|
|
Thread Tools | Display Modes |
#121
|
|||
|
|||
Creeping brake pad drag
On Monday, November 25, 2019 at 12:15:29 AM UTC, AMuzi wrote:
Sir Bradley Wiggins held 440W for an e n t i r e h o u r None of us did or could. Considering the average age of this forum, you'd better add "or should". -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 When I read that, my first thought was, "Hey, Wiggins is a latecomer to cycling, so there's hope for the rest of us yet." But, realistically... Andre Jute What if |
Ads |
#122
|
|||
|
|||
Creeping brake pad drag
On Sun, 24 Nov 2019 19:14:07 -0800 (PST), Sir Ridesalot
wrote: On Sunday, 24 November 2019 21:41:56 UTC-5, John B. wrote: On Sun, 24 Nov 2019 15:32:56 -0800 (PST), Sir Ridesalot wrote: On Sunday, 24 November 2019 18:03:26 UTC-5, wrote: On Sunday, November 24, 2019 at 11:59:10 PM UTC+1, Frank Krygowski wrote: On Sunday, November 24, 2019 at 3:33:45 PM UTC-5, Sir Ridesalot wrote: On Sunday, 24 November 2019 15:14:40 UTC-5, Duane wrote: You’re arguing with people that had the same sort of argument about brifters. Some people still argue that Brifters or Ergos aren't needed on ANY bicycle. "Needed"? I'd say brifters are needed to be competitive in a criterium race. They're often, but not always, needed to be competitive in the final sprint of a road race. When else are they "needed"? I wonder how heated the arguments would have been had the internet been around when the transition from wooden frames or from wooden wheels to metal ones or from solid rubber tires to pneumatic tires? When pneumatic tires were introduced, it became impossible to win a race on solid tires. The difference in rolling resistance was that dramatic. So was the difference in comfort. The same can be said about multiple gears. Very soon, everybody saw the advantages and knew the benefits outweighed the detriments. But since then, returns on technology have diminished. The benefits of most innovations since, oh, 2000 or so are barely measurable in most situations. - Frank Krygowski I came across this video: https://www.youtube.com/watch?v=1mJ06mro5fw Lou So the differences between a retro bike with modern kit and a modern bike with modern kit are @25hph 8 watts, @35 kph 21 Watts, and @45 kph 25 Watts. I'm not up on the Watts measurements so must ask, just how significant are those increases? Cheers https://www.cyclinganalytics.com/blo...output-compare FTP, or functional threshold power, is nominally the power output that can be sustained for one hour. Male Riders 49% of people have an FTP below 260W. 44.3% of people have an FTP of 270W or more. 6.7% of people have an FTP between 260W and 270W. FTP per kg of body weight 48.6% of people have an FTP below 3.4W/kg. 42.1% of people have an FTP of 3.6W/kg or more. 9.3% of people have an FTP between 3.4W/kg and 3.6W/kg. -- cheers, John B. Still hasn't answered if those increases I posted from the video are significant increases. Are they? Cheers Look at http://bikecalculator.com/index.html Which seems to show that: Based on a 1 hour effort of 259 watts on level ground, body weight 63 kg and bike weight 9 kg. To ride at 259 watts would equate to a speed of 35.17 kph at 259+12=267 watts = 35.57 at 259+21=280 watts = 36.19 at 259+45=304 watts = 37.29 I'm not sure how accurate these charts are but they should be indicative. -- cheers, John B. |
#123
|
|||
|
|||
Creeping brake pad drag
On 11/24/2019 7:04 PM, Duane wrote:
I have 11 speed SRAM and it works well. But honestly a typical 105 setup today is light years ahead of the stuff we rode in the old days with friction shifters and toe clips. Anyone can argue that new tech isn’t necessary. Seems silly. It probably depends on your personal definition of "necessary." For some people, biking "necessary" is the same as a teenage girl's definition when her mom takes her to the mall: "Mom, _everyone_ has that style! I've _got_ to have it! It's _necessary_!!" For me, "necessary" means something more like "I'd be unable to ride a bike without it. Or at least, riding without it would be a terrible experience." -- - Frank Krygowski |
#124
|
|||
|
|||
Creeping brake pad drag
Frank Krygowski wrote:
On 11/24/2019 8:08 PM, Sir Ridesalot wrote: So, just how much difference do those wattage differences from the video and which numbers I posted make in real life? I just ran some numbers. Lou can check me, but here's what I got. I fitted an equation to the "modern kit, modern bike" curve - the one that said 25kph takes only 79 Watts (not counting rolling resistance and drivetrain friction). The equation I got was Power = 0.0097 * speed ^ 2.7918 The "retro" bike took 87 Watts to go 25kph. So I backsolved to find out what speed the "modern" bike would go with 87 Watts. I came up with 26.05 kph. In other words, if you ditched your "retro" bike with round tubes, square section rims, old style handlebars, etc. and spent the money on a super-sleek aero modern bike, a 25kph rider would be able to go 26 kph. In miles per hour, that bike would take a 15.5 mph rider all the way up to 16.1 mph. Roughly half a mile per hour faster. I note that you get almost as much benefit switching from wrinkled wool clothing to an aero racing suit. So anyone NOT riding in a super-sleek racing suit should first buy one of those and carefully measure how much difference it makes on your normal rides. You can probably get a set of race clothes for a hundred bucks. See for yourself what that much difference feels like before you spend $2000+ on a full aero bike. Stripping most of the math away, on a bike, power is proportional to CdA times speed cubed. Therefore, a 10% improvement in CdA buys you a 3% increase in speed (the example in the GCN video). More importantly, the CdA of the bike is mostly overshadowed by that of the rider (CdA is actually coefficient of drag (Cd) times area (A), and the average cyclist has way more frontal area than their bike). So, as the GCN video stated, changes in rider CdA can be both larger and cheaper than the corresponding changes in bike CdA, but if you’ve already done that and are losing by smallish increments, the aero bike will buy you those smallish increments, and in the specialized case of coasting down a steep hill, reduction in aero drag can buy you temporary power increases of an astounding magnitude. |
#126
|
|||
|
|||
Creeping brake pad drag
On Monday, November 25, 2019 at 12:32:59 AM UTC+1, Sir Ridesalot wrote:
On Sunday, 24 November 2019 18:03:26 UTC-5, wrote: On Sunday, November 24, 2019 at 11:59:10 PM UTC+1, Frank Krygowski wrote: On Sunday, November 24, 2019 at 3:33:45 PM UTC-5, Sir Ridesalot wrote: On Sunday, 24 November 2019 15:14:40 UTC-5, Duane wrote: You’re arguing with people that had the same sort of argument about brifters. Some people still argue that Brifters or Ergos aren't needed on ANY bicycle. "Needed"? I'd say brifters are needed to be competitive in a criterium race. They're often, but not always, needed to be competitive in the final sprint of a road race. When else are they "needed"? I wonder how heated the arguments would have been had the internet been around when the transition from wooden frames or from wooden wheels to metal ones or from solid rubber tires to pneumatic tires? When pneumatic tires were introduced, it became impossible to win a race on solid tires. The difference in rolling resistance was that dramatic. So was the difference in comfort. The same can be said about multiple gears. Very soon, everybody saw the advantages and knew the benefits outweighed the detriments. But since then, returns on technology have diminished. The benefits of most innovations since, oh, 2000 or so are barely measurable in most situations. - Frank Krygowski I came across this video: https://www.youtube.com/watch?v=1mJ06mro5fw Lou So the differences between a retro bike with modern kit and a modern bike with modern kit are @25hph 8 watts, @35 kph 21 Watts, and @45 kph 25 Watts.. I'm not up on the Watts measurements so must ask, just how significant are those increases? Cheers I ride with a power meter for two years now so I think I got a feeling about numbers. For me from my experience: recovery ride 100-110 Watts, average speed about 25-26 km/hr, relative easy ride 140-150, Watts average speed about 28-29 km/hr average ride 180-190 Watts, average speed about 30-31 km/hr pushing really hard 200-210, average speed about 32-33 km/hr. All flat terrain and moderate temperature and wind concitions. So 15 -20 Watt increase in average power is very significant in intensity. Lou |
#127
|
|||
|
|||
Creeping brake pad drag
On 11/24/2019 10:15 PM, Frank Krygowski wrote:
On 11/24/2019 7:04 PM, Duane wrote: I have 11 speed SRAM and it works well. But honestly a typical 105 setup today is light years ahead of the stuff we rode in the old days with friction shifters and toe clips. Anyone can argue that new tech isn’t necessary. Seems silly. It probably depends on your personal definition of "necessary." For some people, biking "necessary" is the same as a teenage girl's definition when her mom takes her to the mall: "Mom, _everyone_ has that style! I've _got_ to have it! It's _necessary_!!" For me, "necessary" means something more like "I'd be unable to ride a bike without it. Or at least, riding without it would be a terrible experience." The line is very personal and dependent on taste more than engineering analysis. I'm riding around on a bog simple fixie yet you 'need' those complex gear choices. For another guy 2x12 suits his needs better than his old 3x10 for reasons you may not appreciate but they are real for him. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#128
|
|||
|
|||
Creeping brake pad drag
On Monday, November 25, 2019 at 4:57:17 AM UTC+1, Frank Krygowski wrote:
On 11/24/2019 8:08 PM, Sir Ridesalot wrote: So, just how much difference do those wattage differences from the video and which numbers I posted make in real life? I just ran some numbers. Lou can check me, but here's what I got. I fitted an equation to the "modern kit, modern bike" curve - the one that said 25kph takes only 79 Watts (not counting rolling resistance and drivetrain friction). The equation I got was Power = 0.0097 * speed ^ 2.7918 The "retro" bike took 87 Watts to go 25kph. So I backsolved to find out what speed the "modern" bike would go with 87 Watts. I came up with 26.05 kph. In other words, if you ditched your "retro" bike with round tubes, square section rims, old style handlebars, etc. and spent the money on a super-sleek aero modern bike, a 25kph rider would be able to go 26 kph. In miles per hour, that bike would take a 15.5 mph rider all the way up to 16.1 mph. Roughly half a mile per hour faster. I note that you get almost as much benefit switching from wrinkled wool clothing to an aero racing suit. So anyone NOT riding in a super-sleek racing suit should first buy one of those and carefully measure how much difference it makes on your normal rides. You can probably get a set of race clothes for a hundred bucks. See for yourself what that much difference feels like before you spend $2000+ on a full aero bike. -- - Frank Krygowski 1. no flappy clothes, 2. position on your bike, 3. better tires, 4. aero wheels, 5. aero bike Lou |
#129
|
|||
|
|||
Creeping brake pad drag
John B. writes:
On Sun, 24 Nov 2019 14:09:57 -0500, Radey Shouman wrote: John B. writes: On Sat, 23 Nov 2019 17:38:47 -0800 (PST), Sir Ridesalot wrote: On Saturday, 23 November 2019 20:12:07 UTC-5, John B. wrote: On Sat, 23 Nov 2019 16:30:21 -0800 (PST), Sir Ridesalot wrote: On Saturday, 23 November 2019 18:43:26 UTC-5, John B. wrote: On Sat, 23 Nov 2019 13:58:10 -0800 (PST), Frank Krygowski wrote: On Saturday, November 23, 2019 at 3:01:51 PM UTC-5, jbeattie wrote: On Saturday, November 23, 2019 at 9:37:21 AM UTC-8, Frank Krygowski wrote: In my view, putting immense complexity into a sealed black box does not make a system "simple." From a user standpoint, Di2 is very simple -- more simple than cables. No tension adjustment or lubrication, and no sticking after riding in muck. You have to charge it now and then -- and you can get fussy with programming (on bike, no computer necessary for certain settings). Electronic shifting is not an imperative, and it's expensive, but its a reasonable choice. Well, sure, everything is a reasonable choice for someone in some situations. But "no tension adjustment or lubrication"? I can't remember the last time I did a so-called tension adjustment on anything but the folding bike; and for whatever reason, that one seemed to settle down early this year. I think all my shift cables are lined with plastic, but for whatever reason, I don't ever seem to have to lubricate them. Well, except for where they pass through that open plastic channel under the bottom bracket of one bike, and that's only very rarely. Other lubrication? A Di2 derailleur still has mechanical pivoting joints, doesn't it? It's OK if someone wants to buy e-shifting. And given basic early adopter psychology, plus normal pride of ownership, it's a given that most who spend many hundreds of dollars for its tiny benefits will say it's worth it. But it seems obvious that 99.9999% of the world's cyclists - and even cycling enthusiasts - get along just fine with mechanical systems. This choice proves that, at best, bike technology is now way, way deep into diminishing returns. And I really do think there's an important difference between "simple to use because of incredible complexity built into a tiny box" and just plain "simple." That difference shows up when something goes wrong. - Frank Krygowski Ah, but Frank. You apparently understand, It is NEW! (and therefore obviously better :-) And USians apparently have an almost unlimited amount of disposable income - I read the other day that "shopping", i.e., going to the Mall, is now considered a form of entertainment. And, of course, one has to "keep up with the Jones" and one way to do it is to have a more expensive bicycle. (we have at least one bloke here who drops the casual mention of his $4,000 bike into the conversation at frequent intervals). What could be more up-market than electrical shifting. It is NEW, it is EXPENSIVE, I got it and you don't. What better reasons could possible be imagined for owning something? -- cheers, John B. Once it's totally perfected, widespread and trickled-down to mid-range groupsets; I can see electronic shifting getting popular with touring bicyclists. There would be no problems with cables. I have bicycles with downtube shifters and I have bicycles with downtube shifters AND tubular tires. MY road touring bicycle has Campagnolo 9-Speed Mirage Ergo levers on it. Ratcheting front shifter lever mechanism. Why? Because I like being able to have two hands on the handlebar when honking up a hill or riding in strong cross winds on my loaded touring bike. Franks and YMMV. I DO KNOW what works best for ME. Cheers Yes, I agree with you. When the price drops there will undoubtedly be a lot of bicycles sold with electric shifting. And, I'm sure that as more and more devices are developed/invented to eliminate any and all requirement for physical activity they will be marketed... and purchased. And yes, I hear you... Oh! I wouldn't have to take my hands off the handle bars. Really? Of course about the first thing that young people do after finally learning to ride a bicycle is practice riding "hands off". And the great improvement of electric shifting over what exists today seems to be that instead of flicking your first finger to shift you now can simply press the tip of your finger on a tiny button.... and for that you get to pay in the neighborhood of $1,500. Ohhh, such a bargain :-) One can only assume that the next step in eliminating any and all requirement for physical activity will be the electric bicycle.And, of course, it is: https://tinyurl.com/urcmt3r Electric bicycles are showing strong year-over-year growth in the U.S., with dollar sales growing by 95 percent in the 12 months ending July 2017, and unit sales up 96 percent, according to global information company The NPD Group. A $64.9 million category today, electric bicycle sales have nearly tripled over the last 36 months. -- cheers, John B. John, sometimes it's hard to tell if you're trying to be funny or obtuse. LOL VBEG Cynical. Here we have a two wheel vehicle that within living memory has largely been a toy for adolescents and the poor who either couldn't get a drivers license or were too poor to afford a "car" which suddenly blossom out into a $12,000 plastic thing, which the great bulk of the modern U.S. public wouldn't take if you paid them to. Mechanically a design that dates back to about 1850, some 170 years ago and a relatively simple designed then, with no major design changes from then to now. 1850? We must have read different histories. 1890 is more like it for a modern-looking safety bicycle, something that could reasonably be used for transportation by people of ordinary ability. Add twenty years or so to include people of ordinary means. The bicycle is, as much as the automobile, or the airplane, a product of the modern industrial age. A usable safety bicycle chain could no more have been manufactured in 1850 than a moon rocket. Well, you came closer than I did :-) https://www.liveabout.com/bikes-an-i...history-365776 A major breakthrough came in 1885 with John Kemp Starley's the creation of (or maybe "return to" is more accurate) a bike design that featured a rider perched much lower between two wheels of the same size, coupled with a sprocket and chain system that drove the bike from the rear wheel. This was the same basic "diamond frame" design still in use in today's bikes. As for making chains. As Starley designed and apparently built a bicycle using a chain it is apparent that chains suitable for use as a drive chain were in existence and as I doubt that they suddenly appeared out of the blue just in time for building the first modern bicycle I would suggest that they existed prior to 1885. Perhaps as early as 1850 :-) Big leather belts (scary things, really), and giant gear trains were widely used for industrial power transmission back around 1850. I'm sure there was a development process for roller chains that reaches back further than I might guess. I'll bet the early ones were big and clunky, hand made, and cost a minor fortune. I still think that chains so cheap that ordinary cyclists could throw them away had to wait for the twentieth century. In other words, you've been alive for well over half the history of the safety bicycle. How so? 1885 to 2019 is 134 years, twice 67. |
#130
|
|||
|
|||
Creeping brake pad drag
On Monday, 25 November 2019 09:27:59 UTC-5, wrote:
On Monday, November 25, 2019 at 4:57:17 AM UTC+1, Frank Krygowski wrote: On 11/24/2019 8:08 PM, Sir Ridesalot wrote: So, just how much difference do those wattage differences from the video and which numbers I posted make in real life? I just ran some numbers. Lou can check me, but here's what I got. I fitted an equation to the "modern kit, modern bike" curve - the one that said 25kph takes only 79 Watts (not counting rolling resistance and drivetrain friction). The equation I got was Power = 0.0097 * speed ^ 2.7918 The "retro" bike took 87 Watts to go 25kph. So I backsolved to find out what speed the "modern" bike would go with 87 Watts. I came up with 26.05 kph. In other words, if you ditched your "retro" bike with round tubes, square section rims, old style handlebars, etc. and spent the money on a super-sleek aero modern bike, a 25kph rider would be able to go 26 kph. In miles per hour, that bike would take a 15.5 mph rider all the way up to 16.1 mph. Roughly half a mile per hour faster. I note that you get almost as much benefit switching from wrinkled wool clothing to an aero racing suit. So anyone NOT riding in a super-sleek racing suit should first buy one of those and carefully measure how much difference it makes on your normal rides. You can probably get a set of race clothes for a hundred bucks. See for yourself what that much difference feels like before you spend $2000+ on a full aero bike. -- - Frank Krygowski 1. no flappy clothes, 2. position on your bike, 3. better tires, 4. aero wheels, 5. aero bike Lou One of the tests in that video was a retro bike with modern kit/clothing and another test was with a modern bike with modern kit/clothing. Thus whatever difference there was should have been due to the differences with the bicycles alone not the rider. I do wonder now though if they used the same tires on all of the bikes? Cheers |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
disc brake drag hayes circa 2003 | maceo | Techniques | 12 | April 11th 12 05:04 AM |
Creeping seatpost | Jack Myers | Techniques | 41 | March 9th 10 01:57 PM |
Drag Brake Setup?? | pdc | Unicycling | 2 | March 3rd 06 04:43 PM |
Tire creeping over rim | - | Techniques | 24 | October 4th 04 08:21 AM |
Hydraulic Drag Brake | gbarnes | Unicycling | 6 | August 6th 04 02:54 PM |