Krdytkyu

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.

Often, I get on my bike and things feel a little off. I put it down to varying fatigue, stiffness, amount of sleep, mood, stress or a hundred other things. I then try to get get warmed up, then concentrate on good technique and having fun, or, if I really am feeling off, cruising along for a bit then getting a coffee.

It sounds like you have trained yourself to be hypersensitive to feeling 'off', then feel the need to need to mess with the saddle position. Maybe you just are not letting you body actually get used to an reasonably OK position. What you need to do is get the position ballpark right, then just stick with it and let your body get used to and adapt to it. I also wonder if regular stretching would make you feel better on the bike.

I'm not surprised that different fits came up with different positions. Bike fittings are not supposed to find your 'perfect position' - that does not exist. They find a good position for a particular purpose. Different fitters may have had a different idea of what you were trying to achieve. Also, I'm not surprised you were slower after each fitting. Your body was not used to the new position and hence you could produce less poswer.

I would suggest that your issues on the bike might be better resolved off the bike and that you're trying to use bike fit to resolve underlying body issues. Have you ever taken the time to evaluate your core strength? If your fit feels and looks right one day then while riding you feel uncomfortable, then this is likely due to fatigue in your supporting muscles. If you think that this may be the case, then you'll need to start doing some work off the bike to target this weakness.

This can be done with yoga and core strength workouts. I've always preferred to just focus on the compound lifts which will work the core muscles sufficiently to strengthen them for cycling, while also giving your cycling muscles a workout as well. Start off with deadlift and squats then if your legs still feel good while your core is fatigued, you can move on to leg press to get a bit more out of the session.

I don't currently do any gym work, so to maintain my core muscles lately, I've been doing hikes with a lot of vertical metres. Having weight in your backpack can help a lot as well.

In addition to the other answers, I'll add that the way you're doing your fit might be leading you down the wrong path.

There's just no way you can detail everything that goes into your fit processes into an online post.

Given

There were over a 1,000 changes since 2008, in the last 5 years averaging over 120 changes per year.

and

I've had 6 bike fittings

and especially combined with

Could it be due to my torso being 10-11cm shorter than normal compared to my legs?

Yes, I'd think that certainly could be a significant issue, especially for your six bike fittings. You sound like you're way outside the norm that almost all bikes are made for and likely the vast majority of bike fitters have significant experience with.

Nevermind if the fitter uses a cookie-cutter fit "system" that would almost certainly be based on riders with less extreme proportions...

You'd almost certainly break such systems.

I recommend reading this, the best treatise on fitting a bicycle that I know of:

How to Fit a Bicycle

by Peter Jon White

Bicycle fitting is a subject most people find quite mysterious.
Fitting systems with charts and graphs, computer software, measuring
devices and "rules of thumb" make for a lot of confusion. But I
believe it's really quite simple. Bicycle fit involves compromises.
Compromises between comfort and performance, quick acceleration and
handling stability, top speed and "taking in the scenery".

Your body's position on the bike affects how you ride. It affects how
much power you can efficiently deliver to the pedals. It affects how
comfortable you are on the bike. A position that is more comfortable
may not allow you to put as much energy into moving the bike forward
as a less comfortable position might. How do you decide where to
position your body on the bike?

Ask yourself, "What do I want to do with my bike?", "Why am I
riding?". A track sprinter is not the least bit concerned with how
comfortable he is sitting on the bike. During the race, (which may
last for less than a minute), he may only be seated for 5 or 10
seconds. A long distance tourist traveling coast to coast across the
USA might spend 5 to 12 hours a day in the saddle, day after day. He
is probably far more concerned with being comfortable and enjoying the
scenery than with going as fast as he can.

This article relates only to traditional road and cross country
mountain bicycles. I know next to nothing about recumbent bicycles and
have absolutely no advice to offer regarding recumbent fitting. Nor
have I any experience using "aero bars", which allow the rider to rest
his forearms on the handlebars.

...

Read that - all of that - then make some adjustments to your fit, get it where you're OK with it, then let it go for a month.

You have to give your body time to adjust to the new fit.

So tell yourself, "I will not @!%$@ with my fit for a month!" And stick to it. Else you'll just go back into the "repeat" phase of "rinse, lather, repeat".

If you're lucky, you'll forget all about your fit problems by the end of the month and never bother with it again.

I fully agree with this existing answer, but would like to add something:

Maybe get into the routine of doing some stretching and calisthenics before and after the ride (stretching before and afterwards, calisthenics mostly afterwards). That way you would notice that your condition is very different each day and you need to work with that. Don't change the fit each time, it should be somewhere in the middle of the range where your exact optimal values are each day.

For example trying to reach down with your hands while keeping your legs straight (not overextending the knees) is a fairly relevant stretching exercise if you intend to ride in a fairly aero position. If your reach is lower than usual on a day then your position will feel more aero/harder than on a day when you can easily reach down very far.

Similarly if you try a plank then if you can hold it shorter than usual that means your core is fatigued and you can't expect to ride as comfortably as when you are completely recovered.

That way you have some more measurable feedback from your body. And your body isn't asking you to change your fit, it's telling you that you might need to go easy that day (might currently make you feel as if the fit is too athletic), or that you are in great shape (which might make you want a more aero position, but that's not necessary).

Another suggestion for a possibly good habit: Set a date, say once a month, when you are allowed to change the fit. Then stick to never changing it other than on that day. That will force you to choose an average position that should fit you ok no matter you day to day condition.

How old are you?

Age takes a toll on all of us. As we age, things don't recover as well, and our tolerance ranges narrow. What was comfortable one day may be outside your comfort range another day

How heavy are you?

I used to be 20 kilos fatter than now. So getting into a good dropped aero position was difficult because my belly hit my thighs on each pedal stroke. A big meal or lots of water could move the comfortable zone over a bit.

How fit are you? How flexible are you?

These go together - your muscular fitness and how far those muscles can stretch comfortably will define a range of acceptable motion. If your position puts you outside those ranges,

Does your body have a monthly cycle?

The ebb and flow of hormones can truly do a number on your body. Similarly medications, and stimulants like alcohol or caffeine or nicotine can also vary your comfortable position.

So in short, pick an average of all the positions that you've found to be acceptable for a time, and try to simply ride that setup.

I've found that moving back and forth between several different but similar bikes can cause a period of adjustment, whether it be between a roadbike and a MTB, or a compact folder and anything else, or even road bikes of different geometries/styles.