Most aero position for out front Garmin mount?

Discuss light weight issues concerning road bikes & parts.
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jekyll man
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by jekyll man

You could try it like Alf's brakes.....

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by Weenie


aerozy
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by aerozy

Riding a bike is fun partly because of the speed increaments you gain with training and buying the latest ultimate equipment. At the end of the day it all sums up. Is there a purpose to all of it? Meaning does it matter if we take 1min or 1min1s on our local run up the hill? No, but its part of the fun!

So back to the mount. I would guess having it dead flat, so aligned with the bars in order to achieve minimal frontal area.
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legs 11
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by legs 11

Shit, sorry mate.
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neeb
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by neeb

legs 11 wrote:Shit, sorry mate.
You mean about the Garmin? Yeah, second time it's died on me and this time it's out of warranty... First time it happened they sent me a replacement. It's the sweat from indoor training in the winter that does it (maybe exacerbated by having it horizontal for aero reasons which doubtless doesn't help run-off and definitely doesn't have any benefits when stationary... :wink: )

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DMF
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by DMF

As for least frontal area automatically being most aero, that's as far as cycling is concerned a bit of a myth.

What REALLY matters is HOW the air flows around an object, with regards to turbulence, low pressure zones, etc. "The aero tuck" just happens to be better for all of those things too with minimizing the low pressure zone on a riders back and streamlining the body, especially with TT bars, for less turbulence. Ofcourse "size matters" still.

But forget this BS about smallest frontal area being the end all solution to aero... Much of the drag does not come from the air you are pushing infront of you, it comes from the air behind you trying to suck you backwards.

LionelB
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by LionelB

Seriously the aero position of the garmin.... :roll:

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prendrefeu
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by prendrefeu

Really, the concern about what goes *into* the wind is a significant concern as speed increases. It becomes more important than what happens to the fluid (air or liquid) after passing over the object as an object approaches supersonic or hypersonic speeds. Let me write that one more time to emphasize it: supersonic or hypersonic speeds.

Up until then, it's important to have something heading into the fluid with minimal frontal area, but on balance it will be more effective to ensure that the flow of the fluid around the object is as smooth as possible. Therefore the majority of 'aero' considerations are not necessarily for what's headed into the fluid, but more concentrated on how the fluid moves around the object and in what state it leaves the surface of the object (disturbed or calm). Of course, making sure that the fluid flows smoothly around the object means that the front shape heading into the fluid also needs to enhance the flow of the fluid, which usually results in a 'rounded' frontal face or edge to some degree, but it does not necessarily need to be small.

http://en.wikipedia.org/wiki/Aerodynami ... l_concepts

So when you start nearing supersonic speeds on your bicycle you should be seeing aero shapes more concerned with the frontal area heading into the fluid.

In the meantime, just go ride your bike.


INB4 someone says "Air is not a fluid". Air is a fluid. Period. Water is also a fluid. The difference is that one is a fluid substance in a liquid state, the other is in a gaseous state. A fluid is a substance that has no fixed shape and yields easily to external pressure.

Also, if you need a quick mental example of the difference in shape concern of a subsonic object vs a super or hypersonic object:
Subsonic = Jet Airplane. Airbus A380, for example. Not very pointy, but very aero for shape as the fluid moves around the object.
Supersonic = think of a rocket. They have a sharp front tip, but usually the end is rather abrupt and not designed to care too much about turbulent flow. The primary concern is for breaking the density of the fluid (air) as it is compressed by the object's forward movement.
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Krackor
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by Krackor

DMF wrote:Exchange the question for "Most favourable place to save 10 grams on the bike?" and the answers would be a lot more constructive, even though it makes even less of a difference than 10 degree angle change of the Garmin might...


Differences in weight are easy to quantify on the scale, so even if it's impossible to tell the difference of 10 grams on the road, it's pretty easy to determine that shedding 10 grams will help you on a climb.

It's not so easy to quantify differences in aerodynamics because the forces involved are more complex and more dynamic than gravity. Even if you get a good measurement of aerodynamics in a controlled test environment, conditions may change in situ such that what you thought was more aero is actually less aero.

There's a good reason why advice about weight is more definitive than advice about aero, and it's not just because of the title of this forum.

kulivontot
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by kulivontot

With a TT helmet on, looking at your garmin can have a significant drag increase because that giant tail is sticking straight up into the wind. I have no wind tunnel data to support this of course....

solarider
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by solarider

Most aero angle of a Garmin? Has it really come to this? Have you seen the frontal area of one of those things?

Surely we need an F1 or aerospace engineer with knowledge of the aerodynamic properties of wings to contribute to this discussion? The angle must surely increase or decrease downforce on the front of the bike more than aerodynamic drag. Maybe you have inadvertently unlocked a new frontier of bike design - that of downforce! Maybe Garmin should design their next head unit with this in mind?

neeb
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by neeb

solarider wrote:Most aero angle of a Garmin? Has it really come to this? Have you seen the frontal area of one of those things?

Yup, about 5 square cm at 0 degrees and 50 at 90 degrees.
solarider wrote:Surely we need an F1 or aerospace engineer with knowledge of the aerodynamic properties of wings to contribute to this discussion? The angle must surely increase or decrease downforce on the front of the bike more than aerodynamic drag. Maybe you have inadvertently unlocked a new frontier of bike design - that of downforce! Maybe Garmin should design their next head unit with this in mind?

Have you thought about the negative aerodynamic potential of lugging such a humongous wit around with you?

RookieB
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by RookieB

End of the top tube behind & under the stem.
Not the best for reading but I dont look at my Garmin in a fast ride or bunch. Its just a recording device.
All the money ive spent on my Aero bike, im not sticking TV Screens on my bars.


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chanthony
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by chanthony

Most aero should be aligned with the stem but honestly, it should matter...IMHO, go with what makes the Garmin easiest to read. Happy riding!


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drainyoo
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by drainyoo

Most aero position? An app on your iPhone in your pocket.

But seriously, what does a Garmin Edge device provide over a smartphone with an app like Garmin or Strava? I don't have an experience with an Edge, but by skimming the features it seems like there are apps that provide the same benefits and features.

by Weenie


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rmerka
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by rmerka

Accuracy (except elevation) and battery life.

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