If it's a USA Triathlon-sanctioned event, drafting is not allowed. If someone passes you, you have to fall back so there are at least 2 bike lengths between you. Check out the rules at http://www.usatriathlon.org/Rules_Of...rules.htm#5.10 . If you have more questions, you might want to ask the helpful women on the triathlon board http://forums.teamestrogen.com/forumdisplay.php?f=45 .