what is proper bike etiquette for passing slower riders who are all kitted up in lycra and racing bikes?

I live in an area that has a lot of race bikers and they never wave back when I pass them on my 30 pound monstercross bike. I have something called Primary Familial and Congenital Polycythemia which is a genetic disorder tha gives me retardedly high red blood cell count so its really easy for me to just fly by all these guys.

Is there some kind of special hand wave? I say "hi, nice day for a ride" without any labored breath as I pass them and see them huffing and wheezing. Are they just out of breath and thats why they don't say hi back?