#11
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Handlebar bags
On Friday, October 23, 2020 at 5:16:27 AM UTC-7, Sepp Ruf wrote:
Andre Jute wrote: On Thursday, October 22, 2020, Frank Krygowski wrote: Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ -- - Frank Krygowski It's wishful thinking. Actually, there is one position where the bag might have some aero-effect, and it is the position Franki-boy's champion ignoramus assures us it would have no effect -- and where Ridealot tells us experience is it works. That's behind the saddle, where the bluff sides of the bag would form a sort of Kamm tail to shortcut the turbulence of the passage of the cyclist and his bike, which translates directly into reduced drag. See the work of Professor Kamm between the big wars, and the graphic of both my Lancia Fulvia (the Zagato Kammback and the standard factory 3-box coupe) at speed with the skeins of wool streaming behind it in my Building Special Cars (Batsford, London and Robert Bentley, Boston are the most accessible editions). Andre Jute Sleek & sophisticated Would you like to comment on this classic? https://drivetribe.com/p/in-1998-luigi-colani-presented-CVoUYr2pRvymeEWJfOj2fg Or this one? https://it.wikipedia.org/wiki/File:Schauff-Fahrrad,_Prototyp_Colani_(2019-10-07_Sp).jpg Yes, both are ugly. |
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#12
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Handlebar bags
On 10/22/2020 3:52 PM, John B. wrote:
On Thu, 22 Oct 2020 11:27:59 -0400, Frank Krygowski wrote: Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ Strange aerodynamics as the writer states that the bag makes him "consistently 2-4 mph faster on the steep downhills", but apparently not at other times?? Pack it full of rocks, I can almost guarantee you'll go downhill faster. .... and not go faster at other times. Mark J. |
#13
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Handlebar bags
On Fri, 23 Oct 2020 10:02:50 -0700, "Mark J."
wrote: On 10/22/2020 3:52 PM, John B. wrote: On Thu, 22 Oct 2020 11:27:59 -0400, Frank Krygowski wrote: Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ Strange aerodynamics as the writer states that the bag makes him "consistently 2-4 mph faster on the steep downhills", but apparently not at other times?? Pack it full of rocks, I can almost guarantee you'll go downhill faster. ... and not go faster at other times. Mark J. Yes, I hadn't thought of that. But Hey! An excuse for yet another bicycle - a "Downhill Bike" - perhaps with a lead frame? -- Cheers, John B. |
#14
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Handlebar bags
On Friday, October 23, 2020 at 1:16:27 PM UTC+1, Sepp Ruf wrote:
Andre Jute wrote: On Thursday, October 22, 2020, Frank Krygowski wrote: Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ -- - Frank Krygowski It's wishful thinking. Actually, there is one position where the bag might have some aero-effect, and it is the position Franki-boy's champion ignoramus assures us it would have no effect -- and where Ridealot tells us experience is it works. That's behind the saddle, where the bluff sides of the bag would form a sort of Kamm tail to shortcut the turbulence of the passage of the cyclist and his bike, which translates directly into reduced drag. See the work of Professor Kamm between the big wars, and the graphic of both my Lancia Fulvia (the Zagato Kammback and the standard factory 3-box coupe) at speed with the skeins of wool streaming behind it in my Building Special Cars (Batsford, London and Robert Bentley, Boston are the most accessible editions). Andre Jute Sleek & sophisticated Would you like to comment on this classic? https://drivetribe.com/p/in-1998-luigi-colani-presented-CVoUYr2pRvymeEWJfOj2fg At this link my attempt to look at the photograph was stymied by a demand to let them invade my computer at will and forever. **** that for a lark. Or this one? https://it.wikipedia.org/wiki/File:Schauff-Fahrrad,_Prototyp_Colani_(2019-10-07_Sp).jpg Maybe that sort of shell would be worth something on a racer. I really couldn't tell without time in a wind tunnel. I suspect that bike might have been difficult to control on a fast downhill, what with those hollow wings covering the handlebars creating a shifting pressure differential dancing around the top of the steering column, with a likely steering input, perhaps even consequent lift, with the result of a light front wheel, perhaps air between tyre and road, not great for roadholding and handling. A further stability problem on that bike will be created by the forward centre of aerodynamic pressure, which even academics didn't know so much about just after the war. I would have made the fairing longer over the back of the rear wheel or put up a fin or something to give more side area near the back to, as it were, draw the CoAP backwards for greater resistance to crosswinds or even mild crosscurrents set up by passing another rider, or being passed by him.. On the whole, I might have been impressed with the state of knowledge available in 1949, but today -- not so much. I liked Colani's V16 ultra-long Jaguar XK 150 lookalike hotrod better, but there is no escaping the fact that Colani was a flashy industrial designer, not an aerodynamicist. That bike shell you directed me to is a result not of a fascination with real aerodynamics but rather of his love affair with the fluid shape-properties of the then new glass-reinforced plastic (GRP), what Americans call fiber reinforced plastic or FRP. Generally speaking, I'm not overcome with admiration for efforts to improve bike aerodynamics. Most bikes are in fact as aerodynamic as they can be, and their total resistance to the air is only a small fraction of the dynamic resistance of a speeding bike, which always has a rider on top. It seems to me that people who worry about bike Cd have forgotten the part played by front area (as in CdA), and of course the frontal area of the rider is several times that of his bike. The most effective way to make a bike go faster at speeds where aerodynamics come into play in the results -- is for the rider to lose weight and become narrower. Andre Jute Svelte, fast, hungry |
#15
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Handlebar bags
On 10/23/2020 7:04 PM, John B. wrote:
On Fri, 23 Oct 2020 10:02:50 -0700, "Mark J." wrote: On 10/22/2020 3:52 PM, John B. wrote: On Thu, 22 Oct 2020 11:27:59 -0400, Frank Krygowski wrote: Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ Strange aerodynamics as the writer states that the bag makes him "consistently 2-4 mph faster on the steep downhills", but apparently not at other times?? Pack it full of rocks, I can almost guarantee you'll go downhill faster. ... and not go faster at other times. Mark J. Yes, I hadn't thought of that. But Hey! An excuse for yet another bicycle - a "Downhill Bike" - perhaps with a lead frame? We once had a club member nicknamed "Downhill Dick." He was quite portly and joked about his "aerobelly." And he was indeed fast on downhills. But aerodynamic features can make a difference, and it is most noticeable when coasting. I've mentioned before my tour with a friend of identical weight on practically identical bikes, carrying identical loads in our panniers. The only significant differences were that he was about 6" shorter than me (which should have been a coasting advantage) and I was using Specialized Tailwind panniers vs. his square profile Cannondale bags. I easily and markedly outcoasted him on every hill. -- - Frank Krygowski |
#16
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Handlebar bags
On Fri, 23 Oct 2020 20:42:19 -0400, Frank Krygowski
wrote: On 10/23/2020 7:04 PM, John B. wrote: On Fri, 23 Oct 2020 10:02:50 -0700, "Mark J." wrote: On 10/22/2020 3:52 PM, John B. wrote: On Thu, 22 Oct 2020 11:27:59 -0400, Frank Krygowski wrote: Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ Strange aerodynamics as the writer states that the bag makes him "consistently 2-4 mph faster on the steep downhills", but apparently not at other times?? Pack it full of rocks, I can almost guarantee you'll go downhill faster. ... and not go faster at other times. Mark J. Yes, I hadn't thought of that. But Hey! An excuse for yet another bicycle - a "Downhill Bike" - perhaps with a lead frame? We once had a club member nicknamed "Downhill Dick." He was quite portly and joked about his "aerobelly." And he was indeed fast on downhills. But aerodynamic features can make a difference, and it is most noticeable when coasting. I've mentioned before my tour with a friend of identical weight on practically identical bikes, carrying identical loads in our panniers. The only significant differences were that he was about 6" shorter than me (which should have been a coasting advantage) and I was using Specialized Tailwind panniers vs. his square profile Cannondale bags. I easily and markedly outcoasted him on every hill. Magic bags? Buy Our Bags and coast faster? -- Cheers, John B. |
#17
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Handlebar bags
Op zaterdag 24 oktober 2020 om 02:42:24 UTC+2 schreef Frank Krygowski:
On 10/23/2020 7:04 PM, John B. wrote: On Fri, 23 Oct 2020 10:02:50 -0700, "Mark J." wrote: On 10/22/2020 3:52 PM, John B. wrote: On Thu, 22 Oct 2020 11:27:59 -0400, Frank Krygowski wrote: Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ Strange aerodynamics as the writer states that the bag makes him "consistently 2-4 mph faster on the steep downhills", but apparently not at other times?? Pack it full of rocks, I can almost guarantee you'll go downhill faster. ... and not go faster at other times. Mark J. Yes, I hadn't thought of that. But Hey! An excuse for yet another bicycle - a "Downhill Bike" - perhaps with a lead frame? We once had a club member nicknamed "Downhill Dick." He was quite portly and joked about his "aerobelly." And he was indeed fast on downhills. But aerodynamic features can make a difference, and it is most noticeable when coasting. I've mentioned before my tour with a friend of identical weight on practically identical bikes, carrying identical loads in our panniers. The only significant differences were that he was about 6" shorter than me (which should have been a coasting advantage) and I was using Specialized Tailwind panniers vs. his square profile Cannondale bags. I easily and markedly outcoasted him on every hill. -- - Frank Krygowski Try a downhill with and without a flapping jacket. Never understood people on a roadbike with jerseys/jackets two sizes too big. You can overdo with the tight fit if you look at the struggle with their jackets of the Sunweb pro racers in the Stelvio Giro d'Italia stage two days ago. Lou |
#18
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Handlebar bags
On 10/22/2020 11:27 AM, Frank Krygowski wrote:
Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ Here's an interesting smaller handlebar bag by Route Werks, still just a Kickstarter project though: https://routewerks.us/ https://www.kickstarter.com/projects...by-route-werks |
#19
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Handlebar bags
On Saturday, October 24, 2020 at 12:37:05 PM UTC-4, Bertrand wrote:
On 10/22/2020 11:27 AM, Frank Krygowski wrote: Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ Here's an interesting smaller handlebar bag by Route Werks, still just a Kickstarter project though: https://routewerks.us/ https://www.kickstarter.com/projects...by-route-werks There are other sources for small handlebar bags, for example https://velo-orange.com/collections/...-handlebar-bag When I've made mine, I went the other direction. I made them as large as I thought reasonable. Weight increases roughly as the square of the size, carrying capacity increases roughly as the cube of the size. And I do think there are aero benefits to a larger bag. (Think of it as a smaller Zzipper fairing.) - Frank Krygowski |
#20
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Handlebar bags
On Saturday, 24 October 2020 12:50:48 UTC-4, Frank Krygowski wrote:
On Saturday, October 24, 2020 at 12:37:05 PM UTC-4, Bertrand wrote: On 10/22/2020 11:27 AM, Frank Krygowski wrote: Handlebar bags: Some of us like them. For some reasons, see "My PBP Bike: Rack and Bag" at https://www.renehersecycles.com/journal/ Here's an interesting smaller handlebar bag by Route Werks, still just a Kickstarter project though: https://routewerks.us/ https://www.kickstarter.com/projects...by-route-werks There are other sources for small handlebar bags, for example https://velo-orange.com/collections/...-handlebar-bag When I've made mine, I went the other direction. I made them as large as I thought reasonable. Weight increases roughly as the square of the size, carrying capacity increases roughly as the cube of the size. And I do think there are aero benefits to a larger bag. (Think of it as a smaller Zzipper fairing.) - Frank Krygowski Especially if you make the bag large and with an aero shape. Cheers |
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