I was having a great ride, averaging 20 MPH with the front B group, until they dropped me when they ran a red light with traffic, which I wouldn't do. I stopped and picked up the second B group. I pulled much of the way around S 40 Drive, but dropped them on the last climb to Mason. I didn't want to continue by myself so I stopped to pick them up again at S 40 and Mason. As we pulled away southbound on Mason I got up to about 18 MPH and without warning my front wheel caught a crack in the road and took me down instantly. I slid for 10-15 feet before coming to a stop. By the time I picked myself up, inspected the bike and got my dropped chain back on, the third B group caught up with us. I brushed myself off and resumed the ride, but had to work my way through some slower cyclists for a bit before getting up to the front again. Up to the point of my crash I was at 20+ MPH, but I still managed to finish the ride (including Marshall Rd. climb at 18.7 MPH. My bike is fine. I scuffed my bar tape, and scratched my rear thru axle. The worst part is I tore the edge of my nice Fizik Arione Carbon saddle and ruined my favorite pair of expensive L.G. bibs. I am A-OK though, and had my fastest Alpine ride yet. Afterwards, several people told me I really need to start with the A group. I enjoy that compliment very much. It was worth the pain I have yet to suffer for it.