jambon

How do yall set saddle fore aft?

like what's your logic or what feel do you look for when riding the bike ?

Should my knees be right over the pedal spindle like on top of the cranks or should I be sitting behind the crank pushing it in front of me?

I find the Kops thing confusing in that the plumb line dropped from the knee is dropped from different points of the knee depending on which source your reading from i.e some say front of knee , others down through center of the joint , others the bony protrusion at front , so depending on what I go by it could vary by up to 3-4 centimeters.

The balance method doesn't work for me either , I can support myself with hands off the bar leaning forward no matter where i put the saddle.

Jeff Neese

Kops is mostly irrelevant. There are a lot of other factors that go into a proper fit and if you get everything dialed in, your knees will probably be about over the spindle anyway, on a traditional frame. But there's no need to adjust for that specifically. Saddle fore-aft will affect your reach and therefore your body angle, but then you've got frame size and handlebar height to account for also.

The Myth of KOPS

jambon

So......What your saying is that the forward back plain relationship of the knee to the pedal spindle does not matter at all , except in extremes which your unlikely to find yourself in unless the overall fit is very poor?

ofajen

With steady, medium effort pedaling, I move the saddle back to make sure that I don’t feel like I’m sliding forward on the saddle when I lift my hands.

Otto

Iride01 

Just move it a little and ride it some. What feels good for short rides may not feel good for really long rides. Same for tilt.

You don't need us!

Jeff Neese

You're talking about saddle tilt, not fore-aft movement on the rails, aren't you?

Jeff Neese

Pretty much. If the bike fits you well and it's adjusted to you, your knee will be approximately over the spindle anyway, on a traditional frame. Obviously a recumbent or pedal-forward bike is different.

rm -rf

Edit--I didn't see that you mentioned lifting your hands. Think about this "sliding forward" test when you try it again. Sounds like your fit is pretty good already.

This bike fitter video is interesting and useful. Essentially, you want a saddle position where you aren't sliding forward if you lift your hands off the bars. That keeps the arms from having to push you back all the time.
The first part to the 4:00 mark is an interesting discussion and debunking of "knee over pedal", but since it's not relevant to fitting, it can be skipped.

How to set saddle fore aft position 3:55 mark.

This helped me make a slight adjustment that was a nice improvement.

My bike fit
I have the saddle quite level where my seat bones are, not overall level. The nose is actually slightly higher.

I have the bars set just an inch below the top of the saddle. I have a very comfortable position in the drops this way. And the hoods are still fine. Oh, it's so nice to have usable drops when I'm going fast, in headwinds, and especially on very rough roads or fast downhills. There's much more control in the drops.

My hoods are slightly sloped upward, so my wrists are straight while using the hoods. The drops are angled just like the fitter video.

Yeah!

PeteHski

So let's forget about KOPS, because as you have already rightly noted it's not even a well defined parameter you can actually measure. Which exact bit of your knee "needs" to be directly over the pedal spindle and why does this even matter anyway? Nobody seems to know.

The balance method sounds plausible in theory, but like you I can support myself with the saddle anywhere I like. I've tried this many times on my Kickr Bike and never found an obvious solution.

So my current method is to put the saddle right in the middle of the rails and then just forget about it!

Carbonfiberboy 

With most folks, dropping the plumb bob from the bony protrusion below the kneecap works. The balance test is if one slides forward on a level saddle when taking hands off the bars - move saddle back. In general, your hands should simply be light on the bars, not supporting your torso weight. That's the all-day riding posture. Otherwise your arms get tired unless you're one of those 100 pushups a day folks. Even then, your hands and wrists can get tired. However if your arms and hands are fine with a 6 or so hour bike ride with KOPS as I've described here, you're golden. don't worry about it. Going hard, you'll probably scoot forward on the saddle. On long climbs, you might scoot back. Or not.

I think another interesting thing to look at is your standing location vs. saddle. I think if you're standing and maybe very slightly pulling back on the bars, no or little weight on your hands, the backs of your hams should just brush the saddle nose on a normal length saddle.

The reason KOPS mostly works is that most folks' femur length has something to do with their CG location when they lean forward. Doesn't work for folks with unusually long or short legs. KOPS works for me. Even though I have relatively short legs, I wind up with a 30mm setback post and the saddle most of the way back on the rails. Something to do with my frame's seatpost, its angle and the fact that it doesn't land on the CL of the BB - carbon bike..

PeteHski

Wouldn't your CofG location have far more to do with the weight of your upper body than anything to do with your femur length? I just don't see a meaningful correlation there. Even that bony protrusion below the kneecap is quite variable among individuals, as one outspoken Ozzy fitter has pointed out. So for me KOPS is just some arbitrary point of reference that may or may not happen to coincide with your ideal fore-aft position.

I totally agree about hands being light on the bars. But for me personally that doesn't nail down my fore-aft position very precisely. I have a light upper body, so I've never really had a problem supporting it in any realistic saddle position. Goodness knows how many times I've messed around with saddle fore-aft position, only to conclude that I'm not very sensitive to it.

Carbonfiberboy 

There's usually a relationship between torso and femur length. Most of us are quite scalable, i.e. the posited relationship exists.

cyclezen

Not being contentious...
But If KOPS ain't somethin, then what is? There's always this load called " A Lot of Other Factors" - what are these factors?

if KOPS is not 'precise' enough, what is? the whole 'Balance the torso while pedaling under some load' certainly is hugely variable and certainly way less precise KOPS.
... all this then leads into saddle height and where you put the cleat position...
how much lean for the torso ?
There really is nothing currently suggested which isn;t totally anecdotal.
for many decades KOPS has been the start point, with mostly good results... other methods also seem to work for some.
So, OP, there currently isn;t any definitive on what you're asking; so one must start with something... maybe just starting with the saddle mid-rail ?
one can certainly spend the money to do position/power testing, or one can 'experiment' on their own (not always a successful methodology).
But then you have been a BFer since 2014, and likely riding some, during that period; and have already made some decisions...
so this likely another 'winter' thread ?
Ride On
Yuri

PeteHski

What I'm saying is that someone with a large (or just relatively fat) upper body build vs slight build will have much more upper body weight to support when leaning forward over the bike, regardless of their leg geometry. Torso and leg length appear to be all over the shop anyway. Plenty of people with short legs, long torsos and vice versa. It's hardly worth generalising. Add that to people having different bony knee protrusions and the KOPS argument doesn't stand up to much scrutiny. But pro-fitters are pretty unanimous on ignoring KOPS these days.

PeteHski

KOPS is just an arbitrary point i.e. the bony protusion from your knee directly above the spindle. This arbitrary point might precisely position your saddle fore-aft, but it doesn't mean it will precisely put you in the optimum fore-aft position. The balance method at least ensures that you are not likely to be positioned too far forward.

tomato coupe

Yes, KOP gives you a somewhat arbitrary starting point, but so does the balance method. Strict adherence to either as the ultimate arbiter of saddle position is misguided.

PeteHski

Exactly. Although the balance method at least has an actual goal in mind (i.e. finding an individual's unique balance point) which intrinsically takes account of many of the variables involved e.g. the weight of your torso and your back angle. KOPS just presumes a single generic human model, a one-size-fits-all solution. Sort of reminds me a bit of the max heart rate 220-age formula. Maybe accurate as an overall average across a large population, but pretty useless for any individual due to the wide range of variance.

PeteHski

Coming back to the OP's original question, I just try to get a feeling of natural balance on my bike. When I'm riding along at tempo, do I feel like I'm propping myself up on my arms? Maybe I'm too far forward? Or does the steering feel a bit vague and nervous? Maybe I'm sat too far rearward. Am I constantly looking to shuffle forward or backward on the saddle? Or am I content sat right in the sweet spot of the saddle? These are the sort of things I think about when setting up my bike. I don't even measure KOPS or saddle setback, except maybe the latter just to get a reference if I change my bike. As I mentioned earlier, I'm not particularly sensitive to saddle fore-aft anyway.

cyclezen

Actually KOPS is not as arbitrary as one might think - as many think...
KOPS does take into account one major factor which affects both muscle engagement and hip angle/power delivery.
KOPS adjusts for femur length, which in the pedal stroke is the factor which greatly affects and determines muscle engagement, hip angle and power delivery, when assuming a 'competitive' position for road cycling. The range of position needed is greater than what might be indicated - but then 'On the Rivet' was and is a very common condition for many races and sections. Same for 'out of the saddle' and having your butt nailed to the saddleback.
KOPS came about as an anecdotal method to what was yet to be shown by science, as a good balance position for varied riding conditions.
I don't really have any investment in KOPS, but it does work for a starting point for competitive road cyclists who must start with some indicated point.
Whatever 'balance method used might be good for, it's in no way addresses the above mentions factors.
It does help riders who are carrying a large mass in their torso - generally less concern for most competitive cyclists.
Personally, "Balance Method' is as good as putting the saddle mid-rail.
Ride On
Yuri

qwaalodge

I tried both KOPS and Balance at least two months each.

I end up being faster on balance method due to greatly improved comfort and possibly more aerodynamic position.

I had to reduce stem length on my bike though because my balance position is significantly behind KOPS position. The balance position made me feel overstretched so I went for a shorter stem.

tomato coupe

I'm glad you discovered what works best for you.

PeteHski

I don't really understand your argument about femur length and KOPS. Neither does Keith Bontrager and it's probably fair to say he has researched it more than most. Quotes from his article linked earlier:-

"The KOPS method is arbitrary because it relies on the gravitational orientation of a plumb bob. The direction of gravitational force has no bearing on the rider's ability to pedal"

"What is important is that I have not noticed any specific correlation between seat angle and my customers' femur bone length. I am reasonably certain that none exists"

Now if KOPS happens to work for you, then great. But I don't see any genuine scientific basis for it.

cyclezen

Right, there is no scientific evidence for KOPS, nor is there scientific evidence for any other 'method'. So consideration of all is possible, equally.
If you don;t understand the relationship of femur length, KOPS and ultimately cycling, then it's worth the process of thinking about it.
K. Bontrager - great guy, added a lot to bike equipment ideas, especially mtb. very glad he's been doing that - but he's never been involved in any scientific study on bike position.
so, his comments are 'opinion', from possibly his observation and thoughts, but more than any other thoughts? debatable.
There have been attempts at scientifc studies for saddle position and fore-aft.
Here are just 2 examples:
https://ojs.ub.uni-konstanz.de/cpa/a...view/4430/4120 (this one actually downloads a PDF - best I can determine is it's not infectious or virus containing... But download at your risk)
https://www.sciencedirect.com/scienc...66337621000093
This 2nd one is mighty 'scientific' and bites a big mouthful, funny in many ways, and ultimately completely ignores fore-aft in it's summary ... meaning, they're didn;t want to wrassle that Bar... LOL!
If therez some Sigh-ENz evidence for 'balance', I'd like to see that. Same for 'Mid-rail'.
Tomato Coupe was nicely succinct - "Yes, KOP gives you a somewhat arbitrary starting point, but so does the balance method. Strict adherence to either as the ultimate arbiter of saddle position is misguided."
I cede to that plume of terse wisdom.
Ride on
Yuri

Carbonfiberboy 

The bolded part is fun because that's the thing that the balance method relies on. The idea of starting with KOPS has nothing to do with pedaling mechanics, only with balance. It's just an easy way to get the rider close to being in balance, no more, no less. There's really nothing to argue about. Simple inspection should be enough to convince anyone that there's no scientific method for determining this balance point. It depends on the rider's proportions, weight distribution, pedaling style, and surely other variables which are also impossible to measure by any means other than riding one's bike.

PeteHski

Well if KOPS was a generic attempt at finding a rider's CofG balance point (which I don't believe it is) then you might as well just use the balance method anyway, because that intrinsically takes all the various inter-related parameters you mentioned into account. Ultimately it's a pretty subjective process, which I think we can agree on. It's hard these days to find a professional fitter who pays any regard to KOPS, although I'm sure there are a few diehards out there.