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Trails of COVID... dispersion behind a walking person

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Trails of COVID... dispersion behind a walking person

 
Old 12-18-20, 08:08 AM
  #26  
genec
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Originally Posted by livedarklions View Post
No offense, but I don't see how any of this applies to drafting. This is all modeled on an upright average height person at walking speed, not a seated rider traveling at bicycling speed. The assumptions of both the positions and the airflow therefore have no resemblance to riding. I'd say drafting is a bad idea because we don't know whether it's safe, but this has almost no implications for that.
Apparently you have never drafted cyclist that sneezed.
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Old 12-18-20, 11:48 AM
  #27  
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Originally Posted by mstateglfr View Post
If you travel at 20mph, which is a very common pace for enthusiast group rides, you cover 60' in 2 seconds. Based on the picture at the start of this thread, the virus is very much still clumped together at 2 seconds when outside. Perhaps this is why its been difficult for some to let go of the suggestion and instead ride even closer than 60'.
There are a lot of factors at play. To be infected, you need to have a certain number (no one knows how many) of virons that you inhale or otherwise consume in a vulnerable area over a period of time. Given all those factors, you really can't make a lot of conclusions and extrapolate about what is safe and what is not. One means to know what is safe and what is not is contact tracing, and studies have shown that you can be infected at pretty good long distances, but indoors and if you are there for a significant period of time ... I think the latest I saw was as little as 10 minutes and 20 feet away. Outdoor transmission remains rare, let alone outdoor transmission at long distances and with a lot of turbulent flow.

There is no such thing as zero risk, and it is wise to avoid known significant risks. I begged off of a ride with a friend who was exposed to someone with COVID (he later tested negative). But if walking behind someone outdoors and 60 feet away were enough to be infected, I'm pretty sure we would have seen a lot more infections than we've seen. What I've read is pretty clear about what the problem is ... people gathering together indoors with family and friends and in particular during the holidays.
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Old 12-18-20, 11:54 AM
  #28  
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Originally Posted by livedarklions View Post
No offense, but I don't see how any of this applies to drafting. This is all modeled on an upright average height person at walking speed, not a seated rider traveling at bicycling speed. The assumptions of both the positions and the airflow therefore have no resemblance to riding. I'd say drafting is a bad idea because we don't know whether it's safe, but this has almost no implications for that.
May I point out that we all know drafting someone with unwashed riding gear isn't pleasant? Do we really think those viruses go out of their way to take a different course?
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Old 12-18-20, 11:54 AM
  #29  
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Originally Posted by Biker395 View Post
There are a lot of factors at play. To be infected, you need to have a certain number (no one knows how many) of virons that you inhale or otherwise consume in a vulnerable area over a period of time. Given all those factors, you really can't make a lot of conclusions and extrapolate about what is safe and what is not. One means to know what is safe and what is not is contact tracing, and studies have shown that you can be infected at pretty good long distances, but indoors and if you are there for a significant period of time ... I think the latest I saw was as little as 10 minutes and 20 feet away. Outdoor transmission remains rare, let alone outdoor transmission at long distances and with a lot of turbulent flow.

There is no such thing as zero risk, and it is wise to avoid known significant risks. I begged off of a ride with a friend who was exposed to someone with COVID (he later tested negative). But if walking behind someone outdoors and 60 feet away were enough to be infected, I'm pretty sure we would have seen a lot more infections than we've seen. What I've read is pretty clear about what the problem is ... people gathering together indoors with family and friends and in particular during the holidays.
I'm very much aware that time and distance both play a role with regard to infection.
I posted that info as an attempt to explain why the theory of 60' thst you mention is still embraced by some cyclists. 60' is covered quickly on a bike.
That is why I posted a response.
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Old 12-18-20, 11:57 AM
  #30  
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Originally Posted by mstateglfr View Post
I'm very much aware that time and distance both play a role with regard to infection.
I posted that info as an attempt to explain why the theory of 60' thst you mention is still embraced by some cyclists. 60' is covered quickly on a bike.
That is why I posted a response.
Gotcha.
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Old 12-18-20, 02:08 PM
  #31  
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I ride solo so no worries but I would keep a distance from a cyclists ahead of me. Advantage of being in a rural area.
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Old 12-19-20, 05:03 AM
  #32  
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Originally Posted by genec View Post
Apparently you have never drafted cyclist that sneezed.
That's why I wouldn't draft.
That also has literally nothing to do with the article and graphic you posted.

Did you actually read past the first sentence of my post?
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Old 12-19-20, 05:16 AM
  #33  
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Originally Posted by 79pmooney View Post
May I point out that we all know drafting someone with unwashed riding gear isn't pleasant? Do we really think those viruses go out of their way to take a different course?

May I point out that's absurd reasoning? The one thing that the graphic showed that was relevant is that the particles immediately start dropping as soon as they're released. I and you have no idea how the "buoyancy" of odor-causing agents compare to virus containing exhalants. You're the second person to miss that I said I wouldn't draft because the safety is unproven, but that the stuff linked is largely irrelevant to telling us one way or the other.

And yes, your head going through the cloud of exhaled particles at bicycle speed is going to affect where they go. Last time I checked, my head doesn't pass through any cloud of BO I'm producing on a bike.

The problem with this thread is that people are trying to draw generalizations from modeling based on very specific assumptions. That really doesn't work.
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Old 12-19-20, 10:54 AM
  #34  
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Originally Posted by livedarklions View Post

The problem with this thread is that people are trying to draw generalizations from modeling based on very specific assumptions. That really doesn't work.
Hear, hear !
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