.
Wheel, Drag @ 10 deg yaw (front wheel, 30mph)
Vision Trimax Ultimate, 175g
Cole T85 Lite, 160g
Easton EC90 TT, 145g
Bontrager Aeolus 9, 120g
Zipp 808, 110g
Hed Stinger 9, 85g
I see that Zipp has a new Firecrest 808, but this one was the old model.
They tested the wheels with a 21mm Corsa CX... which makes the results even more surprising, since the Hed is the only one designed for wider tires. They did a sweep from 25 down to zero yaw, and the Hed was the only rim to have flow attachment at 15 deg... which resulted in a drag of only ~30g, compared to 150-200g for all the others. At 10 degrees things tighten up a bit, but the Stinger is still the best... and it's the best at every angle from 0-20.
Wheel, Drag @ 10 deg yaw (front wheel, 30mph)
Vision Trimax Ultimate, 175g
Cole T85 Lite, 160g
Easton EC90 TT, 145g
Bontrager Aeolus 9, 120g
Zipp 808, 110g
Hed Stinger 9, 85g
I see that Zipp has a new Firecrest 808, but this one was the old model.