Well, FWIW, technically, it starts at 5:55 from Lot K (south end of Bowl) but goes slow enough for the first 5-10 mins, you could probably catch on easy.

It's not just any ol' group ride, either. This is a fast-paced, hard, training ride. Don't worry too much about your speed, though they do average 26+ mph for the 31-miles (10 laps). You can always sit out a lap & catch back on if dropped. But, don't attempt it unless you're very comfortable in fast moving packs.

There are lots of other cyclists that regularly ride at the Bowl, though I'm not privy to the details.