Originally Posted by
wgscott
I am thinking of getting a Wavecel road helmet. My head circumference is squarely in the middle of the overlap region between M and L. I have the L mountain bike version, and it fits fine, but if the medium version would also work, would I be better off with a lighter helmet, or am I simply getting less protection for the same-sized head with the M vs. the L?
You'd certainly be getting less ability to wear a warm cap under your helmet, which may (or may not) matter to you.