In 2012, a 41-year-old Lance Armstrong did the Ironman 70.3 Hawaii (Honu) bike course in 2:01:46 on his way to winning the event. The Honu bike course is, basically, the hardest part of the IM Kona bike course, the wind and heat were horrible that year, and LA was well past his prime. I think any number of superstud pro-tour guys could break four hours doing the Kona course as part of a relay.
The wind and heat were bad that year (2012)…but across the board…times were fast on the bike and overall. The wind wasn’t as strong in 2013…but was in a more unfavorable direction. Fastest bikes split in 2013 was somewhere around 2:14 (Crowie). Multiple guys rode under 2:14 the year Lance did it…including a local age grouper. I think Greg Bennett rode 2:08 when he finished “second” to Lance. Bennett was also about 11 minutes faster overall than Crowie’s winning time in 2013. Just to give you perspective on how fast the day was when Lance raced. Course records were shattered that day.