"Experts"

[dcama5]

Originally Posted by martl

I disagree that the average person should be "rare". About 85% of the general population is close enough to the "average person" for cures to work, and epecially so for body geometry etc.
But it seems that 85% of the cycling general public is somehow a member of the other 15%. don't we all like to feel special

martl, not your fault, but I think you misunderstood what Chris was saying. He might better have worded it differently, but he is right.

I worked also in healthcare, retiring in Sept. 2022, at 70 years old, as clinical manager of respiratory care and pulmonary diagnostics at Winchester Med. Ctr. after 30 plus years at WMC. I stuck in there for the pandemic with my office dead center of adult ICU, but retired when the pandemic was over. It's a whole 'nuther story about the nightmare of the pandemic spikes.

As you point out, around 85% of people are average. However, very few are the perfect average. At every anatomic and physiologic point (thousands) we are either average or not. For any person to hit the average at all points is rare. I knew a guy with 3 kidneys, another with a 3rd nipple, and I was told by an ophthalmologist that I have the retinas of an albino. All 3 of us are average but none are the perfect average due to these anamolies.

I think Chris means in prescribing as well as bicycle fit, it makes sense to start with the perfect average, but adjust accordingly.

Dave

[Chris]

Originally Posted by dcama5

martl, not your fault, but I think you misunderstood what Chris was saying. He might better have worded it differently, but he is right.

I worked also in healthcare, retiring in Sept. 2022, at 70 years old, as clinical manager of respiratory care and pulmonary diagnostics at Winchester Med. Ctr. after 30 plus years at WMC. I stuck in there for the pandemic with my office dead center of adult ICU, but retired when the pandemic was over. It's a whole 'nuther story about the nightmare of the pandemic spikes.

As you point out, around 85% of people are average. However, very few are the perfect average. At every anatomic and physiologic point (thousands) we are either average or not. For any person to hit the average at all points is rare. I knew a guy with 3 kidneys, another with a 3rd nipple, and I was told by an ophthalmologist that I have the retinas of an albino. All 3 of us are average but none are the perfect average due to these anamolies.

I think Chris means in prescribing as well as bicycle fit, it makes sense to start with the perfect average, but adjust accordingly.

Dave

Yes. What he said.

[BobbyJones]

Originally Posted by martl

I disagree that the average person should be "rare". About 85% of the general population is close enough to the "average person" for cures to work, and epecially so for body geometry etc.
But it seems that 85% of the cycling general public is somehow a member of the other 15%. don't we all like to feel special

This is what makes someone a cyclist vs someone who rides a bike!

[spoonrobot]

Originally Posted by bicycletricycle

I see very few “to the best of our knowledges”


We have very limited, possibly no access to truth. This means our “truths” will always turn out wrong or at least incomplete.

Nobody needs to be blamed for that.

The problem is when people are misled or bullied by overconfident “experts”. We should all recognize the limits of our own knowledge and knowledge in general

A reminder, 65 psi 700x35 tires are no slower than 120 psi 23s. We were all
amazingly wrong.

The fact that brings us all back down to Earth: at what point in time would you be able to make this statement and have it be a broadly true statement?

I know it wasn't true in the recent past because I went out and bought the fastest 700cx35 tires I could find, and they were significantly slower than regular high-level 700cx23 tires.

So, it apparently wasn't true in 2014, or 2004, or 1994. So 2019? 2021?

Is it broadly true today?

Does this heuristic apply to anything else?

For example, at what point does bicycle geometry (and the ergonomics of the average cycling population) change such that KOPS no longer applies, if it ever did?

The point is not to nitpick, but to understand that looking back with the technology we have today as well as the iterative experimentation - almost always carried out by others! Have you done your rolldown testing and quantified the results for upload to the HiveMind today? - makes it seem like "we" are so much smarter than everyone that came before. However, engaging with the past time periods, at their level of technology and understanding, often makes it clear we would be able to do little better.

If you had to rewrite this book, today - how do you think it would be received in 50 years?

[spoonrobot]

"Knees and ankles absolutely need to be covered below 60°f or long-term damage will result"

Still hearing this one IRL when I show up to race in Feb with bare legs.

[benb]

Originally Posted by spoonrobot

"Knees and ankles absolutely need to be covered below 60°f or long-term damage will result"

Still hearing this one IRL when I show up to race in Feb with bare legs.

This one always blows me away.

I see so many riders that think 55 degrees means booties + thermal tights + winter cycling jacket, etc.. it is a light switch for some people, full winter or full summer. It was in the mid 50s yesterday and I wore shorts and arm warmers and was slightly cold at first and then warmed up, just about everyone I saw was dressed how I dress for 40 degrees.

I have like 4-5 different getups I go through and 5 degrees changes what I wear. I find being overdressed much more miserable than slightly underdressed.

[bicycletricycle]

To be clear, I am also skeptical about the 35 result. I have no idea what the ideal tire size / pressure / construction is for rolling on smooth roads and it seems like nobody does right now.

I wonder how people can be getting such different results with such a seemingly simple question.

Cycling is not the only pursuit to be plagues with such difficulties, the "replication crisis" in the sciences shows that even the professionals are having some problems with what they think they know.

I don't think we are any smarter than people who came before. I think we mostly just go around in circles.

Originally Posted by spoonrobot

The fact that brings us all back down to Earth: at what point in time would you be able to make this statement and have it be a broadly true statement?

I know it wasn't true in the recent past because I went out and bought the fastest 700cx35 tires I could find, and they were significantly slower than regular high-level 700cx23 tires.

So, it apparently wasn't true in 2014, or 2004, or 1994. So 2019? 2021?

Is it broadly true today?

Does this heuristic apply to anything else?

For example, at what point does bicycle geometry (and the ergonomics of the average cycling population) change such that KOPS no longer applies, if it ever did?

The point is not to nitpick, but to understand that looking back with the technology we have today as well as the iterative experimentation - almost always carried out by others! Have you done your rolldown testing and quantified the results for upload to the HiveMind today? - makes it seem like "we" are so much smarter than everyone that came before. However, engaging with the past time periods, at their level of technology and understanding, often makes it clear we would be able to do little better.

If you had to rewrite this book, today - how do you think it would be received in 50 years?

[benb]

I find you can't really separate tires from where you ride.

Fact of the matter IMO is the roads where I live are not the same as they were 20 years ago. They have gotten dramatically worse.

Stuff gets repaved but it seems slow and the specific routes I like to ride due to avoiding car traffic sure seem to have gotten a lot worse, lots of places you need to stop pedaling, level the pedals, and almost get into "MTB attack position" if you don't have big tires.

Not potholes, 25-50' x 10' sections where the entire road is a minefield of 100 potholes that go down to different layers of the road and it feels a little sketchy to ride all the way out to the double yellow to go around it.

[bicycletricycle]

The roads argument is interesting but some of these big tires are better results are on very smooth surfaces.

Originally Posted by benb

I find you can't really separate tires from where you ride.

Fact of the matter IMO is the roads where I live are not the same as they were 20 years ago. They have gotten dramatically worse.

Stuff gets repaved but it seems slow and the specific routes I like to ride due to avoiding car traffic sure seem to have gotten a lot worse, lots of places you need to stop pedaling, level the pedals, and almost get into "MTB attack position" if you don't have big tires.

Not potholes, 25-50' x 10' sections where the entire road is a minefield of 100 potholes that go down to different layers of the road and it feels a little sketchy to ride all the way out to the double yellow to go around it.

[EB]

Originally Posted by bicycletricycle

the "replication crisis" in the sciences shows that even the professionals are having some problems with what they think they know.

Most of the so-called replication crisis is in the social sciences, such as experimental psych.

[bicycletricycle]

Originally Posted by EB

Most of the so-called replication crisis is in the social sciences, such as experimental psych.

Yes, but not all. So called hard sciences have problems as well.

More importantly, I would say that all the things that people actually care about are deep in the replication crisis.

Not technically part of the replication crisis but none the less interesting to me is the mystery of the changing standard KG weights (IPK). Some gain weight, some loose weight, we think we know some reasons but not all the reasons. In the end we gave up trying to figure it out and redifined the KG to avoid the unstable weight problem.

seems like a cop out solution to me.

https://en.wikipedia.org/wiki/Intern...f_the_Kilogram

[Mark McM]

Originally Posted by spoonrobot

The fact that brings us all back down to Earth: at what point in time would you be able to make this statement and have it be a broadly true statement?

I know it wasn't true in the recent past because I went out and bought the fastest 700cx35 tires I could find, and they were significantly slower than regular high-level 700cx23 tires.

So, it apparently wasn't true in 2014, or 2004, or 1994. So 2019? 2021?

Is it broadly true today?

It is often the case that a truth can not be summed up in a simple statement that covers all conditions, but instead a true statement has many conditions, presumptions, and assumptions for it to be true. In the case of the rolling resistance of 32mm tires vs. 23mm tires, it depends on many variables, including surface conditions. pressures, loads, construction and materials, etc.

So, if we hold the environment conditions constant, including a road that is representative of typical paved roads, and loads typical of single bicycles, and pressures typical to those used by the average cyclist, can we still say that a typical 32mm tire rolls faster than a typical 23mm tire? Maybe, maybe not. In the past, it was assumed that someone who bought a 23mm tire preferred low weight and rolling resistance over durability and robustness, and that they would be riding on smooth surfaces so needed little tread depth, so 23mm tires were typically built with flexible high thread count casings and thin treads. At the same time, it was assumed that someone who bought a 32mm tire preferred durability and longevity over weight and rolling resistance, and would be riding on looser surfaces, so 32mm tires were typically made with thick, stiff tread cords and deep high durometer treads with grooves and knobs for traction on loose surfaces. This meant that in the past, a typical 32mm tire did not roll as well as a 23m tire, as least on smooth pavement.

But what of today? With the acceptance of wider tires by people looking for performance, manufacturers are making 32mm tires with flexible high thread count casings and thin treads. And these tires can indeed roll with less resistance than otherwise similar 23mm tires in many cases.

[bicycletricycle]

Amazing we can't say for sure on this. When I think about the ideal way to test this I start to get an idea of why this is actually hard to know, but still, if we knew anything about cycling I would have thought we knew this.

Will we know? I would love to see a max effort test on this.

Drum tests for the tires
Real world Aero with those pitot tube set ups
Computer CFD for theoretical aero
Real world roll down tests
Real world constant power tests
etc.

Would they correlate? Even F1 can have correlations problems with wind tunnel vs real world.

Originally Posted by Mark McM

So, if we hold the environment conditions constant, including a road that is representative of typical paved roads, and loads typical of single bicycles, and pressures typical to those used by the average cyclist, can we still say that a typical 32mm tire rolls faster than a typical 23mm tire? Maybe, maybe not.

[reuben]

Originally Posted by bicycletricycle

Nope, everyone on 165's now.
...
So, how much of current trendy cycling expertise is also BS?

Well, your statement that everyone is on 165s now is BS. But maybe it's not trendy.

[Bob Ross]

Originally Posted by bicycletricycle

everyone on 165's now.

Originally Posted by reuben

Well, your statement that everyone is on 165s now is BS.

Yeah, I guess I never got that memo.

Crap, does this mean the fashion police are going come confiscate my Hipster Cyclist cred?!?!? Or just my oversized crank arms? Oh, the horror...