-
To roughly the size of a can of beans. Not the very smallest but pretty good. I’m a XS in Rapha (mainly proteam) and an XS for the HotPack.
Having said that, it’s a good few years old. I think when I was looking for a commuting jacket (which ended with the MTR) I tried on a few Sportful ones and their sizing has changed. IIRC way smaller, don’t think I could even get into an XS. I’ve not changed size...
I’ve got a Sportful HotPack NoRain as my pack small for potentially wet weekend rides - love it.