It’s the night before the big dance – and athletes in Kona are currently having their penultimate night’s sleep before the women’s Ironman World Championships in Kona and we’re of the opinion that course records will probably fall. Historical precedent tells us that it’s the first year where it’s within the realms of possibility that the winner of the women’s race in Kona this year will be faster than the male winner from 2014!

A lot has been made of the weather forecast in the triathlon media this year at Kona, it’s going to be pretty windy with the average wind speed picking up to around 30kph in the back half of the bike course and the famous crosswinds on the Hawi descents are looking like they’ll make an appearance.

Even though the wind on course is pretty high, the wImpact on the day is between 0 and 1.5% – this is pretty low and means athletes will only be a maximum of 1.5% slower when compared to a completely neutral day. In 2018 conditions were similar when the bike course record was broken by Daniella Ryf.

Using a system mass of 72kg (that’s bike and rider) and reported rolling resistance and drivetrain losses values that represent the best of the best – a rider with a cda of around 0.19 will need between 210W and 215W to break the course record. This will be a power to weight of around 3.5W/kg.

If you want to play around with the forecast for the Ironman World Championships bike course, click here.