The humble gilet. Know more commonly, as the wind vest. No cycling wardrobe should be missing one.
With the unpredictable nature of Richmond weather, you can easily experience 20+ degree swings in temperatures during rides as short as two hours. A light weight gilet is a key piece of kit in my arsenal against chilly rides.
My personal favorite is the AVIP Wind Vest
from POC. The fabric is incredibly lightweight which makes it very easy to crumple and stow in my jersey pocket. A few reflective points on the back are nice as well.
Just thick enough to keep the chill off my chest, this vest is literally so light I don't even notice it's in my pocket. I rarely leave my house without this piece either on my body or stowed just in case the temperature drops.
Oh, and I did mention it's light, right? Hold on tight if you're removing it on a windy day.