Slowman! Help? - Nebulus seat angle gets worse after the doctors meddle

Triathlon Forum
1

I address this post to Dan, but invite any input.

In your recent article on seat angle, your statements seem to ring fairly true, that there should be some way to calculate the ACTUAL seat angle using the riders body as opposed to the CURRENT seat angle that uses some arbirtrary number. I hope such a thing could be found. It sure would make fitting a more accurate science. BUT…

It seems that we, the collective slowtwitch community, (well, some of us) are striving towards this special seat angle, perhaps 80 degrees. In fact, there is even scientific documentation that many of us use to defend ourselves in our persuit of the perfect angle. The scientists say that we will perform better at 80 degrees. So we continue to finesse our seat angles and mothods of finding them more accurately so that we can find that nirvana that the scientists say is there.

Your last article adds even more desire to find that angle the right way. But for me, the key question has to be, how did the scientists calculate their 80 degrees. If they clculated using 10cm from the front of the saddle, and say how great 80 degrees are, which is probably closer to 76 degrees the way, matbe we are striving towards the wrong ideal. There should, therefore, be some merit to evaluating the ‘seat-angle-finding-method’ of the scientists who purport to have the “best” seat angle.

Is there any way to find out who did the studies you use, and how they figured angle? Or where their riders were on the seat? Or do we really have enough pros that are successful with steep angles to know that an 80 degree angle as you measure it in your chart is the one we should be shooting for.

I just wanted to wonder out loud to see if this is something you have considered in order to see what bearing ‘scientific studies’ can have on us if we don’t know how the studies were conducted. Or, can we (once you have decided the best way to pinpoint accurate ‘body-seat-post’ angle) re-conduct another huge slowtwitch sponsored study to redefine the best angles using accurately derived angles with well-documented butt-to-saddle relationships? I’ll participate.

Thanks for listening and for feeding all us slowtwitchers with your wonderful data.

2

Are you looking for comfort or a More powerful position ?
.

3

Found the article somewhat ironic since it always seemed obvious to me that true seat angle is only related to the cyclsts centre of pressure. TAt least that’s how I’ve always measured my position.

How do you test that…umm…Either empirically in discussion with athlete or by building into a saddle a pressure sensitive membrane (many are used in biomechanics as insoles in diabetes studies) and pressure map your backside basically!!

Downside is that physiological factors may be beneficially impacted on by positioning (i.e. running easier / aerodynamics better etc…) BUT bike handling will be governed by siginificant shifts in cyclists centre of gravity and weight displacement across both wheels.

Hence why a custom 531 steel frame will always seem better than some fancy carbon big brand with funny stem length and odd seatpost with seat rammed forward :wink:

4

Not to shock you, but there is amazingly little ‘science’ in bicycle design and fit. To keep the answer to your general question simple, to my knowledge, there have been no decent, peer-reviewed biomechanical scientific studies published on the direct relationship between bicycle seat tube (or body hip angle) and long-term submaximal human cycling work output using a good-sized sample of athletes.

NONE.

Not to discount anything Slowman writes or says, almost all the geometry and fit info he presents in his articles is based on his own (considerable) anecdotal experience. There is simply no real science at this time to back him up (and he states this openly in several of his articles).

FYI, I have asked several very knowledgable bicycle experts and historians about the origin of the road bike’s approximate 73 deg. seat tube angle. Several had no idea how it originated, others said it was to allow most riders to keep their knees over the pedal spindle (KOPS) at the 3/9 o’clock crank position (another tradition that is not scientifically verified), and others said it was chosen by manufacturers to make an “aesthetically pleasing” bicycle frame by matching the seat tube angle to the head tube angle (!).

5

Dan,

I am as confused now after reading your article as I was when you first asked me “where on the saddle do you measure for the purposes of determining the seat angle?” My confusion stems from trying to understand why someone would need to create three points in space to form an angle that gives you an arbitrary angle called “seat angle”. What information could this angle possibly provide you with? Can this apparent angle be accurately measured? How can this angle, after being created, relate to an athlete’s performance on a bicycle?

So I tried to research the purpose of why this angle has value to you. Following is my conclusion:

Your first article concludes the search for this angle was to conform to a USA Triathlon ruling. You stated “Yes, this is arbitrary, however you have to pick a spot and that’s the spot I’m now using to measure my seat angles.
One of the reasons for this is that 14cm behind the nose is a spot USA Triathlon uses to determine a specific measure for reasons of rules conformity. It seems therefore appropriate to ask everyone to remember only a single place on the saddle for purposes of measurement.” The USAT rule book states that the “14 centimeters behind the front point of the saddle. “ refers to the front-to-center distance exceptions not the saddle angle.

Saddle angle would be applicable to the rules in Article 5.11 paragraph (c) from USAT rule book: c) A vertical line touching the front most point of the saddle may be no more than 5 centimeters in front of and no more than 15 centimeters behind a vertical line passing through the center of the chain wheel axle, and the cyclist must not have the capability of adjusting the saddle beyond these limits during competition.

I suppose you could create angles from these points, but it must be from the nose of the saddle not 14 cm behind. As you proved, this would also be worthless, since all saddles have different lengths.

Your second article concludes that the search for this apparent angle is to determine an ideal performance position by finding a point on the bike or the body now, which can be used as target from the bottom bracket to create an angle that has some value or benchmark. You share with us that even the best in the world ride as much as 10 degrees apart. That is a pretty broad benchmark in my opinion.

Your science seems to find a conclusion and then create a methodology to prove it.

We should all recognize that there are certain landmarks that have scientific, engineering, medical or biomechanical values for measuring provable principles. We should be careful in creating our own science that doesn’t meet proper protocol in establishing facts.

Dan, your assumptions may be inaccurate. Just because three points in space exist and may be measured doesn’t mean there is any correlation to them that provides any value, performance or otherwise.

Your assumptions were inaccurate when you asked me “where on the saddle do you measure for the purposes of determining the seat angle?".

You must have assumed that I measure the “seat angle”. I don’t. In my opinion it is immeasurable. You need three finite points in space to create an angle and there is no place in space to accurately measure “seat angle”. Therefore, in my practice it doesn’t exist.

You then made an assumption that I haven’t thought this through. You stated: “This tipped me off that even though there are quite a few fairly high-priced and well-schooled bike fitters out there, a lot of them haven’t thought this question through.” This was also inaccurate. I have posted on this forum several times trying to understand this apparent seat angle value. No one has ever provided me with a reason why this angle has validity. It appears that since I didn’t give you the answer that you were looking for, you must have thought that I never gave your query any consideration.

Then again, I shouldn’t assume what you were thinking.

Paul

6

I think we need to decide whether we are trying to fit a rule or a body. For rulemaking purposes why not just specify points on the bike, whether it be 14 cm or something else? For a body, though, I don’t think the bike should enter into the calculation. The “three points in space” should be the balls of your feet (to take into account pedal and cleat height differences), your hip joint and your shoulder joint. Maybe I’m niave, but if your hip angle and shoulder angle are correct I say the bike fits. I can “rotate the triangle” for a more agressive position but the fit doesn’t change. Why not measure “effective seat angle” from the ball of your foot to the ball of your hip?

7

Wow, this is an interesting thread. I’ve scanned through most of and gotten the jist, but I haven’t read Dan’s article on the main forum yet.

Here’s my view on establishing seat tube angle for a given rider: Seat angle is the center of the bike position. All other dimensions are born from it. It is the center of the earth, the axis around which all other positional coordinates are established. Seat angle is dynamic, not static. A rider does not “ride at 80 degrees” or any given seat tube angle for that matter. As the performance parameters of the riding envelope change so does the relative seat tube angle. The reason for this is basic physiology of how muscles perform and fatigue and the effects that cadence, power output per pedal revolution and even surface gradient have on the perceived most efficient point of leverage relative to the bottom bracket (that is, pelvis relative to bottom bracket). Fourteen muscles (not counting muscles with the primary role of stabilization) are actuated to complete one entire pedal cycle on one side of the bike, 28 muscles for both legs. The size, angle of force application, rate of fatigue for each of these muscles is different and that is the accounting for why a person’s optimal relative seat angle does change as their riding performance parameters change along with a large number of variables. Of those fourteen muscles, five are the primary “thrust” muscles located in close proximtiy to the femur bone. These powerful muscles “set” the “real” seat tube angle, or the position of the rider’s pelvis over the bottom bracket then go on to change it as the physiology of those muscles change. No science to bike fit? That is wrong. Bike fit is not “art”. It is science in the very strictest definition of the term “science”. Perhaps the best guys at measuring this process of muscle actuation are the “Wobblenaught” guys who are attaching sensors to the rider’s legs to determine the order and duration of muscle actuation throughout a dynamic pedal stroke, includng on the road in real world environments (gradient, fatigue, changes in gearing, power output, cadence, etc). I woud suggest these are the only guys with a pragmatic, empiracle method of determining a central or neutral beginning orientation for the pelvis of the rider on the bike frm where they then have some degree of migration as their level of fatigue and performance environemtn changes. There is no one “correct” or universally “best” seat tube angle for everyone.

Random thoughts to a degree FWIW.

8

Hey Paul, although I think that there is a lot to be desired with regards to the ‘science’ of bike fit, I think the main intent of Dan’s article is to point out that we can’t really examine the details of bike fit if we are all speaking a different language.

For example, if John Doe says he is riding at a “78 deg.” seat angle and Jill Smith says she is riding at a “74 deg.” seat angle, they may be actually riding at exactly the same hip angle due to absolutely zero standardization to how this supposed seat angle is measured. Some issues that create this high lack of standardization are differently shaped saddles, saddles with hugely different length ‘noses’, saddles with differently shaped and length seat rails, seatposts with highly different or zero or forward ‘setbacks’, bikes that have seat tubes with very unusual shapes, bikes that have straight seat tubes that do not intersect the frame’s BB, companies that choose to measure their ‘seat tube angle’ in an unusual way, etc.

Another common result of this is that ‘JD Fabrications’ says they make a bike frame with a multi-use “75 deg.” seat angle and ‘JS Designs’ says they make a bike frame with a triathlon “78 deg.” seat angle. But in actuality, they may be manufacturing a bike with exactly the same effective seat tube angle, again due to almost no standardization to how this supposed angle is supposed to be measured.

One example of this is Cervelo vs. many other “traditional” road bike builders. Cervelo, according to their published geometry, measure the “seat tube angle” from the center of the BB to the center of the seat clamp at the top of the seat post, relative to a horizontal line (and this is not the same angle as the actual seat tube). “Traditional” road bike frame makers have usually measured the seat tube angle as the actual angle of the seat tube (the frame tube itself) makes relative to a horizontal line. Then, riders usually put on a traditional seat post with around 2 cm. of setback to position the seat.

So a rider sitting in exactly the same way on the same saddle with the same position on the seat rails on a “74 deg.” Cervelo and “74 deg.” traditional road bike with exactly the same seatposts (one can’t use the same posts as Cervelo uses their own proprietary one, but seatposts with exactly the same setback) will put the rider at different positions and hip angles.

I think one reason that no one can seem to agree on a universal standard method of measuring this fairly important frame or body angle is that the “traditional method” (measuring the actual frame tube angle–the angle of the seat tube) is easily confounded by unusual frame designs (i.e., the unusual seat tube on the P3 for one) and unusual seat post designs (zero setback, forward positioning posts, and ‘reversible’ posts like the Cervelo).

So I think that is the problem Dan is trying to address: everyone in the industry seems to be speaking their own language, and some industry folks are not even aware that different languages are being spoken.

9

Interesting reply, Tom. You might want to read Slowman’s article, as it will give you an idea of what the problem is.

Some questions for you:

“Seat angle is the center of the bike position.” — Can you clearly define ‘seat angle’, even ‘dynamic seat angle’? I.e., how exactly do you measure it?

“No science to bike fit? That is wrong. Bike fit is not “art”. It is science in the very strictest definition of the term “science”.” — How do you support this statement? What studies have been done on seat angle (or dynamic seat angle) that have put the examination of this parameter in the realm of science? Please give references to these studies as I would like to find them and educate myself.

“There is no one “correct” or universally “best” seat tube angle for everyone.” — This seems correct, but how do you know this for sure? Have you or anyone ever done a good study to verify this? Has anyone done a study to show that the optimal seat angle is different for everyone? How can one even scientifically determine the best seat angle for one particular person?? Wouldn’t you need a wind tunnel and a sophisticated powermeter to determine the truly optimal seat angle for one particular person? And then, again, how in the heck do you even measure the angle? Everyone seems to do it differently.

10

Perhaps Paul is right. Dan jumps to many conclusions without much scientific merit. I also agree with the poster who says that Dan seems to be trying to let the manufacturers know that some standardization may help everyone involved.

I tend to hope, and the reason I started this thread, is that there should be some sort of way to accurately define or quantify the riders relationship to the bike, that is more accurate than ‘knees over spindles’. Why? Once such a method is determined and can be accurately replicated, and providing that it takes into account the four points in Dan’s latest article…then one could have a starting point for collecting empirical data that just might be of some worth.

For example, lets say we find an accurate way to get ‘Actual body/seat angle’ or ABSA and test several top pros to find that the strongest riders tend to ride with an ABSA of 78-78.5 degrees, while the strongest runners tend towards 80 degrees. Such a test can’t be currently done for the simplest reason that we don’t have a method of calculating these numbers accurately.

We may also find that all riders tend to move in the saddle until their ABSA is right at 75.5 degrees. It wouldn’t happen, but what if?

Maybe we find that riders are so separated over the spectrum of ABSA measurements that we realize we should be more concerned about comfort than other things.

But, we can’t come to conclusions without doing some studies. We can’t do studies until there is a good way to gather data. I applaud Dan for what I interpret to be a concerted effort to derive a worthwhile method of collecting data which may or may not change our sport. For our collective sake, I hope he is on to something. Let’s help him think this thing through, if for nothing else to pave the way for those to come.

11

<<<“No science to bike fit? That is wrong. Bike fit is not “art”. It is science in the very strictest definition of the term “science”.” — How do you support this statement? What studies have been done on seat angle (or dynamic seat angle) that have put the examination of this parameter in the realm of science? Please give references to these studies as I would like to find them and educate myself. >>>

Bike fitting is not a science! If any studies have been done on seat angle or not does not matter to the question of “Is bike fitting a science or not?” - Applying knowledge that has empirical support does not mean that bike fitting is a science.

The bike fitting process aims at solving a specific problem – how do maxmimize the efficiency and effectiveness of a human-machine work-system while considering a number of factors. Each fitting process is a unique process, as it needs to address the characteristics of a particular person. For the process to be science the aim should be the acquisition of new knowledge and the validation of existing knowledge in order to contribute to the body of knowledge relevant to scientific discipline of bike fitting. This is not what Tom Demerely does, despite his observation that 14 muscles are used!

The question is - does the fitting process applies scientific knowledge? To what extent the fitter relies on valid studies in selecting their methodologies? I would argue that bike fitting is not a science, not applied science and despite the fact that one is designing a work-system with explicit performance parameters it is not an engineering discipline either.

Bike fitting is a craft.

Craft
Problem - implementation & evaluation
Type of knowledge - heuristics
Knowledge acquired through - practice (experience and training)
Cost of knowledge acquisition - low

Science
Problem - hypothesis & test
Type of knowledge - theories, models, laws, hypotheses
Knowledge acquired through - scientific enquiry (deduction/ induction)
Cost of knowledge acquisition - high (induction) low (deduction)

Engineering
Problem - specification & implementation
Type of knowledge - engineering principles
Knowledge - deduction from scientific knowledge
Cost of knowledge acquisition - high

12

Three good questions, as usual.

Q: “Seat angle is the center of the bike position.” — Can you clearly define ‘seat angle’, even ‘dynamic seat angle’? I.e., how exactly do you measure it?

My A: Seat Angle, Tom’s definition: The angle described by an imaginary line originating at the center of the bottom bracket and extending upward to any number of coordinates subject to the intended use of the angle, i.e. there is **frame **seat tube angle (the static seat tube angle of the bike frame’s seat tube relative to the horizontal), **pelvic **seat tube angle (the angle described when the line ends at the intersection of the femural head as it plugs into the pelvis) and then the dynamic seat to angle, which is the “arc” through which a rider moves fore/aft on the saddle as mission requirments change (i.e. changes in pedal rate, pedal force, etc.). An example of this is: What is the dynamic seat tube angle of a riding climbing out of the saddle? It could be well in excess of 95 or 100 degrees as their pelvis moves forward (such as a Armstrong like climbing posture with hips very far forward at a high, choppy cadence).

I measure this angle using different techniques for each measurement or angle type. Basically, for frame seat tube angle you “flat patch” the bike and make sure the bottom of the wheels are on level ground then just determine the real position of where the center of the bottom brakcet is and then the center of the exit hole for the seatpost is. This is often different than the leading edge of the seatpost, so you have to be careful with this. I like to use a big, long level to put the angle finder against to read the real frame seat tube angle.

Measuring the pelvic angle is tricker since, as soon as the rider begins to pedal, the Pelvic angle then becomes the dynamic angle and will start to change. You can measure it the same way you do the frame, but what is the reason to do this? It will change as soon as the muscular geometry changes as the muscles fatigues. The Wobblenaught guys can probably see this happen. Short of their methodology, other techniques for measuring this may be accurate in a static sense, but probably not of much value the instant the rider begins to pedal.

Q: “No science to bike fit? That is wrong. Bike fit is not “art”. It is science in the very strictest definition of the term “science”.” — How do you support this statement? What studies have been done on seat angle (or dynamic seat angle) that have put the examination of this parameter in the realm of science? Please give references to these studies as I would like to find them and educate myself.

My A: Bike fit is a science because, done correctly, it adheres to the definition of scientific investigation and method:“The observation, identification, description, experimental investigation, and theoretical explanation of phenomena” That directly describes good fitters on-going interaction with fit and positioning.

Just one example of a formally conducted seat tube angle scientific investigation, in the academic sense of the terminology, is the “Garside Study” conducted by Ian Garside and Dominic Doran correctly refered to as “Effects of Bicycle Frame Ergonomics on Triathlon 10-km Running Performance.” as published in the June 2000 issue of the *Journal of Sports Sciences. *This is most easily referenced as paraphrased in Dan Empfield’s FIST fitting manual and is just one example of a study conducted using normally accepted scientific techniques as defined above. There are others but I don;t know them off the top of my desk.

Q. “There is no one “correct” or universally “best” seat tube angle for everyone.” — This seems correct, but how do you know this for sure?

My A: I know this for sure because the dimensions of each person’s skeleton and the physiological configuration of the attached musculature is unique. Those, along with additional mechnical factors, are the determining factors in establishing seat tube angle. Given that this set of variables alone is arguably nearly infinite, then the interpolations/extrapolations of that data to determine the appropriate (optimal) seat tube angle is likely also infinite to a commensurate degree.

Q. Have you or anyone ever done a good study to verify this?

A. I haven’t ever conducted a formal study of this, and I’m not certain that anyone has. Realisitcally, I would suggest it isn’t necessary. I mean, do we all agree people come in different sizes? Do we all agree that seat tube angle (whatever type of seat tube angle you are discussing) is predominantly related to body dimensions? Given those two assumptions (facts?) I would suggest such an investigation would be largely redundant, i.e., there isn’t much need to do a doctoral disertation on the existence of gravity or the theory that the earth is round.

Q. Has anyone done a study to show that the optimal seat angle is different for everyone?

A. I don’t know. I think they have. Dan and Gerard may know the answer to this question.

Q. How can one even scientifically determine the best seat angle for one particular person??

A. This is the “meat” of your question. I’m not telling how I do it because it is a proprietary service that I sell and I don’t want it borrowed, stolen, perverted, misunderstood and defamed ad nauseum. But I will offer this insight: The technique I use is no better and no worse than any other system in current use and the same as some with some additions. That said, the best technique is still not that great. It could be much better. Again, based on what I know about it, I will argue the best system is a Wobblenaught style system where there is some empiracle protocol and apparatus for reading what the muscles are doing and then making changes and observing those changes. In the strictest sense of the scientific, empiracle way to observe, change and evaluate seat tube angle and its effect on performance, I will suggest theirs is the best. They are the only ones using a device to measure muscle actuation and observe it while pedalling.

Q. Wouldn’t you need a wind tunnel and a sophisticated powermeter to determine the truly optimal seat angle for one particular person?

A. I guess that depends. Do you want a strictly biomechanical answer or a more realistic answer as applicable to the road environment? My thoughts are that once the biomechanical parameters are established and optimized, then the aerodynamic optimizations can be considered PROVIDED they do not compormise the biomechnical prinicples. There has to be some interplay between these two principles (aerodynamic and biomechanical) and a third factor that influences bike handling in the real world: i.e. the best Computrainer position will likely not be good on the road since it is probably not optimized for aerodynamics or steering and stability and sublties lie reaching for a water bottle while pedalling.

Q. And then, again, how in the heck do you even measure the angle? Everyone seems to do it differently.

A. Well, I did read Dan’s article on figuring out if a bike fitter is any good and I am almost entirely in agreement with it. I also agree that there are some people calling themselves “bike fitters” out there who need substantial additional education and experience before they shoulder the responsibility of fitting someone to a $1500 + bike system. Since bike fit is the new “in thing” a lot of guys are cropping up saying “I am a bike fitter!” and also buying a host of entertaining theater props to support their performance. There are some good theater props out there too: Adjustable bikes and stems that look very impressive and laser apparatus with computer screens and all manner of quasi-medical looking gadgets that enhance a “bike fitters” credibility or at least perceived credibility. I would suggest, especially right now, the majority of it is theater. That is the answer to your question of why everyone seems to do it differently- or at least a part of the answer. Another part of the answer is that there are several ways to establish such a measurement. As long as the person doing the measurement produces accurate, precise, repeatable data and understands the significance of it for their fitting protocol then I would suggest their version is acceptable. That I am aware of, there is no consensus though.

Whew. I hope that answers your (good) questions.

Happy New Year!

13

Ok, I generally agree.

But the question is, as you say, does the fitting process apply scientific knowledge? I say, at present, there is no decent of body of scientific knowledge to even try to apply, only various opinions, a little anecdotal knowledge, a lot of copying, and a lot of (mostly) baseless ‘tradition’…

14

Oh, I don’t agree with that. Especially the tradition part.

15

Wow, quite a reply, Tom.

Well, I think you are doing a great job in trying to get people as comfortable (and therefore efficient) on their chosen bikes, given the highly limited base of knowledge that currently exists ‘out there’–no doubt about that. But much more scientific scrutiny is needed. Whether that ever happens, of course, is another story entirely.

On a sidenote, the ‘Garside Study’ (by Ian Garside and Dominic Doran on the “Effects of Bicycle Frame Ergonomics on Triathlon 10k Running Performance”) did not address the direct relationship between bicycle seat tube (or body hip angle) and long-term submaximal human cycling work output at all, only its effect on possible post-cycling 10k performance (and, if I recall correctly, the study used a very small sample of athletes).

16

If you fit me and another fitter fits me - would I be in the same position?

The answer is - no.
This is because what you do is a craft. You may involve some scientific knowledge but your own interpretation of it is tuned and optimized via your experience which you may only pass to your colleagues. This is not a scientific process. This is what a skilled craftman does.

17

“But much more scientific scrutiny is needed.”

Absolutely no question about this.

18

Tom,

You have vast experience in fitting people to bikes and you are considered as one of the best in the industry. I can see that claiming that the process is scientific has commercial benefits. However, Greg is correct in arguing that the process involves more tradition than science. And there is nothing wrong with that. If a person’s performance (could also be comfort or injury prevention) improves due to your consultation and if they perceive that improvement as worth your fees then your are providing a good service.

But the methodologies, techniques and methods that you are using are far from being in a mature state where rigours studies have clearly shown the correlation between each dimension that you observe or tune and an external performance factor.

19

I would agree with IronPluto that bike fitting is a craft. And “that there is nothing wrong with that”. I would never consider myself a scientist. I am a craftsman. I may use scientific principles in exercising my craft, but that doesn’t make me a scientist.

I am still interested in understanding why Dan is trying to identify this apparent seat angle. Greg, I understand your explanation of the industry’s lack of standardization. I struggle with it all the time when I try to design a bike for an athlete that is using a stock geometry. Many geometry charts that you find on manufacturer’s websites prove to be inaccurate. But as you noted: ” So I think that is the problem Dan is trying to address”, I didn’t read that was the reason for identifying the apparent seat angle in any of Dan’s articles.

We will just have to wait to see what Dan has to say. I wouldn’t want to put words in his mouth.

20

I think I clearly stated a good reason, (maybe similar to Dan’s, maybe not) why defining such points and angles is worthwhile. Read above if you missed it, but in short:

There is little (some would say none at all) scientific study showing the effects of different seat angles on cycling performance.

We would like to have such studies.

We can’t have these studies until an empirical way if found to consistently replicate a given seat angle with any single rider on any bike.

Once this can happen, studies can be done and science can be used to find hypothesis and theories and perhaps even proof that certain angles provide better results.

If this is the case, and such angles are found, and are easily replicatable; then this science will simplify the ‘craft’ of fitting.

For example: If science can prove that 80 degrees really will give the best triathlon run performance, and 80 degrees is measured through a concise point. Then any fitter can apply the formula and; yes, going to two different fitter (who subscribed to this theory) would yield the exact same results.

I assert that Dan seeks to define the angles so that others can quantitatively study how those very narrowly defined angles affect us under real world conditions. He seeks to make the craft of fitting more of a science, or at least get some science behind it.

Does this reasoning sound erroneous? Where is Dan anyway? Doesn’t he have better things to do on New Years Eve than dinner, and dancing and partying? :slight_smile: Hapy New Years to All.