
While shopping for a passenger helmet, I noticed that in many cases the
external dimensions of the helmets were the same from S through XL.  The
difference was the amount of inside padding.

My solution was to buy a large helmet, and construct a removable liner 
from a sheet of .5" closed-cell foam and some satin (glued to the inside
surface).  The result is a reasonably snug fit on my smallest-headed pillion
with the liner in, and a comfortable fit on my largest-headed pillion with
the liner out.  Everyone else gets linered or not by best fit.



-- 