Even though cycling is my strongest one of the three disciplines, I remain amazed at how fast the top triathletes are riding.

The average bike time across Ironman races is 6h18 min which translates to a speed of 17.8 mph or 28.6 km/h. The women cover 112 mi in 6h44 min (or 16.6 mph or 26.7 km/h) and the men in 6h12 min (or 18.1 mph or 29 km/h).

I found out that those times depend significantly on the Age Group and the specific course. So let’s check that in more detail.

METHODOLOGY

I checked all Ironman races from 2019, and I excluded the shortened ones. So the final database consists of 55,123 times from age-groupers and 731 from pros.
A special thanks to Coach Cox, who gathers the results of all Ironman (and Ironman 70.3) events. He made my life easier!

AVERAGE IRONMAN BIKE SPEED PER AGE GROUP

As you can see in the graph below, the average bike speed for the men is around the 18 mph mark for the youngest age groups (or around 6h05min). The highest average bike speed is reached in the age group 35-39 (18.5 mph).

If you want to contend for first place in those age groups, you need to bike 5 mph faster. It doesn’t sound that bad, but keep in mind it is over a 112 mi course! 🙂

Ironman bike speed per age group men

It is a pretty similar situation for the women. They ride at an average speed of 17 mph mark for the youngest age groups (or around 6h35min), and the winners are roughly 4 mph faster.

Ironman bike speed per age group women

AVERAGE IRONMAN BIKE SPEED PER RACE

I find it really interesting how much a course can influence those times. In the graph below, you can see all those races sorted by the fastest bike speed. Ironman Barcelona was the fastest course with an average speed of 20.4 mph for the age groupers and 25 mph for the pros.

Due to their well-known bike course difficulty, IM Wales, Lanzarote, and UK are, without any surprise, the ones with the slowest bike speed. If you want to ride one of those, be ready to spend 7 hours in the saddle on average.

Average Ironman bike speed for the age groups and pro men

Barcelona and Copenhagen were the fastest courses in the women’s races, with an average bike speed of 18.6 and 18.3 mph, respectively (roughly 6 hours).

Average Ironman bike speed for the age groups and pro women

WHAT IS THE BIKE CUT OFF TIME FOR AN IRONMAN?

Most Ironman races have a 10h 30 min cut-off time for the bike. This time limit is based on the triathlete’s own chip time and consists of the swim time, transition 1, and the entire bike portion. Exceeding this time will result in a DNF (Did Not Finish).

This cut-off time can vary a lot per race, check out my article Ironman Time Limits Per Sport And Per Race for more details.

If you enjoyed this analysis, have a look at those two articles which cover the swim and run legs of Ironman races: