I’ll start this week’s analyses with Ironman UK. A mid-sized race with the standard 40 Kona slots on offer to age groupers. While it’s been hosted in Bolton for a decade this year’s race saw large changes to the bike course. The new course has had a major impact on results, slowing an already slow Ironman further.
2018 results have been excluded from amalgamated data due to the shortening of the bike course last year. Other variations in the Bolton course remain as they were not as significant.
It’s quite clear that the new bike course has had a large impact on race results. Comparing with the previous 10 years of racing in Bolton shows a roughly 30 minute slowing of the distribution from front to back. This pushes many more athletes closer to the bike course cut off than before. Swim and run distributions don’t vary too much. the run is a little slower, possibly a knock on effect from the longer bike. Naturally the overall distribution is slower for this year’s race too.
Given the size of the shift and the much slower bike median I thought I’d compare distributions with a couple of other races at the slow end of the Ironman Calendar. The new Bolton bike course trends slower than either the Wales or Lanzarote courses. Lanzarote is faster at the front of the race which may reflect the field that it draws. The welsh distribution trend about 20 minutes faster than the new UK bike course. It’s worth remembering we’re looking at one year of data for the new course, so we can’t say exactly how representative these results will prove to be.
We do see an increase in DNF rates from this years race. Again the fault lies with the bike where the rate shot up into double figures. Potentially much of this comes from athletes being pushed outside of the cutoff time on the longer course, certainly there is a lot more weight towards the tail of the bike distribution. It’s hard to say how much of this is the case and while the course is slower, cut off times were standard.
Comparing the age group medians reiterates the pattern of the distribution. A significantly slower bike median across age groups. Run medians are slightly slower, but not as consistently across age divisions.
Ironman UK largely draws a local crowd with a small number of other nationalities racing. The Kona slots look to be spread a little more widely though.
Tracking the times for specific age group positions shows how Ironman UK has been quite a variable race over the years. 2019 does push towards the slowest times, but this varies with size of division and also position within the division. At the very front of the race the change is often much smaller and times aren’t so far from previous years. Further back in the age groups and the impact is larger. We can also see how much faster 2018’s short course was in comparison.
Based on the athlete list I’ve calculated the Kona slot allocation and from that the automatic qualifying times in each age group. Final allocation might vary slightly and roll down will impact the qualifying times. You can compare this with other races on my Kona qualification page.
Finally the top twenty within each age group. The main trend is slower than average times, but there are variations. Age group winners are generally closer to the race average and some smaller age groups trend much closer to average. There are also instances where we see the slowest times for Bolton in the top twenty, but that’s not universally the case. Overall the new course makes Bolton a slower race.
You can access a spreadsheet of the full results from Ironman UK 2019 on my Google Drive.