The Event
Chase the Sun is an annual unsupported cycling challenge held on the summer solstice. The goal is to ride from sunrise to sunset on the longest day of the year. No official route, no timing, no medals, no organisational infrastructure. You choose your start point, you plan your route, and you ride until the light is gone.
The UK South route is approximately 205 miles. I set out on June 22, 2024, from sunrise.
What Happened
I knew it would be brutal. I knew it would push me to my limits. What I hadn't fully accounted for was the combination of London's relentless traffic, the navigation demand it imposes, and what that cognitive load does when it sits on top of chronic pain, fatigue, and severe digestive issues.
There is a moment in every endurance challenge where you hit a wall. I've been there before — the point where the body screams to stop but the mind pushes forward. At approximately 80 miles, something was different. I wasn't just tired. I wasn't just hurting. I was mentally drained in a way I hadn't experienced before. The traffic, the navigation stress, the constant fight against my own body had taken everything out of me in those first 80 miles.
I knew what lay ahead: 120 more miles, tougher climbs, more isolation, with nothing left in reserve to manage them safely. I had a choice. Keep pushing and risk serious harm. Or do the one thing I've always struggled with: listen and let go.
I chose to let go.
Not finishing does not mean failing. Sometimes the greatest triumph is knowing when to stop, when to step back, and when to acknowledge that you gave everything you had.
What the DNF Actually Means
For a long time I thought finishing was the only valid definition of success in an event like this. That if I didn't cross the finish line, everything before it meant nothing. That thinking is wrong.
The real victory wasn't getting to the finish. It was getting to the start. Daring to try on a body that most physicians would not have cleared to attempt 205 miles. Recognising that sometimes the most honest thing you can do is say: not today.
Trying and stopping is still braver than never trying at all. Some days you reach the finish line. On other days you learn the lessons that carry you to future ones.
What the DNF Taught the System
The Cognitive Prosthesis failed here not in pain management but in pre-ride planning. The navigation load through central London was not adequately accounted for in the physiological budget. Mental exertion depletes the same reserves as physical exertion. When cognitive load is high from the first mile, it reduces the available capacity for every mile that follows.
This is a data point, not a failure. The Dunwich Dynamo Plus in July 2025 — 148.25 miles, solo, overnight, GI shutdown at mile 64, HRV 17ms at the start — was planned with this lesson incorporated. Urban navigation stress was eliminated from the pre-ride window. The result was different.
Every DNF either teaches something or it doesn't. This one did.
On Honesty in the Ride Log
This page exists because the ride log is a record, not a highlights reel. A DNF at 80 miles of a 205-mile challenge with chronic illness, zero medication, and a GI tract that shuts down mid-effort is not something to hide. It is data. It belongs here alongside every completed ride.
The framework is tested by the rides that don't go to plan as much as by the ones that do.