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#11
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Bicycle helmets with wings.
On 7/24/2014 7:48 AM, Duane wrote:
On 7/24/2014 8:26 AM, AMuzi wrote: On 7/23/2014 7:46 PM, Jeff Liebermann wrote: How to make a light weight helmet. As long as you're moving, the wings provide lift, which makes the helmet feel lighter. (Ailerons, flaps, and spoilers optional): http://www.instructables.com/id/DIY-Hermes-Helmet/ http://cdn.instructables.com/FIW/0HNQ/HRTKK6CE/FIW0HNQHRTKK6CE.LARGE.jpg http://www.cincinnati.com/picture-gallery/entertainment/arts/2014/07/16/cincinnati-opera-singer-shows-off-wings/12759505/ http://www.toyanxiety.com/images/view.aspx?productId=10833 https://www.flickr.com/photos/kfergos/4844514671/in/photostream/ https://www.flickr.com/photos/kfergos/4844514601/in/photostream/ http://www.yellowjersey.org/photosfr...t/ringhead.jpg You should publish a book of photos. Maybe one about my special computer service technique: http://www.yellowjersey.org/photosfr...t/FIXCOMPU.JPG -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
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#12
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Bicycle helmets with wings.
On 7/24/2014 9:06 AM, AMuzi wrote:
On 7/24/2014 7:48 AM, Duane wrote: On 7/24/2014 8:26 AM, AMuzi wrote: On 7/23/2014 7:46 PM, Jeff Liebermann wrote: How to make a light weight helmet. As long as you're moving, the wings provide lift, which makes the helmet feel lighter. (Ailerons, flaps, and spoilers optional): http://www.instructables.com/id/DIY-Hermes-Helmet/ http://cdn.instructables.com/FIW/0HNQ/HRTKK6CE/FIW0HNQHRTKK6CE.LARGE.jpg http://www.cincinnati.com/picture-gallery/entertainment/arts/2014/07/16/cincinnati-opera-singer-shows-off-wings/12759505/ http://www.toyanxiety.com/images/view.aspx?productId=10833 https://www.flickr.com/photos/kfergos/4844514671/in/photostream/ https://www.flickr.com/photos/kfergos/4844514601/in/photostream/ http://www.yellowjersey.org/photosfr...t/ringhead.jpg You should publish a book of photos. Maybe one about my special computer service technique: http://www.yellowjersey.org/photosfr...t/FIXCOMPU.JPG Good thing I don't haven any lighter fluid at the office right now. My favorite is the guy in the dress. lol |
#13
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Bicycle helmets with wings.
On Thu, 24 Jul 2014 18:35:45 +0700, John B. Slocomb
wrote: They probably will work. But... I read of cyclists doing 100 KMH down some of the hills in France. Try sticking your arm out of the car window at 60 MPH and imagine if you had a wing attached. I was probably 12 years old at the time. All I remember was the giant dent I put in the neighbors car door. The impact must have been substantial as my wheels had steel rims, which are quite difficult to potato chip. A good idea but you would need some sort of automatic closing device. Perhaps similar to the air bags in a car where a blank shotgun shell fires and the gas inflates the bag. To match the present helmets the switch could be set for a force equal to a 14 MPH shock - about the same as falling slightly under 1 meter and BAM your lid closes :-) Ummm... not thanks. I think simply a few tension springs to make the lid normally closed will suffice. The lift from the wings will open the lid when moving, and close it when stopped. Presumably, when there's an accident in progress, the airflow would be interrupted by a sudden change in position, thus allowing the springs to close the gap. A pressure locking system would also help. But to carry that idea a bit further, why not an inflatable suit with the gas generator. A slight shock and BAM you inflate and go bouncing down the hill like a beach ball. see http://tinyurl.com/odlfdd7 for several preliminary design concepts. Wearable air bags have their appeal, but tend to be expensive. For example, the replacement air bag on a friend's vehicle cost $600 to replace and that was a bargain. If bicycle air bags were similarly priced, you could easily spend the purchase price of a new bicycle every time the air bag deploys. No thanks. Also, wearable air bags would probably fail the fashion and aesthetics test. I should probably patent that idea. "Motion activated bifurcated bicycle helmet mechanism for improved cranial cooling". -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#14
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Bicycle helmets with wings.
On Thursday, July 24, 2014 1:26:59 PM UTC+1, AMuzi wrote:
On 7/23/2014 7:46 PM, Jeff Liebermann wrote: How to make a light weight helmet. As long as you're moving, the wings provide lift, which makes the helmet feel lighter. (Ailerons, flaps, and spoilers optional): http://www.instructables.com/id/DIY-Hermes-Helmet/ http://cdn.instructables.com/FIW/0HNQ/HRTKK6CE/FIW0HNQHRTKK6CE.LARGE.jpg http://www.cincinnati.com/picture-gallery/entertainment/arts/2014/07/16/cincinnati-opera-singer-shows-off-wings/12759505/ http://www.toyanxiety.com/images/view.aspx?productId=10833 https://www.flickr.com/photos/kfergos/4844514671/in/photostream/ https://www.flickr.com/photos/kfergos/4844514601/in/photostream/ http://www.yellowjersey.org/photosfr...t/ringhead.jpg You gotta carry your touring spares somewhere. Andre Jute |
#15
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Bicycle helmets with wings.
On 24/07/14 21:35, John B. Slocomb wrote:
On Wed, 23 Jul 2014 23:54:07 -0700, Jeff Liebermann wrote: On Thu, 24 Jul 2014 11:37:12 +0700, John B. Slocomb wrote: There is a fundamental flaw in the Hermes Helmet. Above a certain velocity the helmet will provide sufficient lift to counteract the weight of the bicycle and rider and at that time all traction will be lost possibly resulting in severe accidents as the airborne "rider" is unable to corner. You mean all these won't work? https://www.google.com/search?q=bicycle+with+wings&tbm=isch It seems such a common design idea that at least one of these might fly. I vaguely recall adding wings when I was very young. I flew about 10ft before turning the front wheel into a potato chip by smashing into a parked car. They probably will work. But... I read of cyclists doing 100 KMH down some of the hills in France. Try sticking your arm out of the car window at 60 MPH and imagine if you had a wing attached. You're wrong. Lift is controlled by the angle of attack. Put your head up and make the helmet lighter by increasing the angle of attack above zero degrees (horizontal). Drop your head so the angle of attack is less than zero degrees, and the wing actually pushes down on your head. The force is transferred to your tyres, and you can corner faster and brake harder - just like the wings on an F1 car! -- JS |
#16
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Bicycle helmets with wings.
On 7/24/2014 6:15 PM, James wrote:
On 24/07/14 21:35, John B. Slocomb wrote: You're wrong. Lift is controlled by the angle of attack. Put your head up and make the helmet lighter by increasing the angle of attack above zero degrees (horizontal). Drop your head so the angle of attack is less than zero degrees, and the wing actually pushes down on your head. The force is transferred to your tyres, and you can corner faster and brake harder - just like the wings on an F1 car! I know - servo-controlled wings, whose pitch angle is controlled via feedback from a force sensor! Make it rider-tunable so the apparent weight of the helmet fits the rider's individual preference. Shimano can work on this after they've got us all using electronic shifting. It will give their EEs something to do. -- - Frank Krygowski |
#17
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Bicycle helmets with wings.
On 25/07/14 10:01, Frank Krygowski wrote:
On 7/24/2014 6:15 PM, James wrote: On 24/07/14 21:35, John B. Slocomb wrote: You're wrong. Lift is controlled by the angle of attack. Put your head up and make the helmet lighter by increasing the angle of attack above zero degrees (horizontal). Drop your head so the angle of attack is less than zero degrees, and the wing actually pushes down on your head. The force is transferred to your tyres, and you can corner faster and brake harder - just like the wings on an F1 car! I know - servo-controlled wings, whose pitch angle is controlled via feedback from a force sensor! Make it rider-tunable so the apparent weight of the helmet fits the rider's individual preference. Shimano can work on this after they've got us all using electronic shifting. It will give their EEs something to do. Perhaps it's been done... http://tinselblog.files.wordpress.co...bddvddc-2d.jpg -- JS |
#18
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Bicycle helmets with wings.
On Fri, 25 Jul 2014 08:15:04 +1000, James
wrote: On 24/07/14 21:35, John B. Slocomb wrote: On Wed, 23 Jul 2014 23:54:07 -0700, Jeff Liebermann wrote: On Thu, 24 Jul 2014 11:37:12 +0700, John B. Slocomb wrote: There is a fundamental flaw in the Hermes Helmet. Above a certain velocity the helmet will provide sufficient lift to counteract the weight of the bicycle and rider and at that time all traction will be lost possibly resulting in severe accidents as the airborne "rider" is unable to corner. You mean all these won't work? https://www.google.com/search?q=bicycle+with+wings&tbm=isch It seems such a common design idea that at least one of these might fly. I vaguely recall adding wings when I was very young. I flew about 10ft before turning the front wheel into a potato chip by smashing into a parked car. They probably will work. But... I read of cyclists doing 100 KMH down some of the hills in France. Try sticking your arm out of the car window at 60 MPH and imagine if you had a wing attached. You're wrong. Lift is controlled by the angle of attack. Put your head up and make the helmet lighter by increasing the angle of attack above zero degrees (horizontal). Drop your head so the angle of attack is less than zero degrees, and the wing actually pushes down on your head. The force is transferred to your tyres, and you can corner faster and brake harder - just like the wings on an F1 car! To get technical about it, lift depends on the shape of the airfoil AND the angle of attack. A well designed airfoil can generate lift at zero angle of attack. In fact the common Clark "Y" airfoil has a positive coefficient of lift at zero angle of attack and requires about a negative 6 degree angle of attack to provide zero lift. -- Cheers, John B. |
#19
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Bicycle helmets with wings.
On Fri, 25 Jul 2014 08:15:04 +1000, James
wrote: You're wrong. Lift is controlled by the angle of attack. Put your head up and make the helmet lighter by increasing the angle of attack above zero degrees (horizontal). Drop your head so the angle of attack is less than zero degrees, and the wing actually pushes down on your head. The force is transferred to your tyres, and you can corner faster and brake harder - just like the wings on an F1 car! Nascar is way ahead of us in the performance hat area. http://media.photobucket.com/user/spoilercaps/media/spoiler-logo2.jpg.html The spoiler probably is more useful at providing downward pressure to keep the hat from flying away at speed, but could be inverted to provide some lift. However, at comfort bicycle speeds, I suspect a powered wing hat might be more effective. There just isn't enough air speed available at the speeds I like to ride. Looks like someone has anticipated the need and done some work on the basic design: http://www.dailyhaha.com/_pics/bird_head.jpg -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#20
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Bicycle helmets with wings.
AJ
http://en.wikipedia.org/wiki/Frontier_Thesis https://www.google.com/search?tbm=bk...ated+with+the+... the woman riders photo blog is an essay on myth to practice... Lieb lives in a town OF practice to myth... ceptin at the front edge. |
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