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Old 11-20-2013, 08:30 PM   #46
fallingoff
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Quote:
Originally Posted by joexr View Post
Personal attack or personal compliment?
In my opinion I think its a number of reasons
Some bikes are better in a cross wind.
Speed more gyroscopic effect.
Low cog.
Riding technique
Sail area of bike.
As mention early
The best bike I have ridden
In very strong crosswinds
Was my k12s with
The boss on the back.
Plenty of different
Types of bikes on the run one day.
I was having problems
On the k but when I watched
The hd,jap sports,tourers
Adv type bikes
Laverdas,ducatis
Getting smashed
I was glad I was on the k.
Oh weight,etc
All effects.
Plus road surface, wet etc.
2 c
Cheers
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Old 11-20-2013, 08:34 PM   #47
JimVonBaden
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Quote:
Originally Posted by Ray0of0Sun View Post
Ah, alas, the erroneous personal attack.
Not erroneous, earned.

Sometimes you just have to step back and accept that the other person is a troll or an idiot. No amount of logic or corroboration will change the course of the debate!

Jim
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Old 11-21-2013, 12:25 AM   #48
996DL
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Aerodynamics, surface areas, weight and load placement and the many other contributing factors already mentioned, all play a role including a rider's own techniques, but who really gives a God Damn in regards to their order of significance.

But the routine chest beating of the forum's self proclaimed experts, is as tedious as ever.

Thrilled to finally be rid, of my former flying kite / billboard DL1000.

996DL
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Old 11-21-2013, 01:11 AM   #49
fallingoff
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Quote:
Originally Posted by 996DL View Post
Aerodynamics, surface areas, weight and load placement and the many other contributing factors already mentioned, all play a role including a rider's own techniques, but who really gives a God Damn in regards to their order of significance.

But the routine chest beating of the forum's self proclaimed experts, is as tedious as ever.

Thrilled to finally be rid, of my former flying kite / billboard DL1000.

996DL
Well that added a lot.
Lol
Cheers
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Old 11-23-2013, 06:10 AM   #50
helotaxi
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The ratio of frontal area presented to the relative wind to mass and the aerodynamic form factor presented to the relative wind are factors that are really going to matter. The rider has an effect, but the question is about the bike.

That makes for 3 real factors with the rider assumed a constant. To picture the first, imagine two identical bikes except one has a magnesium frame (really light) and the other has a tungsten frame (really heavy). The heavier bike in that case will have less issue with the wind. Likewise a light bike with low relative frontal area may do better than a porker with a lot of relative frontal area.

Form factor is the aerodynamics of the bike itself. Think wind tunnel. Smooth laminar flow where the smoke lines in the tunnel stay in nice concise lines until well behind the bike will slide through the wind better than turbulent flow that breaks the smoke trails all to hell immediately.

Finally there is the "relative" part of the wind. When the bike is moving, you have 2 wind components: the bike's movement relative to the planet on a calm day creates wind relative to the bike. The air moving relative to the planet creates wind relative to the bike as well. The vector sum of these two movements relative to the bike give you your relative wind. For a fixed crosswind, the angle of the resultant vector relative to the bike's direction of travel will change based on the bike's speed. The faster you're going, the less of the resultant drag vector (what actually moves the bike around in the wind) is working to push you off course. Additionally, in the case of a bike that is very aerodynamic from the very front (like a Hyabusa), going faster will move the relative wind more to the frontal aspect of the bike and reduce the lateral portion of the drag vector even further.
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Old 11-23-2013, 07:45 AM   #51
joexr
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Laugh

He said being aerodynamic and riding fast both help.
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Old 11-23-2013, 08:58 AM   #52
Nadgett
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Sportsters are much more stable in the wind than my buddy's Moto Guzzi Nevada, which is about 100 lbs lighter.

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Old 11-23-2013, 09:10 AM   #53
joexr
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Quote:
Originally Posted by Ray0of0Sun View Post
It's because they're more aerodynamic. :loll
They ARE.
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Old 11-23-2013, 09:16 AM   #54
Nadgett
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The Guzzi, on the other hand, is a whole lot easier to push around in the garage.
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Old 11-23-2013, 09:19 AM   #55
joexr
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Laugh

Quote:
Originally Posted by Nadgett View Post
The Guzzi, on the other hand, is a whole lot easier to push around in the garage.
But you'd have to push it less than the other too.
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Old 11-23-2013, 12:25 PM   #56
Nadgett
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The XR1200 is 12 lb lighter than your FJR, so you wouldn't have any trouble pushing it.
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Old 11-23-2013, 12:33 PM   #57
Pantah
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I think you just said that the faster you go, the less effect the crosswind with have on you. If that is what you said, I have first hand experience that your thesis is totally false. My KTM 950 was a tough bike to ride in the kinds of high winds you find around storms on the plains or the mid west. During the worst of them I had to keep my speed under 55mph just to stay on the road. Attempting to maintain 75 or so just didn't work. Then there is the issue of semi tractor trailers either passing me or me passing them. Always hairy.

Secondly, there isn't a motorcycle made that is aerodynamic to a side blast. That includes the Busa you mentioned.


And like I said earlier, my 300 pound Yamaha dual sport is the easiest I've had for riding in high wind conditions. The 500 pound 950 was the worst of them. You can tell why by just looking at one.


Quote:
Originally Posted by helotaxi View Post
The ratio of frontal area presented to the relative wind to mass and the aerodynamic form factor presented to the relative wind are factors that are really going to matter. The rider has an effect, but the question is about the bike.

That makes for 3 real factors with the rider assumed a constant. To picture the first, imagine two identical bikes except one has a magnesium frame (really light) and the other has a tungsten frame (really heavy). The heavier bike in that case will have less issue with the wind. Likewise a light bike with low relative frontal area may do better than a porker with a lot of relative frontal area.

Form factor is the aerodynamics of the bike itself. Think wind tunnel. Smooth laminar flow where the smoke lines in the tunnel stay in nice concise lines until well behind the bike will slide through the wind better than turbulent flow that breaks the smoke trails all to hell immediately.

Finally there is the "relative" part of the wind. When the bike is moving, you have 2 wind components: the bike's movement relative to the planet on a calm day creates wind relative to the bike. The air moving relative to the planet creates wind relative to the bike as well. The vector sum of these two movements relative to the bike give you your relative wind. For a fixed crosswind, the angle of the resultant vector relative to the bike's direction of travel will change based on the bike's speed. The faster you're going, the less of the resultant drag vector (what actually moves the bike around in the wind) is working to push you off course. Additionally, in the case of a bike that is very aerodynamic from the very front (like a Hyabusa), going faster will move the relative wind more to the frontal aspect of the bike and reduce the lateral portion of the drag vector even further.
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Old 11-23-2013, 05:06 PM   #58
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It's calm and 75* here in Florida.
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Old 11-23-2013, 09:41 PM   #59
helotaxi
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Quote:
Originally Posted by Pantah View Post
I think you just said that the faster you go, the less effect the crosswind with have on you. If that is what you said, I have first hand experience that your thesis is totally false. My KTM 950 was a tough bike to ride in the kinds of high winds you find around storms on the plains or the mid west. During the worst of them I had to keep my speed under 55mph just to stay on the road. Attempting to maintain 75 or so just didn't work. Then there is the issue of semi tractor trailers either passing me or me passing them. Always hairy.

Secondly, there isn't a motorcycle made that is aerodynamic to a side blast. That includes the Busa you mentioned.


And like I said earlier, my 300 pound Yamaha dual sport is the easiest I've had for riding in high wind conditions. The 500 pound 950 was the worst of them. You can tell why by just looking at one.
The problem you had with the KTM and the gusty winds relative to speed is a rider reaction time problem not your bike defying physics. The big KTM is not good in the wind and as you said, one look will tell you why. It like their styling cues came from the sails on a yacht.

And if you read my post, I never said that any bike was aerodynamic from the side. I said that going faster makes that less of a factor since speed reduces the crosswind relative to the total relative wind making the frontal drag more important.
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Old 11-24-2013, 06:59 AM   #60
helotaxi
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And there's a practical limit to how much you can reduce wind effects by going faster since the speed required is proportional to the wind velocity.
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