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#21
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 10, 3:05*pm, James wrote:
On Nov 11, 3:26*am, " wrote: Well, Frank, you do come off as being abusive. I think Frank talks down to so many students, he talks to everyone else the same. *It's annoying. *He knows not to whom he speaks. I think we now know what can be expected from Frank's students: http://articles.cnn.com/1999-09-30/t...eam?_s=PM:TECH DR |
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#22
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 9, 7:22*pm, Frank Krygowski
But there's more. *Does it all average out perfectly? *No - and the tiny differences in speed work to the disadvantage of the guy with lighter wheels! * You were getting close to the point I was trying to address here, and at least acknowledge that things do NOT average out perfectly. I have already addressed some other factors involved with this. DR |
#23
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Tue, 9 Nov 2010 22:13:36 -0800 (PST), DirtRoadie
wrote: On Nov 9, 10:32*pm, wrote: On Tue, 9 Nov 2010 19:31:13 -0800 (PST), DirtRoadie wrote: No. Let get right down to it. Skip the aerodynamics (unless you just want to make that a constant factor). [snip] Dear DR, Why do you think that you can skip the aerodynamics? I can do anything I want. But seriously, I wanted to focus on the wheel weight issue as related to power fluctuation in a pedal stroke and use a hypothetical where air resistance was a negligible portion of the retarding forces. DR Dear DR, At what speed is air resistance a negligible portion of the retarding forces? Cheers, Carl Fogel |
#24
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Wed, 10 Nov 2010 12:51:15 -0800 (PST), DirtRoadie
wrote: On Nov 10, 1:40*pm, Frank Krygowski wrote: On Nov 10, 1:13*am, DirtRoadie wrote: On Nov 9, 10:32*pm, wrote: On Tue, 9 Nov 2010 19:31:13 -0800 (PST), DirtRoadie wrote: No. Let get right down to it. Skip the aerodynamics (unless you just want to make that a constant factor). [snip] Dear DR, Why do you think that you can skip the aerodynamics? I can do anything I want. *But seriously, I wanted to focus on the wheel weight issue as related to power fluctuation in a pedal stroke and use a hypothetical where air resistance was a negligible portion of the retarding forces. So what part of my explanation did you not understand? Is it that you don't get that the inertia of a heavier wheel helps to maintain speed during a deceleration phase? You might want to address my reply to you rather than my reply to Carl. DR Dear DR, So what part of Frank's explanation did you not understand? Is it that you don't get that the inertia of a heavier wheel helps to maintain speed during a deceleration phase? Cheers, Carl Fogel |
#25
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 10, 11:26*am, "
wrote: On Nov 9, 10:01*am, Frank Krygowski wrote: Aero advantage of finger position is an example of something that never makes it out of the wind tunnel. *There are other advantages (whether aero, or weight, or inertia) that may possibly show up in a time trial or a match sprint, but get swamped by tactics and random events in any crit or road race. *And only the most extreme advantages (like going to a recumbent, or losing over five pounds) are going to be perceptible in non-competitive riding. We're back to the "swamped in the noise" argument. I maintain that the little advantages never go away. They might be small, very small, but they are still there, all the time. Like losing a pound, even from the 180lb rider + bike package yields whatever-- a second or three in a 40k ITT, is that the amount that's been demonstrated here? It's still real, even if people are foolishly clipping fingernails, etc. etc. It's "real" in the sense that it's detectable - that is, spend enough on a scale and you can measure tiny differences in weight. Spend enough on wind tunnel time and you can measure differences in aero drag. What's often not detectable is the benefit. You can't find the benefit of these tiny "improvements" in race results, or in records of average race speeds. If that information were available, I'm sure someone would have posted it by now - they'd link to an article showing that (for example) Milan-San Remo speeds have increased notably over the years because of bike technology. Except the article "Are Modern Bikes Faster?" in the Summer 2010 issue of Bicycle Quarterly shows that those speeds have not increased. Since about 1965, they've had no upward trend. And that's despite _other_ improvements in training techniques, nutrition, and who knows what chemicals in the riders' blood, etc.! Isn't it obvious that _some_ level of theoretical advantage must disappear into the noise? *If not, racers would be shaving their entire bodies. Well, that's another one of your rhetorical devices.... It's a serious question. People are telling me "No improvement is too tiny to matter!" Then when I say "Why not shave their heads?" people say "Don't be silly. That improvement doesn't matter." But there really have been wind tunnel tests evaluating the effect of hair. It obviously has to have some drag, even under a helmet. Same question applies to drilled components to save weight, and lots of other out-of-fashion "improvements." For instance, there was a racer here back in the day, a guy who won "something national on the track" against the names of the day-- attesting to "the motor"; he certainly had one. But something I used to see him do in races, consistently, was to be the only guy in the pack (that I could see at the moment) who was *not* pedaling, and sometimes, the only one not pedaling hard, while we were flying along. That's not "equipment aero" but it sure is aero, and it's real. He was really good at sniffing out a draft, and he did it without causing crashes, too, BTW. That mindset, in addition to the "little details" is what, IMHO, the smart racers do. Do you realize you're agreeing with what I wrote? I said it's better to spend the money on coaching, and spend the effort on learning tactics. It would probably make FAR more difference than taking 100 grams off your wheels. I know, and have known, members of the racing community. *As I said, I was on a ride with two of them not long ago. *One was saying "I'm thinking about trying those ceramic bearings for my crank." *Nice guys, but that's not saying much for their technical judgment. The ceramic bearing thing ran its course (semi-intentional!) around here. Then it's yet another example of something that was fashionable for a while ("No advantage is too tiny!") but then became out of fashion. ("Oh, those bearings don't matter.") There are better ways to figure this stuff out than by trial and error, you know. D-y, it wasn't intended to be abusive - any more, I suppose, than your phrase "which is usual for you." Well, Frank, you do come off as being abusive. What can I say? I can say it's apparently in the eye of certain beholders. Within the past two months, I've gotten e-mail from a rather notable poster, who said he tremendously enjoys my posts and hopes I stick around. Another very notable contributor e-mailed to call me one of the most polite people posting here. (Granted, he was saying it in the context of "Don't bother responding to Bill Sornson.") I've had people ask permission to use what I've written in these discussion groups. Obviously, not everyone shares your views. I'll also note that in my first post on this thread, when I said "the theoretical benefit is not great," DirtRoadie (whoever he is) responded with a super-sarcastic post: "Yes, by all means. Let's wipe away any thought of technical discussion because one person's opinion chooses to 'skip the details' and thereby deem any changes (improvements OR dead ends) unworthy. How is your abacus connected to the web?" Because of my profession, I'm used to discussing technical things in detail. In that first post of mine, I described a thought process that is often used: examine the limits, to see the maximum possible benefit, as an aid to judgment. It drew immediate ridicule. Yet you didn't see fit to chide DR for that. So you'll pardon me, I hope, if I don't kowtow to your judgments regarding my civility. - Frank Krygowski |
#26
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 10, 3:51*pm, DirtRoadie wrote:
On Nov 10, 1:40*pm, Frank Krygowski wrote: So what part of my explanation did you not understand? Is it that you don't get that the inertia of a heavier wheel helps to maintain speed during a deceleration phase? You might want to address my reply to you rather than my reply to Carl. I read your reply to me. I couldn't tell what part of my detailed explanation you were unable to understand. You wanted (for some reason) to discount aerodynamics, which I did. It still doesn't produce an advantage for the lighter wheels, vs. same total weight, while either climbing or riding level at constant speed. Now: Do you not understand that a heavier wheelset helps maintain forward speed during a deceleration phase of the pedal stroke? Is that your problem? Despite your rather childish insults, I'm willing to clear it up for you if you ask specific questions. Or specifically point out what you think I got wrong. - Frank Krygowski |
#27
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On 11/10/2010 4:10 PM, DirtRoadie WHO? wrote:
On Nov 10, 3:05 pm, wrote: On Nov 11, 3:26 am, wrote: Well, Frank, you do come off as being abusive. I think Frank talks down to so many students, he talks to everyone else the same. It's annoying. He knows not to whom he speaks. I think we now know what can be expected from Frank's students: http://articles.cnn.com/1999-09-30/t...eam?_s=PM:TECH DR "jim", is that you? -- Tom Sherman - 42.435731,-83.985007 I am a vehicular cyclist. |
#28
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On 11/10/2010 1:44 PM, thirty-six wrote:
Rear wheel instability and inadequate chain lubrication are typically the largest energy saps when climbing [...] Damn, and I thought it was working against gravity! -- Tom Sherman - 42.435731,-83.985007 I am a vehicular cyclist. |
#29
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 10, 10:47*pm, Tom Sherman °_°
wrote: On 11/10/2010 1:44 PM, thirty-six wrote: Rear wheel instability and inadequate chain lubrication are typically the largest energy saps when climbing [...] Damn, and I thought it was working against gravity! There are planets where gravity is quite weak, apparently. Unfortunately, you and I don't live on one. - Frank Krygowski |
#30
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 10, 8:05*pm, Frank Krygowski wrote:
It's "real" in the sense that it's detectable - that is, spend enough on a scale and you can measure tiny differences in weight. *Spend enough on wind tunnel time and you can measure differences in aero drag. Dr. James Martin didn't feel the need for a wind tunnel. He measured a time difference on the road, after doubting modeling predictions. Aero wheels made a huge difference. What's often not detectable is the benefit. Well, that's your old song, sure enough. *You can't find the benefit of these tiny "improvements" in race results, or in records of average race speeds. *If that information were available, I'm sure someone would have posted it by now - they'd link to an article showing that (for example) Milan-San Remo speeds have increased notably over the years because of bike technology. Milan San-Remo is a very long one-day race, which is held very early in the year-- first event on the pro racing calendar, I believe. There are a few places where getting over a hill or a combination of hills in front is "everything" IRT winning (or "not losing") that race. IOW, overall speed is much, much less a factor for that race than is being in the right place at the right time, with a motor. The TdF, raced over many days and with several different "prizes" as stake, from GC to Green Jersey to Polka Dot to Young Rider, plus Team, tend to make these stages more truly competitive than MSR. Just a for- instance, but in an article in ProCycling: http://www.fredericgrappe.com/media/revues/manipvelo.pdf the general content of which applies quite well IMHO to this thread, Laurent Fignon's winning average for the 1983 TdF is quoted as being 36.23kph, while Carlos Sastre's '08 average winning speed is given as 40.492kph. Noted, the '08 Lanterne Rouge, one Vanservant, rode significantly faster than Fignon's 1983 average, at 38.76kph. Why, Frank, I'd think one might fairly accuse you of cherry-picking data here! Except the article "Are Modern Bikes Faster?" in the Summer 2010 issue of Bicycle Quarterly shows that those speeds have not increased. Since about 1965, they've had no upward trend. *And that's despite _other_ improvements in training techniques, nutrition, and who knows what chemicals in the riders' blood, etc.! Again, there is relevant discussion in the ProCycling article. "Offered (by me) as such". Isn't it obvious that _some_ level of theoretical advantage must disappear into the noise? *If not, racers would be shaving their entire bodies. Well, that's another one of your rhetorical devices.... It's a serious question. I don't see it that way. It's a form of ridicule. *People are telling me "No improvement is too tiny to matter!" That's not the way I have phrased it. Are you trying to put words in my mouth? *Then when I say "Why not shave their heads?" people say "Don't be silly. *That improvement doesn't matter." Well, we can see that is a rhetorical device because all heads are helmeted in racing and have been for quite some time. Then we are presented with the picture of a bunch of funny-looking men who stupidly shave their heads to no avail. That's just ridicule and you indulge often. But there really have been wind tunnel tests evaluating the effect of hair. *It obviously has to have some drag, even under a helmet. "Obviously"? I didn't think Men of Science were supposed to go there, Frank. Same question applies to drilled components to save weight, and lots of other out-of-fashion "improvements." Oh my goodness, drag some dino bones out of the tar pits of history and say "Look! How stupid they were!" For instance, there was a racer here back in the day, a guy who won "something national on the track" against the names of the day-- attesting to "the motor"; he certainly had one. But something I used to see him do in races, consistently, was to be the only guy in the pack (that I could see at the moment) who was *not* pedaling, and sometimes, the only one not pedaling hard, while we were flying along. That's not "equipment aero" but it sure is aero, and it's real. He was really good at sniffing out a draft, and he did it without causing crashes, too, BTW. That mindset, in addition to the "little details" is what, IMHO, the smart racers do. Do you realize you're agreeing with what I wrote? No, I'm not agreeing with "what you wrote". *I said it's better to spend the money on coaching, and spend the effort on learning tactics. *It would probably make FAR more difference than taking 100 grams off your wheels. That's an "old story"; this guy was a hustler from the Old School and had the latest/greatest gear of the time. Like many (most, most all) the successful racers and fast retired racers of today, those who more tend to make their money via professional employment, they look for advantages wherever advantages can be found. I know, and have known, members of the racing community. *As I said, I was on a ride with two of them not long ago. *One was saying "I'm thinking about trying those ceramic bearings for my crank." *Nice guys, but that's not saying much for their technical judgment. The ceramic bearing thing ran its course (semi-intentional!) around here. Then it's yet another example of something that was fashionable for a while ("No advantage is too tiny!") but then became out of fashion. ("Oh, those bearings don't matter.") *There are better ways to figure this stuff out than by trial and error, you know. No, I don't "know" that trial-and-error is an inferior way to "figure things out", when it comes to using "things" in the field. Even today, with computer-aided design, they build the airplanes via "best guesses" and then see if it will fly-- and fix the problems that come up along the way. D-y, it wasn't intended to be abusive - any more, I suppose, than your phrase "which is usual for you." Well, Frank, you do come off as being abusive. What can I say? I can say it's apparently in the eye of certain beholders. *Within the past two months, I've gotten e-mail from a rather notable poster, who said he tremendously enjoys my posts and hopes I stick around. Another very notable contributor e-mailed to call me one of the most polite people posting here. *(Granted, he was saying it in the context of "Don't bother responding to Bill Sornson.") *I've had people ask permission to use what I've written in these discussion groups. Obviously, not everyone shares your views. Defensive. Some share, some don't. Some, I'm sure, like it when you dish on me and others, from a personal standpoint. You're still being abusive. It's the person who is being dumped on who understands best, of course. Obviously, I can handle it; don't like it but such is life and on the ng's g. I'll also note that in my first post on this thread, when I said "the theoretical benefit is not great," DirtRoadie (whoever he is) responded with a super-sarcastic post: "Yes, by all means. Let's wipe away any thought of technical discussion because one person's opinion chooses to 'skip the details' and thereby deem any changes (improvements OR dead ends) unworthy. *How is your abacus connected to the web?" Sounds like he got one in. there. Doesn't mean you can't take the high, or at least higher, ground. Because of my profession, I'm used to discussing technical things in detail. *In that first post of mine, I described a thought process that is often used: examine the limits, to see the maximum possible benefit, as an aid to judgment. *It drew immediate ridicule. *Yet you didn't see fit to chide DR for that. I never said I was perfect. So you'll pardon me, I hope, if I don't kowtow to your judgments regarding my civility. I didn't "demand a kow-tow" in the first place. I think your civility is lacking and, as I've said before, I think you're used to talking down to students and carry that 'tude into this ng. Calling them as I see them. --D-y |
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