Thursday, July 31, 2025

Dirty Kitten '25: 5th

My official AARP invitation arrived just 2 days after this race. I'm feeling it.

Dirty Kitten is a 2-day affair. Saturday is for the hitters: the folks who want to race 60 or 80 miles. It has also seen worse weather almost every year. Sunday usually has a more casual vibe, with race options of 40 or 20 miles. Saturday's fields are typically packed; Sunday's rarely exceed 45 riders in any given field.

This year was weird.

The men's 40-mile Sunday race had 93 registrants, almost equal to the *entire* grouping of men's entries for Saturday's fields combined. The women's 40 was close to 30 registrants, putting the Sunday 40 firmly into "biggest race of the weekend". 101 people started. Crazy.

Saturday, though, was even more hampered by weather than usual. The forecast called for crushing heat, as it did 2 years ago. In 2023, the Saturday races saw temps hovering right around 100F. With a similar forecast for this year, organizers sent out a last-minute race reduction that pulled a lap off of everyone's registered distance for Saturday. 80 became 60, and 60 became 40. But then it also rained. Like biblically. The opening climb was marked with deep ruts, the grassy section was underwater, big puddles everywhere, and most worryingly: the descent from the Crusher was purportedly rutted. Lap times were way off from previous years, and folks were reaching out to me Saturday night to warn me about the conditions.

And, of course, it also rained Saturday night after the race.

But I had a brand new rear tire that should be extra grippy, and suddenly that 36T ring up front felt extra validated by the slower lap speeds. And at the starting line, I asked the organizer about the day's conditions, and he said the course had dried out nicely overnight, and that the worst of the ruts were clearly marked.

Alastair and I had a plan to start at the front, punch over the opening climb, form a rotation with any other survivors, leave a cooler in an elevated chair so we could swap bottles after lap 1, and keep things neutral until the 2nd ascent of the Crusher, after which it would be an open race to the end.

Things did not go to plan.

We knew the biggest risk of the day was heat. The race started in fog at 80 degrees, and was forecasted to finish at about 90 degrees with a real-feel well over 100. Alastair struggles mightily in those conditions, so that bottle-swap was the pivotal element of the day's plan.

Unfortunately, while the first half of the plan went great, one rider punched over the first ascent of the Crusher, leaving 5 or 6 of us to chase. We were not a confident group of descenders, either, so by the time we were back on open roads, the guy was way up the road, just barely visible. Instead of a neutral rotation, we were a chase group. Alastair and I were on our limits for the next 3 miles, and I'd already spent entirely too much time in the wind just establishing the group's separation.

When we got to the pit to swap bottles, he was empty. I was able to continue without stopping, but tried to gum up the group a little to buy him time to catch back up. The group was not impressed nor impeded, and suddenly I was also in chase mode, but this time starting to feel chills in the sunshine. I let the 2 attackers from our group go, catching them again briefly for a moment before my body screamed to stop, and then settled into limp-mode with one other rider from our group.

The leader was long gone, the 2 chasers were gone, and this was now a trudge to finish in the top 5.

I never saw Alastair again (until after the race, obvs).

I managed to hold on for dear life with one other guy until after the 2nd Crusher, which--for the first time ever--I successfully climbed twice (woohoo gearing choices!). Once we got into the final sunshine-exposed climb by the farmhouse, the chills came back, and I basically just stopped pedalling. I watched my final companion ride away and just limped to the finish line in 5th place.

It was my slowest ever DK40 at 2:26:58, with my worst finishing position of 5th.

Alastair incredibly did not buckle in the heat, but kept a steady rhythm and came across the line just a few minutes after me for his fastest ever at 2:34:47, and his best finishing position of 6th!

https://www.bikesignup.com/Race/Results/79259#resultSetId-569185

Gearing

I spent the previous posts opining about gearing options, and used this space as a place to openly explore the idea of making the least-expensive change possible on the bike to produce the biggest improvement: a 36T chainring to replace my usual 40T.

I pulled charts of gear-usage from previous editions of Dirty Kitten and Monstercross to examine the amount of time spent at either end of the cassette, along with power distribution across the gears showing that even when I got to the fastest gears, it wasn't really meaningful for keeping power.

My theory was that moving from the 40T to the 36T would roughly adjust the time distribution chart by 1 gear toward the top end, but should reduce the bias at the extremes from 4:26 in the 44 and 0:54 in the 10. I ruled out a 38T chainring as being insufficiently different to make a meaningful change, and could potentially throw me into oddball cadences at the typical cruising speeds on this course.

I'm incredibly happy to say it worked out exactly as I'd hoped. Even with slightly odd course conditions and PR's on some of the flatter segments, the gears got me over the Crusher both laps, and I never had any chain drops. In fact this was the first year I've made it through the entire race without putting a foot down.

The following images show gear usage by time and power. The left side are 2025's race, the right are 2024.





Note the more even distribution of power across the cassette with the 36T chainring, as well, with no dips in the 38 or 11. Power was very low in the 10 this year, but even with the smaller 3.6:1 max gearing, it was really only useful on gentle descents.

What this year's gearing did not do was make the Crusher easy. With ramps reaching 23%, nothing will ever make that thing easy. But it did make it manageable, without taking away from the rest of my race. The heat did that on its own.

https://www.strava.com/activities/15255288036

Want to see the Crusher rip our little grupetto apart? Start at 48 minutes: https://youtu.be/r0Wf1c4B2TY

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