My friend who does tons of tri's every year says that drafting is MOST DEFINITELY NOT allowed on the bike. You can't really avoid it on the swim portion, but apparently most events are pretty closely patrolled for drafting violations on the bike. She told me one time what the allowable distance is on the bike, but I can't remember what it was. Blaine (my husband) did a tri with her just two years ago (the Wildflower in central CA) and she did the swim and the run and he did the bike. He said everyone was very good and no one tried to draft off of anyone.

However, that said, a couple of weeks ago Beth (my tri friend) and I were out riding together and we went past (going the opposite direction) her tri team that were out for a training ride, and they were in a huge paceline. There were like 30 of them, I think. So, I guess the rules don't apply for training!!