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TT riding
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Mostly A or mostly B? also... tail wind.... sit up?


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Re: TT riding [synthetic] [ In reply to ]
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What is the question and what is going on in B?
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Re: TT riding [synthetic] [ In reply to ]
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Sitting up in a tailwind? The vector of the wind parallel to and along your direction of travel must be EXTREMELY large to make sitting up worth it.

How large/fast? If gearing was not an issue, then faster than the speed you would go if you could bike at your max sustained power with zero resistance except tire rolling resistance and hub/drivetrain friction (and that's probably easily in excess of 100mph).

Or, if gearing was a limiting factor, then the speed at which you COMPLETELY spin out your very highest gear and the wind was still pushing hard on your backside (depending your gearing, that could be 60-70+mph).

Otherwise, don't sit up.

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Last edited by: DarkSpeedWorks: May 17, 22 6:32
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Re: TT riding [DarkSpeedWorks] [ In reply to ]
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DarkSpeedWorks wrote:
Sitting up in a tailwind? The vector of the wind parallel to and along your direction of travel must be EXTREMELY large to make sitting up worth it.

How large/fast? If gearing was not an issue, then faster than the speed you would go if you could bike at your max sustained power with zero resistance except tire rolling resistance and hub/drivetrain friction (and that's probably easily in excess of 100mph).

Or, if gearing was a limiting factor, then the speed at which you COMPLETELY spin out your very highest gear and the wind was still pushing hard on your backside (depending your gearing, that could be 60-70+mph).

Otherwise, don't sit up.

Win was about 20mph, goal pace 25. For some reason cannot pump the watts in aero on tail wind, figure sitting up would give 30 more watts to out put, and the sail effect would help. I do 290w into wind and 230 with tail in aero position
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Re: TT riding [synthetic] [ In reply to ]
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Not really how it works. The tailwind needs to exceed your ground speed at target power and in an available gear. Typically, this would be when you have a ripping tailwind and you're going up a grade slow enough that the tailwind is faster than your groundspeed up the steep gradient.

So, up 10% grade at 6mph and 10+mph tailwind........sit up. Up 2% grade at 20+ mph with 10mph tailwind........stay in aero.

It would be a super rare and difficult to ascertain situation of a false flat uphill of some % where your airspeed is high enough to be in aero normally but the tailwind is enough to do something like that. Something that without a Notio with the live wind speed field on a Garmin, you wouldn't know anyway.

Honestly, it's folks "being human". Humans riding long periods of time in a position that isn't exactly an upright endurance bike, maybe need a break once in a while how they're holding themselves.

If someone is "doing that on purpose for aero", it's a highly misguided decision.

Normally you'd be going slow enough uphill with a ripping tailwind to be out of the extensions all together instead of just tilting the helmet up.

Also......ignoring the photo here to give you an example of someone else who does this............fuck Chris Froome, dude's a moron to stare at his TT bike hub all the time up and down up and down. I don't care if he's a TdF winning pro or not. Not every jock in the world is also gifted at the science of their sport. Mash pedals for cash, dunk ball for billions, etc....
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Re: TT riding [burnthesheep] [ In reply to ]
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burnthesheep wrote:

Also......ignoring the photo here to give you an example of someone else who does this............fuck Chris Froome, dude's a moron to stare at his TT bike hub all the time up and down up and down. I don't care if he's a TdF winning pro or not. Not every jock in the world is also gifted at the science of their sport. Mash pedals for cash, dunk ball for billions, etc....

Picture for reference? I assume you are complaining about him looking down climbing up a hill? Fyi my original post is meant in a flat course.
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Re: TT riding [synthetic] [ In reply to ]
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synthetic wrote:
burnthesheep wrote:


Also......ignoring the photo here to give you an example of someone else who does this............fuck Chris Froome, dude's a moron to stare at his TT bike hub all the time up and down up and down. I don't care if he's a TdF winning pro or not. Not every jock in the world is also gifted at the science of their sport. Mash pedals for cash, dunk ball for billions, etc....


Picture for reference? I assume you are complaining about him looking down climbing up a hill? Fyi my original post is meant in a flat course.


It's not that bad, here, but still. I can pace a flat 40k damn near perfect looking at my meter once or twice in the first 3 mi to ease into the effort and same again at the u-turn. Dude here looks there that many times in a 25 second video clip. "TT chops" he has as a pro TdF champ and junior TT champ or not, I really really do not understand it.

https://www.youtube.com/watch?v=YxzsYllq_rM


As for your original post meant for a flat course, insufficient gearing, insufficient confidence going that fast, or insufficient understanding of vectors.


With sufficient gearing, the wind is never "pushing" against the tail sticking up from behind. Ever. Unless it is so windy, you couldn't ride a bike anyway.
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Re: TT riding [burnthesheep] [ In reply to ]
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kind of conflicted as what you are trying to say. So which is ideal..... picture A or B for most of the ride?
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Re: TT riding [burnthesheep] [ In reply to ]
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It seems to me that the sit up position would come into play at windspeed somewhat less than bike velocity if: one can generate more power sitting up; the delta more power is greater than the delta more aero drag from sitting up; and the overall impact of the higher sitting up watts is more positive than negative (i.e., the time savings of running the higher sitting up power is less than the subsequent time addition resulting from running that higher sitting up power). I know a first approximation may be that a watt is a watt, but for athletes who have not developed their musculature for aero position, they may be able to recruit more developed muscles for more power sitting up at little cost to the rest of the race.
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Re: TT riding [synthetic] [ In reply to ]
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A every time. A helmet tail sticking up is no good. Maybe slightly faster if you're looking at the head by itself, but that's going to mess up airflow over the rest of the back.
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Re: TT riding [hugoagogo] [ In reply to ]
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hugoagogo wrote:
It seems to me that the sit up position would come into play at windspeed somewhat less than bike velocity if: one can generate more power sitting up; the delta more power is greater than the delta more aero drag from sitting up; and the overall impact of the higher sitting up watts is more positive than negative (i.e., the time savings of running the higher sitting up power is less than the subsequent time addition resulting from running that higher sitting up power). I know a first approximation may be that a watt is a watt, but for athletes who have not developed their musculature for aero position, they may be able to recruit more developed muscles for more power sitting up at little cost to the rest of the race.

and that is what I was thinking

imswimmer328 wrote:
A every time. A helmet tail sticking up is no good. Maybe slightly faster if you're looking at the head by itself, but that's going to mess up airflow over the rest of the back.

this kid is looking down. he just set the course record here in 20k (low 23min) and became pro


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Re: TT riding [synthetic] [ In reply to ]
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Is the tail of his helmet sticking up in the air? Or perhaps is it pointing along his back? You're comparing two fundamentally different positions.
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Re: TT riding [synthetic] [ In reply to ]
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synthetic wrote:
hugoagogo wrote:
It seems to me that the sit up position would come into play at windspeed somewhat less than bike velocity if: one can generate more power sitting up; the delta more power is greater than the delta more aero drag from sitting up; and the overall impact of the higher sitting up watts is more positive than negative (i.e., the time savings of running the higher sitting up power is less than the subsequent time addition resulting from running that higher sitting up power). I know a first approximation may be that a watt is a watt, but for athletes who have not developed their musculature for aero position, they may be able to recruit more developed muscles for more power sitting up at little cost to the rest of the race.

and that is what I was thinking

imswimmer328 wrote:
A every time. A helmet tail sticking up is no good. Maybe slightly faster if you're looking at the head by itself, but that's going to mess up airflow over the rest of the back.

this kid is looking down. he just set the course record here in 20k (low 23min) and became pro

Really? He appears tucked but looking ahead to me (maybe not way down the road but certainly ahead).
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Re: TT riding [burnthesheep] [ In reply to ]
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burnthesheep wrote:

Also......ignoring the photo here to give you an example of someone else who does this............fuck Chris Froome, dude's a moron to stare at his TT bike hub all the time up and down up and down. I don't care if he's a TdF winning pro or not. Not every jock in the world is also gifted at the science of their sport. Mash pedals for cash, dunk ball for billions, etc....

'Show us on the doll where Froome hurt you.'
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Re: TT riding [synthetic] [ In reply to ]
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synthetic wrote:
this kid is looking down. he just set the course record here in 20k (low 23min) and became pro

Try your argument with a Tempor or a classic Giro Advantage 2. It's different helmet shapes you're looking at. Sometimes to test theories you have to accentuate or bloat the feature in question in a more extreme way to see an implication. Whole reason a Tempor wasn't that great when released was the "en vogue" bike fits of the time simply didn't work with it. Now in some TT and track stuff, it does.

If it's tails, make the tail a lot longer and the other helmet a lot shorter. Like Giro Adv 2 versus a Bambino with both sticking the back end up. It becomes obvious. And also obvious it depends on the fit style. Ganna runs a Bambino and not a Mistral for a reason.

You can do the same thing with things like different socks you might not be able to measure. You can't grow larger legs necessarily but you could increase the test speed.
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Re: TT riding [burnthesheep] [ In reply to ]
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burnthesheep wrote:
synthetic wrote:
this kid is looking down. he just set the course record here in 20k (low 23min) and became pro


Try your argument with a Tempor or a classic Giro Advantage 2. It's different helmet shapes you're looking at. Sometimes to test theories you have to accentuate or bloat the feature in question in a more extreme way to see an implication. Whole reason a Tempor wasn't that great when released was the "en vogue" bike fits of the time simply didn't work with it. Now in some TT and track stuff, it does.

If it's tails, make the tail a lot longer and the other helmet a lot shorter. Like Giro Adv 2 versus a Bambino with both sticking the back end up. It becomes obvious. And also obvious it depends on the fit style. Ganna runs a Bambino and not a Mistral for a reason.

You can do the same thing with things like different socks you might not be able to measure. You can't grow larger legs necessarily but you could increase the test speed.

i have giro advantage 2. so basically looking down will not work like these more modern helmets in the pictures I posted
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Re: TT riding [synthetic] [ In reply to ]
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 me and my set up below. Arms fall asleep after 40 min. think I need better ski bends for that issue.


Last edited by: synthetic: May 20, 22 12:07
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Re: TT riding [synthetic] [ In reply to ]
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another view of the fast kid

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