Originally Posted by Wilfred Laurier

i used to agree
but maybe it is because i am getting older and mellower
and realizing that there could possibly be some things i might not know
but i think any bike designed to be ridden almost exclusively on pavement or other hard and generally smooth surfaces
can be a road bike

mentioned above are flat bar road bikes
which i would have called hybrids a few years ago
are road bikes because they are bikes designed to be ridden almost exclusively on road
the only difference between some flat bar road bikes and a road sport or touring bike
is the handlebars

and if we let the handlebar shape be a deciding factor
and the bike needs to have drop bars
time trial and tri bikes are obviously road bikes
but most dont fit your definition

i guess what i am saying is that
i am starting to think that any bike with skinny and or slick tires
is a road bike
some are just not quite as good as others for certain things
for various reasons