From the Easy Racers forum

I finally found the fairing tests info that were sent to me by Karl
Abbe of ZZip Designs.

One of the tests was conducted by Gardner Martin and his
brother Walter, using a 10 % grade hill that was about 2/10ths
of a mile long (coasting,no pedaling). AVG max speeds reached:
No fairing: 45 mph
ZZipper bubble fairing: 46.3
Tear Drop fairing 47.6
Wind Wrap fairing 48.8
Super ZZipper fairing 50
SZ with body sock 52.6

In another test conducted by R.R.Parks in La Jolla, California,
using a 6-7 % grade hill that was 1.4 miles long (pedaling at
~ 15-17 mph until reaching the top of the hill, then coasting),
the Tear Drop performed signifcantly better than the SZ.
Max speeds reached on individual runs:
No fairing 33.4 mph
Bubble fairing 36.1, 38.8, 39.1, 38.7
Super ZZipper 36.8, 38.0
Tear Drop fairing 40.1, 39.8, 40.5, 40.7
Body Sock not tested