Originally Posted by chimivee
I actually measured those two last night. The race-cut small was 18", pit-to-pit. The race-cut medium was 19.5", pit-to-pit. So, the medium seems close to the Champion size chart ("M=40"), while the small does not ("S=38"). The jerseys we're going with are raglan, so that gives you more fudge room in the shoulders.
I grabbed the jerseys from my car on my lunch. I more carefully measured the jerseys and have some updates to the previous numbers...
Mens Race-Cut and Club-Cut S/S Jersey measurements from armpit seam to armpit seam, with fabric laid flat, but not stretched:
S=18.5" --> ~37" chest
M=19.5" --> ~39" chest
L=20.5" --> ~41" chest
XL=21.5" --> ~43" chest
This seems closer to Champion's size chart, with my measurements being 1" less in the corresponding chest size. It seems that Champion's chart is for a perfect, snug fit. Depending on how form fitting you want it, if your chest is more than 1" over the chest sizes above, you may want to go up a size - especially if you wear bib shorts + base layer. (ie: if you're a 40" chest, go with a Large). It's a good guess that the other sizes (XS, XXL, XXXL) would follow the same pattern.
So, recommend sizing based on chest size:
34"-36" = XS
36"-38" = S
38"-40" = M
40"-42" = L
42"-44" = XL
44"-46" = XXL
46"-48" = XXL
YOUR MILEAGE MAY VARY!