Perhaps I fear that with too detailed a plan, I'll get overly concerned (especially when tired) about deviations from the plan and that the concern will do more damage to my ride than a lack of planning. Or maybe I just don't want to see just how slow I ride enshrined in Excel glory.
So for what it's worth (bring your own salt grains), here's my approach to a 1200km event (I'm up to 13 finishes):
- Try to maintain 20kph (including stops) during the day.
- This is easy to calculate, even when tired.
- Keep stops short enough to keep on that schedule.
- That gives me 6 hours in 24 for rest.
- 18 hours x 20kph = 360km or 24 hours of brevet time.
- 5 hours rest instead allows me to start with an hour in the bank.
- Don't panic if falling behind.
- I assume a shorter sleep break can fix.
- Be cognizant of the 10 hours extra time on return.
- Forgetting this can induce unnecessary panic (as it did on my DNF).
- Ok to settle for 15kph (including stops) during days 3-4.
- Anything better than the 20kph/15kph is gravy. Stop for ice cream.
- Did I mention already? Don't panic.
Looking over this, I can see why I almost always finish in about the same time (83-87 hours). My very few shorter times have generally come when I've only had 2 sleep breaks instead of 3.