I realize there may not be a true "answer" to this, and some of what I have to say makes no sense, but since I'm not exactly the brightest tool in the refrigerator, it may just be that there is something obvious that I'm overlooking. I have this O/C thing about constantly adjusting my bike fit (which seems to get worse as the years go by).
No matter how I adjust it, it always feels like something is not right.
There were over a 1,000 changes since 2008, in the last 5 years averaging over 120 changes per year. I've had 6 bike fittings — every one left me LESS comfortable, and slower — with such a variety in positioning, that you'd swear they were for 6 different cyclists! For example, one had a saddle-to-bar reach of 52 cm, another 59 cm! So, I know I won't find an answer there.
The main issue seems to be that I need to keep changing my position in order to stay in the same (relative) position. Here's what I mean: With all my "fit fooling," I've determined the most efficient (and comfortable) saddle position is pretty much "heel-on-pedal" for height, and "knee-over-pedal-spindle" for setback, give or take a few mm. (I actually use the "hands-off"/"balance" test to set that, but that also puts me KOPS, so I just call it that.) The thing is, some days I can pass the hands-off test with the saddle tip 8.5cm behind BB, other days I can't pass it unless the saddle tip is 10cm back.
Likewise, some days a saddle height of 79 cm (BB — center of saddle) is HOP, other days it 80cm. (And, yes, I'm using the same bike, pedals, saddle, etc.) Usually, soon after I start a ride, I'm like, "WHAT THE &@%*!?!?!?!", because the position feels so screwed up, it's like I'm on someone else's bike! (Even though the day before, the fit felt perfect.)
So, I spend most of the ride adjusting things, then — usually a mile or two before the end — I finally get it just right. Then, next ride, once again it's "WHAT THE @^#*?!?!?!?!" So, the whole process starts again. (Like a cross between "Breaking Away" and "Groundhog Day.") I also fool with the bar position some, but not nearly as much as the saddle. The only theory I came up with — that my job had something to do with it — didn't pan out. (I'm a mailman who walks 8+ miles a day up and down God-only-knows how many hills and steps).
I was thinking I might need a different position when doing a ride after work than when riding on my day off. Experimented for a while with that, but didn't discover any pattern.
I suppose fitness/fatigue levels may have some affect, but could that result in "to my problem", but wouldn't such big difference in height and fore/aft on a daily basis indicate something PHYSICAL is going on?
If I didn't know better, I'd think my legs randomly grow and shrink at will, or something! Is it possible that I just need a different position on different days? Could it be due to my torso being 10-11cm shorter than normal compared to my legs? Any suggestions appreciated, but, again, I understand if it does not have a clear answer.