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How Fast Will The Pros Bike Tomorrow?

Predictions for how fast some of the top pros will bike at the 2015 Ironman World Championship.

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Ryan Cooper, the co-founder and chief scientist of Best Bike Split, uses an intensive set of data points to predict how fast an athlete will bike on a certain race course. Taking things into account such as power, course topography, weather conditions and aerodynamics, Best Bike Split has had some impressive results predicting bike times—and also for giving athletes a power plan for their respective races.

For tomorrow’s Ironman World Championship, Cooper took a look at a few of the top cyclists and made his predictions—with a bit of weather and tactical context. Read more about Best Bike Split here, and check back after the race and see how close the predictions came to the actual split!


“This year, the current forecast will be fairly typical,” Cooper says. “Riders will face crosswind on the Queen K, which will turn to a headwind on the start of the climb, but that will return to a crosswind as they descend Hawi. A slight tailwind will push athletes for the last 20 miles.”


“With more men at the front, it will take a big effort to get away,” he says. “This will take a group of athletes working together to pull off. If stronger riders are willing to work together, it could come down to a select group off the bike. The move will likely have to be made during the section at the turnaround at Hawi. A rider could make the break in the crosswind, then keep the gap with the tailwind on the way back.”

“Amongst the women, the tactics do not play as much into the ride. With a smaller group of select women, they tend to be more spread out during the bike and ride their own races rather than match the efforts of other like the men. “

Predictions: Men

Sebastian Kienle
Predicted split: 4:21
“Kienle will likely have the fastest bike of the day. How well he swims will be a key factor if he wants to repeat.”

Jan Frodeno
Predicted split: 4:22
“Frodeno is much more aerodynamic than last year.”

Joe Skipper (biked a 4:10 at Ironman Texas in May)
Predicted split: 4:23
“Skipper put out over 300 watts during IM Texas, but Kona is a harder course.”

Lionel Sanders
Predicted split: 4:26
“Sanders likely has the highest power output of all the riders, but his aerodynamics have not been optimized as much as the other riders. He could likely go faster, but he would have nothing left for the run.”

Ben Hoffman
Predicted split: 4:31
“On similar power to last year, Hoffman will go a little faster this year.”

Predictions: Women

Daniela Ryf
Predicted split: 4:52
“This number assumes Ryf holds back a bit in order to have fresher legs for the run.”

Rachel Joyce
Predicted split: 4:58
“Joyce will likely be just a little bit slower than she was last year.”

Caroline Steffen
Predicted split: 5:01
“Steffen will be close to her time of last year with similar power.”

Meredith Kessler
Predicted split: 5:00
“As always, Kessler will be consistent and be right at the 5-hour mark.”

 More Kona Coverage.

Video: 4X World Champion Mirinda Carfrae Makes Her Picks for 70.3 Chattanooga

Carfrae and former pro Patrick Mckeon break down the iconic course in Chattanooga, who looks good for the pro women's race, and their predictions for how the day will play out.