#21
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Question for Frank
On Tuesday, November 1, 2016 at 7:25:38 AM UTC-4, John B Slocomb wrote:
I have the feeling that there is a matter in definition here. Is "aero" a term used only for those with their back perfectly flat, or can it apply to someone that is leaning forward only 45 degrees? I've found that simply moving my hands to the drops with my elbows still straight increases coasting speed on one particular kill by just about 1 kph. Is that not "aero"? "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. A few years ago, there were some wind tunnel test results reported in _Bicycle Quarterly_. Of course, they've appeared in other sources as well - but those in BQ concentrated on fairly normal-looking bikes, not time trial machines or the like. One salient fact was that drag coefficent seemed unaffected by rider posture. Any aero benefit came (almost?) entirely from reductions in frontal area. If true, that's good news, because it's far easier to notice one's own changes in frontal area. It should be obvious, for example, whether one's elbows are sticking out in the wind or not. - Frank Krygowski |
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#22
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Question for Frank
On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski
wrote: On Tuesday, November 1, 2016 at 7:25:38 AM UTC-4, John B Slocomb wrote: I have the feeling that there is a matter in definition here. Is "aero" a term used only for those with their back perfectly flat, or can it apply to someone that is leaning forward only 45 degrees? I've found that simply moving my hands to the drops with my elbows still straight increases coasting speed on one particular kill by just about 1 kph. Is that not "aero"? "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. A few years ago, there were some wind tunnel test results reported in _Bicycle Quarterly_. Of course, they've appeared in other sources as well - but those in BQ concentrated on fairly normal-looking bikes, not time trial machines or the like. One salient fact was that drag coefficent seemed unaffected by rider posture. Any aero benefit came (almost?) entirely from reductions in frontal area. If true, that's good news, because it's far easier to notice one's own changes in frontal area. It should be obvious, for example, whether one's elbows are sticking out in the wind or not. - Frank Krygowski But one must shave the legs :-) |
#23
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Question for Frank
On Tuesday, November 1, 2016 at 7:15:50 PM UTC-4, John B Slocomb wrote:
On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski wrote: On Tuesday, November 1, 2016 at 7:25:38 AM UTC-4, John B Slocomb wrote: I have the feeling that there is a matter in definition here. Is "aero" a term used only for those with their back perfectly flat, or can it apply to someone that is leaning forward only 45 degrees? I've found that simply moving my hands to the drops with my elbows still straight increases coasting speed on one particular kill by just about 1 kph. Is that not "aero"? "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. A few years ago, there were some wind tunnel test results reported in _Bicycle Quarterly_. Of course, they've appeared in other sources as well - but those in BQ concentrated on fairly normal-looking bikes, not time trial machines or the like. One salient fact was that drag coefficent seemed unaffected by rider posture. Any aero benefit came (almost?) entirely from reductions in frontal area. If true, that's good news, because it's far easier to notice one's own changes in frontal area. It should be obvious, for example, whether one's elbows are sticking out in the wind or not. - Frank Krygowski But one must shave the legs :-) There was a study done, iirc not that long ago, that showed a pretty good aero asdvantage with shaved legs. In fact those that did the study were surprised at how much of an advantage sghaved legs gave. Cheers |
#24
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Question for Frank
On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski
wrote: "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. And sitting up straight and spreading yourself out is a good way to brake when coasting down a hill. -- Joy Beeson joy beeson at comcast dot net http://wlweather.net/PAGEJOY/ |
#25
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Question for Frank
On Wed, 02 Nov 2016 23:02:14 -0400, Joy Beeson
wrote: On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski wrote: "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. And sitting up straight and spreading yourself out is a good way to brake when coasting down a hill. Yes, I think Frank mentioned that. Downhill speed builds up until the aerodynamic drag equals the effect of gravity. Based on sky divers anecdotes that is something like 100 mph. Whoopee! |
#26
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Question for Frank
On Tuesday, November 1, 2016 at 7:21:08 PM UTC-4, Sir Ridesalot wrote:
On Tuesday, November 1, 2016 at 7:15:50 PM UTC-4, John B Slocomb wrote: On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski wrote: On Tuesday, November 1, 2016 at 7:25:38 AM UTC-4, John B Slocomb wrote: I have the feeling that there is a matter in definition here. Is "aero" a term used only for those with their back perfectly flat, or can it apply to someone that is leaning forward only 45 degrees? I've found that simply moving my hands to the drops with my elbows still straight increases coasting speed on one particular kill by just about 1 kph. Is that not "aero"? "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. A few years ago, there were some wind tunnel test results reported in _Bicycle Quarterly_. Of course, they've appeared in other sources as well - but those in BQ concentrated on fairly normal-looking bikes, not time trial machines or the like. One salient fact was that drag coefficent seemed unaffected by rider posture. Any aero benefit came (almost?) entirely from reductions in frontal area. If true, that's good news, because it's far easier to notice one's own changes in frontal area. It should be obvious, for example, whether one's elbows are sticking out in the wind or not. - Frank Krygowski But one must shave the legs :-) There was a study done, iirc not that long ago, that showed a pretty good aero asdvantage with shaved legs. In fact those that did the study were surprised at how much of an advantage sghaved legs gave. Cheers those reading the study were surprised how much leverage the advantage gave the study |
#27
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Question for Frank
On 11/3/2016 7:30 AM, John B Slocomb wrote:
On Wed, 02 Nov 2016 23:02:14 -0400, Joy Beeson wrote: On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski wrote: "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. And sitting up straight and spreading yourself out is a good way to brake when coasting down a hill. Yes, I think Frank mentioned that. Downhill speed builds up until the aerodynamic drag equals the effect of gravity. Based on sky divers anecdotes that is something like 100 mph. Whoopee! It depends on the slope, of course (and wind direction, to a much lesser degree). And weight of the bike+rider. I led a fairly hilly club ride last week. Using my aero bars on the downhills, I generally out-coast most members of our club. But one new member of our club was blasting past me on every downhill, despite sitting upright and using straight handlebars. His secret? I suspect he weighs over 250 pounds. (I give him great credit for keeping up on the uphills!) -- - Frank Krygowski |
#28
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Question for Frank
On Thu, 3 Nov 2016 11:10:56 -0400, Frank Krygowski
wrote: On 11/3/2016 7:30 AM, John B Slocomb wrote: On Wed, 02 Nov 2016 23:02:14 -0400, Joy Beeson wrote: On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski wrote: "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. And sitting up straight and spreading yourself out is a good way to brake when coasting down a hill. Yes, I think Frank mentioned that. Downhill speed builds up until the aerodynamic drag equals the effect of gravity. Based on sky divers anecdotes that is something like 100 mph. Whoopee! It depends on the slope, of course (and wind direction, to a much lesser degree). And weight of the bike+rider. I led a fairly hilly club ride last week. Using my aero bars on the downhills, I generally out-coast most members of our club. But one new member of our club was blasting past me on every downhill, despite sitting upright and using straight handlebars. His secret? I suspect he weighs over 250 pounds. (I give him great credit for keeping up on the uphills!) Yes, weight certainly does help in the mountains. About half the time :-) |
#29
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Question for Frank
John B Slocomb writes:
On Thu, 3 Nov 2016 11:10:56 -0400, Frank Krygowski wrote: On 11/3/2016 7:30 AM, John B Slocomb wrote: On Wed, 02 Nov 2016 23:02:14 -0400, Joy Beeson wrote: On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski wrote: "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. And sitting up straight and spreading yourself out is a good way to brake when coasting down a hill. Yes, I think Frank mentioned that. Downhill speed builds up until the aerodynamic drag equals the effect of gravity. Based on sky divers anecdotes that is something like 100 mph. Whoopee! It depends on the slope, of course (and wind direction, to a much lesser degree). And weight of the bike+rider. I led a fairly hilly club ride last week. Using my aero bars on the downhills, I generally out-coast most members of our club. But one new member of our club was blasting past me on every downhill, despite sitting upright and using straight handlebars. His secret? I suspect he weighs over 250 pounds. (I give him great credit for keeping up on the uphills!) Yes, weight certainly does help in the mountains. About half the time :-) Half the *distance* you mean. Way less than half the *time*. -- |
#30
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Question for Frank
On Fri, 04 Nov 2016 11:13:58 -0400, Radey Shouman
wrote: John B Slocomb writes: On Thu, 3 Nov 2016 11:10:56 -0400, Frank Krygowski wrote: On 11/3/2016 7:30 AM, John B Slocomb wrote: On Wed, 02 Nov 2016 23:02:14 -0400, Joy Beeson wrote: On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski wrote: "Aero" is a vague word, of course. But IME moving from the drops to the aero bar causes a similar increase in speed, perhaps even more. And sitting up straight and spreading yourself out is a good way to brake when coasting down a hill. Yes, I think Frank mentioned that. Downhill speed builds up until the aerodynamic drag equals the effect of gravity. Based on sky divers anecdotes that is something like 100 mph. Whoopee! It depends on the slope, of course (and wind direction, to a much lesser degree). And weight of the bike+rider. I led a fairly hilly club ride last week. Using my aero bars on the downhills, I generally out-coast most members of our club. But one new member of our club was blasting past me on every downhill, despite sitting upright and using straight handlebars. His secret? I suspect he weighs over 250 pounds. (I give him great credit for keeping up on the uphills!) Yes, weight certainly does help in the mountains. About half the time :-) Half the *distance* you mean. Way less than half the *time*. Well, I suppose I was using the vernacular, i.e., the time I was in Belgrade, or the time I saw that ugly woman, or even the time I was in the mountains :-) |
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