NO UNDERCLOSETS!!!!
No chaffing, no ouchy seams (Nanci, at least you've found seamless), no goofy undie lines, just no!
It'll placate the wild woman in you.
My chest is a little on the larger side and my choice is Moving Comfort, it's so individual. Title 9 does have great descriptions but I started out buying local, so I could try stuff on. I went to a running center 'cause I figured if a bra could hold the girls in while jogging it'd be fine with biking. Still, I did have some trouble finding the bra sizes, not just sm, med and lg.
And get on, ride, have fun. You might be a little wobbly at first but with practice you'll be riding a straight line in no time.
Know your hand signals and the rules of the road and enjoy yourself. Welcome to bike riding, glad you could join us!
I used to have an open mind but my brains kept falling out.