I've been using Steve Hogg's "hands-off" test to determine my saddle fore/aft. (Incidentally, that seems to put me within a few mm of KOP.) While fooling with my fit, I discovered that if I raise my saddle 5 mm from my current height -- which seems to be the most efficient (power/speed), and is within a couple mm of heel-on-pedal -- I have to move the saddle 10 mm further rearward in order to past the HO test. Is that normal? Does that mean that I went too high with the saddle? Or, could it mean I SHOULD have it 5 mm higher and 10 mm further rearward?

Can you describe the hands-off test, or give a link? I was just looking for it on SH's site, and it's not popping up.

Are you talking about pedaling with your hands on the bars and then letting go of the bars to see if you have to work hard to "float" over the bars to maintaining the torso position, or if you slide forward?

Yes, I'm talking about that. Here's the link, if it works:

https://www.stevehoggbikefitting.com...or-road-bikes/

Seems right to me. The straighter your legs are, the more your hips will be free to tip forward. As long as you keep the distance from saddle to crank constant as you move the saddle rearward.

One thing that concerns me about that method is that the tilt of the saddle and saddle shape can have a big influence on the feeling of falling forward and how much weight is put on your hands.

Here's the link for adjusting saddle height
https://www.stevehoggbikefitting.com...ard-can-it-be/

Pure speculation, but I would think the changes to muscle recruitment caused by raising or lowering a saddle could cause the need for saddle set-back adjustment. Further speculation would be that for different people, and with different saddle height starting points, you would see different necessary adjustments to saddle setback. So, for one person raising the saddle might result in a need to increase setback, for another it might result in a need to do nothing or decrease setback, all because of different saddle height starting points and different body development.

Of course, speculation is cheap.

I am skeptical since no-hands riding has relatively little to do with the way we normally ride. Unless you normally ride sitting up. Personally I'd prefer to have the bike fitted specifically to how I ride, depending on whatever my objectives were.

Off topic but I have the same objection to Hogg's out-of-the-seat balance reasoning.

Agreed, bikes should be set up for the kind of riding you do and who you are. I do think, though, that there is some use in understanding that, on a typical road bike, moving the saddle aft can reduce the weight supported by the shoulders, arms and hands. That doesn't determine a particular outcome, but can help with fitting and with specific physical issues if one has them.

I think you are misunderstanding the test. It is not a test to see if you can sit up and ride with no hands, it is a test to see if you can take your hands off the bars, while riding in the drops, and still maintain the same posture, the same posture you would have while riding int he drops, without falling over. This give you a more stable position on the bike with less pressure on your hands.

If your seat is in the proper position, you will also not slide forward on the seat while pedaling harder. I had issues with a Brooks. I had to run it tilted up which cause some pain. I can now run it level and do not slide forward at all. I also have zero pain. His method works well. It is a method a lot of fitters use actually. Sheldon Brown advocated its use as well.

I understand it - I just don't agree. I think it's one of those things that superficially sound reasonable, gains wide acceptance, but doesn't hold up to scrutiny.

Fair enough.

Okay, please tell us your method, because when I squat down my butt goes out to the back to counter balance me so I don't fall over. If you try to bend down at the knees without sticking your backside out, you will fall over. The method is said from a physics standpoint.

Now, this is assuming your goal is to be balanced on the bike with not too much weight on your hands. What I like about Steve Hogg is that he adjusts for different people's individual flexibility and other issues.

How do you set your seat setback?

Trial and error, over the course of varied rides.

Balance while crouching is less relevant, because we mostly sit on the saddle rather than hover above it. Try this: hang your feet down, relaxed completely off the pedals, and see how much weight you have on your hands. This should show you that fore/aft of the seat has very little to do with the weight balance of your torso. Core muscles are affected by the angle.

I really don't understand your thought process. We sit bent forward with our hands on the hoods most of the time. To be able to do that for an extended period of time with not too much weight on our hands helps with our comfort and helps prevent injury. Getting it right also means you won't be sliding forward onto your soft parts, also helping prevent injury.

His test, actually it isn't his test, it is a test many use, is not done while hovering over the seat, you are sitting on the seat while doing it. I'm not sure where you get that. The results are repeatable and relevant to how we ride on a bicycle.

Trial and error can work fine for a rider, but a fitter needs to be able to do better than trial an error. It helps to know the outcome you want to achieve, and know the physics, physiology and mechanics involved so you can achieve your outcome. For proper positioning on a bicycle, you want a position that enables you to be comfortably balanced on the bike, with not too much weight on your hands, and one that enables you to pedal efficiently. There are different levels of each, comfort and efficiency, for different purposes. A touring bike rider may emphasis comfort and give up a bit of efficiency, while a racer will give up some comfort for better efficiency and power. Both however need to be properly positioned on the bike to prevent injury and offer some level of comfort. Your test of hanging your legs down doesn't really show anything because by doing that you are altering the weight balance, your legs are no longer pushing, so they are hanging down acting as counter weights which removes some weight from your hands. You are simply changing the balance which does nothing to mimic what you are doing while riding. The balance test is done while actually pedaling, which is very relevant to what you do while on the bicycle, we pedal. It is simply physics.

The important thing for you, is that you have found a good position on your bicycle. You did it though trial and error, and that is fine, but a fitter cannot do that, they are being paid often to correct a problem, and no one wants to pay someone to simply apply trial and error fixes until something works.

I didn't want to hijack his thread but since you sort of ask here, I'll explain that part.

By hanging your legs down loosely and feeling for yourself how much weight your hands are holding, you'll realize that all of the difference from moving the seat back is from support of the muscles around your midsection. Almost none of it is from balance, or from the physical mechanics of leverage. I say "almost" because a small bit (like 2 or 3 percent) shifts due to the longer lever arm if you move back and straighten your arms. But that's an insignificant amount compared to the weight you feel on your hands.

The legs hanging down remove them from the equation, so that you can understand the balance of the torso, between the seat and the bars. The only time that's not relevant is if you're hovering over the seat. All of that weight that you'll feel has to be taken up by your core, after you brace your feet on the pedals.

So moving the seat back does not mechanically change the weight on your hands. You have to brace your feet for that, and for that reason the real effect of moving the seat back is in changing the angle of the hips and lower back. It is physiological, not physics. Certain angles may make it easier to hold your torso up, but it's not because of a change in the actual weight balance. You're changing how the muscles react, using reach and torso angles.

It makes a difference, because what if the rider says that moving the seat back didn't help? You think it has to, because it's a mechanical law (tho it's not) that there's less weight on his hands. Then what, move it back more? In reality, perhaps it didn't help him because he doesn't have the core strength to hold up at the aggressive angle. He needs to sit at a higher angle. Or maybe his back is bowed and he fatigues, and a longer reach would help him. You can't get to that by using a faulty physics formula.

Not a hijack as far as I can tell. I too have been thinking about this for quite a while. I first ran across this "move the saddle back for balance" thing about a year ago. I have a couple bikes where weight on my hands was tiring over long distances, so I moved the saddles back. It worked perfectly. So there's that.

The thing is, you do the test for balance while pedaling normally on the flat at your usual cruising speed. The rule is simply that you shouldn't slide forward on the saddle with the weight off your hands. That means that the torque created by the friction of your shorts against the saddle surface is the same as or greater than the additional torque created by removing the support for your torso and arms.

I think we all know that, no matter how perfectly we try to pedal circles, there's a net downward force pushing on the pedals. The further back our butt, the more torque to hold our torso up we generate about our butt. Were our feet directly under our butt, there would be zero torque. So it's not the angle of hips and back, it's simply the distance of the butt behind the BB.

But of course it takes some core strength to hold our torso in position with no weight on our hands. We don't realize it, but we usually use this core strength to reduce the weight on our hands all the time. It's simple to test this on the bike. Pedaling along normally, straighten your back and stiffen your core and you'll feel less weight on your hands. However no amount of core strength will enable one to take the weight completely off the bars if one then slides forward on the saddle.

The slightly odd thing here is that the coefficient of friction between saddle and shorts must play a part, but I haven't noticed a difference depending on whether my saddle is greasy or not or what shorts I wear.

Doesn't make any sense to me. You're pedaling just as hard during each test of saddle height? I'm guessing that when you raise your saddle, you're taking some of the weight off your feet, which you see as reduced power in the higher position. I'd go for the most powerful position and adjust everything to suit that. One thing I notice is that the greatest quad power is created between knee at 100° and almost straight, while the greatest ham power is created with the knee not so straight. So I feel more power at the bottom of the stroke with my knee bent a little. I like heel just barely touching the pedal, no gap. OTOH, I don't but many other people pedal toe-down and will use a higher saddle position.

This is roughly how I see things. When we pedal, we push down on the pedal, which by the laws of physics results in a force being pushed back up on our feet. This force, transmitted up the body through bone, muscle and joint, can help support the torso, and thereby reduce the forces through the arms and hands. The further back the saddle from the pedal, the greater the lever arm and the more support (torque, in CFB's words) our torso receives from the feet. Also note that the higher the pedaling forces, the higher the support to the torso from pedaling.

At the same time, physiology should play a role. If we have weak muscles for transferring the force exerted on our feet by the pedals, the torso may receive less support from our pedaling forces than it otherwise might. Similarly if the muscles are at angles that don't allow them to work as effectively. So, a weak core might mean we don't get as much benefit from a rearward move of the saddle. So, I think physiology is also a part of it.

I suspect that there is more detail than I've described above (eg there are dynamic issues as our legs are moving masses that are constantly undergoing acceleration and deceleration, and our centre of gravity plays a role), but I believe the above is the gist of part of the story. If one draws a diagram showing the forces acting on the body from the bicycle, one starts to see how things play out.

This also means that the analogy to the "balance" we create by moving our butts back when we are standing on the ground and lean forward is not really a correct analogy. I think it is more that we have three points of contact with the bike and the vertical and horizontal forces must balance each other (if the legs are not pedalling, the forces would simply have to add to zero, but it is a bit more complicated than that). When I think in terms of balance and saddle setback, I think in terms of the body/torso seated on the saddle trying to fall forward and the arms and legs suppling balancing forces/torques to support the body/torso.

Getting back to OP's issue, I think the saddle height *could* affect setback requirements because of the physiological aspect (muscles at different angles, etc). I wouldn't guess as much of a role as OP describes, though.