What competitors need to know:
Disc brakes are a go.
Following the lead of the International Triathlon Union ITU, who approved the use of disc brakes for competition in 2016, Ironman will allow road and triathlon bikes equipped with disc bikes at all Ironman and 70.3 events.
Cell phones are allowed on the course—kind of.
Two-way communication devices, such as walkie-talkies and cell phones, have long been banned on the race course. It’s been a difficult rule for officials to enforce, especially as more and more athletes use their cell phones for bike/run data or race-day tracking. As a sign of the times, Ironman will now allow cell phones on the course, but that isn’t an open invitation to live-tweet your race: athletes using cell phones in a “distractive manner”—in their words, “making and receiving phone calls, sending and receiving text messages, playing music, using social media, taking photographs and mounting the device to a bike for purposes of using the device like a bike computer.”—will be disqualified.
Read more at “6 Ironman Rule Changes You Should Know About” at Triathlete.com