On Mar 30, 7:29 am, "John Crankshaw" wrote:

Either one have an edge over the other?

The LG has the windscreen accessory. Is that an edge?

TT helmets provide most of their benefit from the way that they smooth
the flow over your back. That means: 1) the drag-minimizing helmet
depends on your position and your ability to hold that position; and
2) looking at the front of a TT helmet may very well be less important
than looking at its side and rear.

Both of those reasons mean that no single TT helmet is the best across
all riders and you can't expect to get the same results that your
buddy gets with his helmet. The only way to know for sure is to test.
It wouldn't surprise me if a helmet that performs well under ideal
conditions doesn't perform nearly so well if the yaw angle changes or
your head or neck droops -- or even if you hand position changes. It
appears that the best way to think about aero drag is to visualize air
flow over the entire body and bike as a single unit, not piece-by-
piece.