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Rednaxs60

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[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=214929#p214929:2ek1hvkr said:
skiri251 » Yesterday, 3:11 pm[/url]":2ek1hvkr]
[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=214927#p214927:2ek1hvkr said:
joedrum » Fri Dec 13, 2019 3:53 pm[/url]":2ek1hvkr]
Hmmmm in Florida ..where it get dangerous is close to the ocean crossing the intercostal waterway on bridges made high enough for big boats to pass through ..when you get blown around there’s no place to go really ..skyline parkway over Tampa bay really bad too ...I’ve had some bad moments in severe cross winds

That sounds totally scary. I don't like riding on high bridges without any cross wind to begin with.

There is one tall bridge from my house to Long Beach. That is also really high for cruise and cargo ships.
The surface is steel grid so steering feels funny.

When Sonya and I rode back from the Big Sur camping trip two years ago, we crossed the bridge at Astoria, the Astoria-Megler bridge, and it was brutal as well. Hate crosswinds.

Have found with grated bridges that speed is your friend, something like riding the wing on gravel, keep the speed. When you slow down is when you have issues.

Cheers
 
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skiri251

skiri251

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Well I guess the best is to avoid high bridges. LOL
I can do that to go to Long Beach.

But if I am out touring, there may not be a choice... especially cross winds.
 
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skiri251

skiri251

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Okay. Went out to usual nearby twisty for eaves wind test with my son on the back.

Parked next to Trump Golf Course. LOL
IMG_20191214_111607.jpg

IMG_20191214_111352.jpg

IMG_20191214_111452c.jpg

Eventually made it up to 60MPH. No vibration.

Tried radiator heater also. Air temp was around 60F and I felt warmth on my knees. That means it's not going to be super warm in colder situation.

My son says air hits lower part of the torso. There are deflectors on face height. So I should attach them below that too.

Overhead air vent didn't work as expected (no rush of air on my face.) I guess because the intake is in an air pocket created by the wind shield.
IMG_20191214_115133.jpg

Need to extend the intake.

Overall, very good result!
 

DaveKamp

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Calgary to Canmore... I experienced viscious sidewinds from Calgary to Brooks, but fortunately, I was in a rental car! I remember looking over my right shoulder, seeing down a long, but not very deep valley, and on the other side, I thought I saw the city lights of Lethbridge AND Great Falls...

Joe hit nail on head with bridges down there, but the spots that REALLY get 'ya, especially a bit north of him, are where you're riding down that long tunnel of trees, and THEN cross a bridge. Up here, it is rolling hills and trees, broken by bridges over smaller river valleys. Get north of me an hour, and you're in the 'driftless' region (no glaiciers flattened it) so you're blasting down a long hill, between forests, and then you cross a deep gulley with really strong wind coming up the chasm... and they're ALL pucker-factors. I'm certain that road that goes from Rutledge, TN up into Cumberland Gap is pretty spooky as you cross the top, but never been over it in anything lighter than 9800lbs.

Skiri- Keirin is a really intense sprint-racing format, and it is VERY highly ruled-and-regulated... so much that back when I was track-fodder, aside from the Olympics, the 'original' flavor really only happened in Japan. It's really not considered a 'sport' competition in the world of competetive cycling, because it's more of a gambling format, than a 'race'... but yes, aerodynamics is important, but not nearly as much as solo events. Keiren is kinda like taking a NASCAR race, with a pace-car start, getting up to speed, and only doing 3 laps after. Essentially, everyone lines up behind the pacer, everyone gets up to speed, and they're all in the pacer's draft. Once up to speed, they approach the last pace lap, and from that point, everyone sprints. Because of how it works, the aerodynamic advantage only helps you conserve energy as you speed up. Sprinting makes you aerodynamically VERY messy, and because of the 3 laps being somewhat short, you can't pass someone if you're in their draft. Really, it's about having brutal stamina, and the ability to spin without hitting the next guy, and being able to keep from getting tangled up in guys that do. Keirin has three types of riders: Winners, loosers, and the guys lying in a tangled pile of twisted metal and other cyclists in the infield. It's basically like off-track-betting on horse-racing, but the horses are very crazy guys on very regulated bicycles.

The V-strom... what a great machine... that was my 'other' choice when I was looking at, when my buddy offered me the GL1200... incredibly nimble handling, incredible clearance, great road manners, crazy-easy torque, no 'buzzy' vibes, and docile idle. I would venture that the reason the VSTROM would exhibit less sidewind-reaction is PROBABLY due to the fact that, aside from a little bit of front fender, there's no bodywork, and very little big of front wheel sticking out in front of the point where the front wheel contacts the road.

BTW... here's a bicycle in my south porch that y'all might like to see... it's a Brennan, ridden by Albert Byrd in the 1936 Berlin Olympics.
1936 Berlin Olympics Brenner for Albert Byrd.jpg

You'll see it's brother here:
https://classiccycleus.com/home/al-sellingers-brennan/
Note the shape of the head-tube lugwork... Brennan's trademark was the 'bikini-strap' lines around the front.

And no, the wheels aren't rusty. They're WOOD... and the sprockets look funky because skip-tooth is necessary for 'block' type chain designs of that vintage.

The 'faster is better' is DEFINITELY the way to manage 'grate' bridges. This comes from gyroscopic force of the spinning wheel... when you spin a wheel, the faster it's spinning, the MORE it dislikes having it's angle with respect to space changed.
 
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skiri251

skiri251

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Well, I don't know much about bicycles. I understand high-end models are very expensive.

When I was young and touring on my motorcycle, I saw lots of bicycle tourers on the road, camp grounds, and train stations (we used to sleep under the eaves of train stations in a city if we couldn't find a camp site.)
But typically motorcycle riders and bicycle riders didn't mingle. LOL
I got my limited knowledge from riders who like both motorcycles and bicycles.
But I can appreciate the beauty of the vintage racer you have.

Keirin was only known as publicly managed gambling in Japan before Koichi Nakano participated in World Championship track races in the West and won consecutive championships for many years but I thought that format was closer to Keirin.

There is another form of gambling called "Auto-race" which is like flat track motorcycle race in the US. (Despite its name, it is performed by motorcycles, not on the dirt but paved oval track.)
I don't know how competitive Japanese auto-racers will be in the US flat track. I don't think any one tried it. So it remains as just public gambling.
 

saganaga

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[url=https://classicgoldwings.com/forum/viewtopic.php?p=214951#p214951:ke9uthcm said:
DaveKamp » Today, 5:59 pm[/url]":ke9uthcm]
here's a bicycle in my south porch that y'all might like to see... it's a Brennan, ridden by Albert Byrd in the 1936 Berlin Olympics.

"A" bicycle? You always need n+1 bicycles!

Cool bike though.
 

DaveKamp

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Mebbie N ^2 :smilie_happy:

I think there's something like 16 bicycles in my basement right now... :whistling:

They sure take up less space than motorcycles... and all those license plates add up... :rant:

High end expensive... yeah, I suppose... but with the economy of scale of composites now, a guy can get a really good performer at a whole lot less. My Cannondale Synapse was retailed something around 3k... I got it as year-end for $2400... and the surprising thing about that old Brenner, is that it's basically the same weight as my CannonDawg...

...of course, the Brenner doesn't have a chain on it right now (block chains of the '30's, compared to rollers of the '50's, are over twice the weight), and it doesn't have brakes, or a 11-speed freewheel, or a second chainring, grip-shifters, water-bottle cages, or clipless pedals...
 

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skiri251

skiri251

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[url=https://classicgoldwings.com/forum/viewtopic.php?p=214974#p214974:3tf6l2a9 said:
DaveKamp » Sun Dec 15, 2019 9:47 am[/url]":3tf6l2a9]
Here's some really cool things to consider:

This one just needs a bubble cover:
https://media.treehugger.com/assets/images/2011/10/214-mpg-diy-honda-bike-photo01.jpg

This one is Da Bomb!!!
https://pictures.topspeed.com/IMG/crop/200902/untitled-4_600x0w.jpg

And this site is a serious rabbit-hole of insane experimentation coolness:
https://www.odd-bike.com/
particularly the RoHorn Racer...

:hihihi: :hihihi: :hihihi: :hihihi:

The bubble does 214 MPG! With like 125cc engine?
I wonder what the cross wind stablity will be though..
Also can he put his feed down to stop?

The bomb looks similar to land speed racers I see on El Mirage dry lake bed.

Yes, RoHorn racer is really cool. Another hub center steering example.
 

DaveKamp

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The bubble does 214 MPG! With like 125cc engine?
I wonder what the cross wind stablity will be though..
Also can he put his feed down to stop?

I'm certain that you'll find the cross-wind stability better with full enclosure, than with open sides. The open sides present lateral drag that being closed in is substantially less... but hey, it's a 125cc scooter... it doesn't weigh much more than a well-fed rider...

I was thinkin' about that with your beastie... I'm sure there's SOME thing there... on streamliner bicycles that I saw, there was a little lever that kicked down drag-stands like what's on Joe's Hooch... but they had roller-skate wheels. From what I saw, guys didn't use the drag-stands for anything but starting up, because they usually ended up passing out at the end of a run... once they got slow enough to stop, well, they just fell over anyway... :smilie_happy:

https://www.youtube.com/watch?v=UzXWMi9uSzo

https://www.youtube.com/watch?v=-CPc7ACDkqg
 
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skiri251

skiri251

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LOL

Those YouTube videos remind me of Wacky Races.

There is bicycle land speed record competition held every year on rural highway somewhere in Uta(?) desert. They look really cool.

Back to the 214MPG motorcycle, I guess it's just for competition so no need to worry about falling down at trafic light. LOL

I'm certain that you'll find the cross-wind stability better with full enclosure, than with open sides.

So you think I should close the sides of my RoofedWing?
Wait, I just watched TV news that high roof semi-trailer truck got overturned by cross wind. (Which I hear from time to time.)
I think it will be less likely if the semi is not hauling fully enclosed box.
 

joedrum

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Well on 2 wheels and fully enclosed So to speak ...there is nothing aero going on from cross winds ....certainly nothing stabilize about the set up ...a trike is something else and completely more stabilized..like your leaner ...sheesh a semi going past you at a high speed could cause trouble...heck they can on regular bike ....
 

DaveKamp

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I'm certain that you'll find the cross-wind stability better with full enclosure, than with open sides.

So you think I should close the sides of my RoofedWing?
Wait, I just watched TV news that high roof semi-trailer truck got overturned by cross wind. (Which I hear from time to time.)
I think it will be less likely if the semi is not hauling fully enclosed box.

The most likely semi overturning circumstance (due to wind, anyway) is a totally unladen box van... but that's because it has a sail, and no ballast. That's like a sailboat with no keel... actually, worse in a way... but they blow over because a crosswind exhibits substantially more force on one side of the vehicle, than the other... but comparing it to a flatbed isn't a relevant example, because the flatbed doesn't have the surface area for aforementioned surface pressure, so it isn't a comparable exercise in dynamics. A more comparable, would be to take the empty box van, and cut a pair of 8ft high, 25ft holes in the sides.

The coefficient of drag of an object determines how well fluid pressure (air) can 'grab' the object... and it can be easily seen in a wind-tunnel test, particularly a smoke-trail observation. A very aerodynamic object will pass a skinny little smoke trail over it, and after, will remain a very small smoke trail. A poorly shaped object will generate turbulence that rapidly disperses the smoke trail as a 'tell-tale' to where the designer needs to focus improvement. (btw... a clear polycarbonate intake manifold, when subjected to fuel-stream, will show very clearly that a little turbulence in the flow is good for mixing fuel for this very same reason)

Undisturbed airflow over a smooth surface is referred to as 'laminar'... meaning, it doesn't cause turbulence. In an airfoil, ideal airflow over a wing is 'laminar', because turbulent areas along the wing, and immediately behind the wing cause stall (and if the tail falls into that turbulence, tail lift is lost in what's referred to as 'high stall'). In any airfoil, the air pressure, as it travels over either the upper, or the lower side of the airfoil is being changed... specifically, when air flows over the 'top' side, the air must travel a longer distance than under the 'bottom'. The result, is that the airflow over the top must travel at a higher speed than the bottom, in order to arrive at the trailing edge at the same time, hence, differential pressure exists... aka 'lift'.

A hole in the side of an object presents a considerable disturbence to surface pressure. Imagine driving a car down the interstate at 80mph, and rolling down the windows on one side... you may not fully feel the pull to one side, but you've created a substantial disturbence, thus, a displacement of lift.

Let's say I'm moving in a straight line on my 1200. It's not the most aerodynamic thing on the planet... it's got lots of frontal area, lots of rough edges dragging through the air... and anyone riding behind me will feel the huge turbulent 'hole' I'm hammering through the atmosphere as I rumble along. It is, however, much more efficient moving through the air in the forward direction, than if I was going SIDEWAYS.

Going in a straight line through air, assumes that the angle of attack is directly in the line of travel, but when I'm blasting west in I-80 at 70mph, with a 20mph headwind out of the southwest, the apparent wind angle is hitting my left elbow, thigh, and shoulder at about 15 degrees from center, and I'm leaning to the left to compensate. If I had substantially LESS drag, I would less notice the side-force, than the side-force. It will still appear, because there's much more surface area on the side, but it will be less drag than having no 'shell'.

Try driving in a heavy crosswind with the windows up, then roll 'em down. :whistling:
 
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skiri251

skiri251

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Well I took fluid dynamics course in my university days so I know laminar flow, boundary layer, Raynolds numbers etc. (Although I totally forgot the details LOL.)
But to me it is a bit counter intuitive that a simple box has smaller coefficient of drag than a box with a large hole.
A box with a large hole has much smaller projected area than a simple box.
The projected area should be roughly proportional to the coefficient of drag.
Also I think it is a fact that naked motorcycles are less susceptable to cross wind than the ones with large fairings.

So to me it's projected area vs turbulance trade off.
Only if I had a wind tunnel in my garage (LOL), I can put all the theories to rest with actual experiment.
To experiment by actually riding in a cross wind, I need to invest money and time to make RoofedWing a box.
If I am 100% certain that a box is better, I will start a build but are you 100% sure?

I guess I should make a tiny wind tunnel and experiment with models.. That's better than real life test where I cannot control cross wind speed and only use my gut feeling to measure stability.
 

DaveKamp

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The thing that's counter-counterintuitive, is that the HOLE in the box adds more surface... because airflow comes IN, and bounces around, and tries to find some way out, and in the process, makes a big turbulent mess. Roll down one front window, and one rear window of your car, and when you get to the point where the buffeting makes you hurl chow, you've found it! :mrgreen:

Well lessee... election time is coming... there's gonna be a ton 'a those corrugated plastic signs (what's that stuff called... "Coroplast'? something like that... and duct tape... and since duct-tape hinges, and duct-tape closure was already proven by that other guy...

Okay, home-brew wind tunnel... yeah, I think that's entirely doable... you're gonna need a fairly healthy furnace blower... and you'll need some way of creating a smoke trail. If you wanted to be REALLY far-out, find a concrete culvert underneath a highway and set up there (set up a GoPro, so we can all see you try to explain it to the local police! :Egyptian: )

I think the biggest challenge, will be to get a sufficent and stable volume of air moving through the area around the bike, to yield repeatable demonstration of turbulent vs. laminar flow.

Y'know, you could retire from your day job, build a wind tunnel in your back yard, and rent time on it (like a chassis dyno)...

(mebbie Cheech and Chong would be interested in getting you a franchise deal for some industrial-strength smoke generation... and you could have snack vending machines at the far end?)

But seriously, guys built some amazing stuff with damned near nothing but good ideas, a long time ago, and what you have going here is certainly worthy of that genre... I'm certain some homebrew test-lab ingenuity would yield viable and repeatable results.

By the way, every February 27th, I put on a bright green tie in observance of Kelly Johnson Day...
 
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skiri251

skiri251

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The thing that's counter-counterintuitive, is that the HOLE in the box adds more surface... because airflow comes IN, and bounces around, and tries to find some way out, and in the process, makes a big turbulent mess. Roll down one front window, and one rear window of your car, and when you get to the point where the buffeting makes you hurl chow, you've found it! :mrgreen:

A car with two windows open is no way near to a box with a "large" hole.
It doesn't increase projected area either (by definition.)
The current RoofedWing has a "huge" (LOL) hole, also the rear is completely open and it's much narrower than a car so not much air is trapped.
Compare semi with a box with no hole and a flatbed with the same size box but just a frame with only the top closed.

You didn't say 100% sure so I guess you are not 100% sure. (LOL)

The bottom line, you just can't say that a simple box has smaller coefficiant of drag than a box with any hole.
It all depends on the details.

I don't really need a life size wind tunnel. A small one with a box fan and a scale model will do.
It's scalable.
That's what airplane designers do.
 
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skiri251

skiri251

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[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=215035#p215035:2xqt1njj said:
joedrum » Wed Dec 18, 2019 12:48 pm[/url]":2xqt1njj]
:smilie_happy: No wind tunnel build sheesh .....

Certainly no life size wind tunnel. LOL

But maybe I will make a small desktop version with 12VDC computer cooling fan. I have an adjustable voltage power supply so just put tiny models in front of the fan and gradually increase the voltage until they are overturned.
 

claydbal

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enjoyed yalls conversation. im a dumbass. had a 1965 ford econoline van. had a 1965 sportster. the van would cross a 4 lane highway with little wind. the sportster wasnt affected much .
 

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