#11
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Things to know
On Sunday, December 6, 2020 at 3:26:11 PM UTC-8, Mark J. wrote:
On 12/6/2020 2:17 PM, Mark Cleary wrote: So if you take a front road wheel and spin it by hand how long does yours spin before stopping? Today I check my front Ultegra bearings and they were fine the 10000 plus miles shows zero wear. I did pull the bearings and re-greased, cleaned them up but of course when you dump the while lithium grease back they look dirty again. Maybe should have used my marine grease but did not. In any case I spun the wheel afterward by hand the computer has it getting to 9mph and it spins about 45 seconds. I then went over to the other bike that has pretty much a front wheel with 105 hubs and simply spun that one. It manages to spin for a minute. Both smooth but I wonder if that means a damn thing? Deacon Mark I doubt the 15sec difference means much. Could be a difference in seal friction (if either of your hubs has the rubber cone-to-dust cover seals that used to be popular). Could be a minor difference in how tight you adjusted the cones. Both sound fine to me. Besides, I doubt we're very consistent with how hard we spin a wheel. What might be a finer measure of hub friction: Spin the wheel very slowly so that the wheel quits "turning over" and starts spinning/swinging back and forth as the heaviest point (usually either valve, reflector, or rim join, but not always) seeks bottom. Usually the wheel stops when the heaviest point is *near* bottom but not *at* bottom - the heavy point swings past bottom then stops, b/c friction overcomes the tiny bit that the weight is off-bottom. Spin a few times and compare the distance of the shortest "swing," and how close to bottom the heavy point is. Less friction will make the wheel continue to oscillate with shorter swings. Higher friction will stop the wheel when the swings are still kinda large. Of course a better-balanced wheel will confound all this. PS - just so long as you get *some* oscillation before the wheel stops, you're probably doing just fine. With reasonably good components the total loss to rolling resistance in the bottom bracket, wheels and tires is about 15-20 watts. While this might make a difference to a pro in a TT, you or I are very unlikely to even notice that. We generate perhaps 300-400 watts full time power. The human body isn't built to notice 10% losses unless you have been riding well above your FTP for some time and have been forced to slow up. Then while you can tell that you're going slower you simply couldn't tell the source of the drag - whether bicycle or body exhaustion. |
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#12
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Things to know
On Sunday, December 6, 2020 at 4:03:53 PM UTC-8, AMuzi wrote:
On 12/6/2020 5:45 PM, Frank Krygowski wrote: On 12/6/2020 6:28 PM, AMuzi wrote: On 12/6/2020 4:17 PM, Mark Cleary wrote: So if you take a front road wheel and spin it by hand how long does yours spin before stopping? Today I check my front Ultegra bearings and they were fine the 10000 plus miles shows zero wear. I did pull the bearings and re-greased, cleaned them up but of course when you dump the while lithium grease back they look dirty again. Maybe should have used my marine grease but did not. In any case I spun the wheel afterward by hand the computer has it getting to 9mph and it spins about 45 seconds. I then went over to the other bike that has pretty much a front wheel with 105 hubs and simply spun that one. It manages to spin for a minute. Both smooth but I wonder if that means a damn thing? Deacon Mark No idea.Too many variables. Heavier rim/tire spins longer (you aren't measuring your energy input) Properly adjusted bearing will spin longer than a tight one.  A bearing adjusted too slack will spin pretty well with no load but will wear quickly in normal service. Before service, your lubricant may be a bit dried and pushed away from the balls. Fresh lubricant is 'in the way' and lubricants cover quite a range of viscosities. I'm curious about "they look dirty again". That may mean you didn't clean the hubshell or threads on the axle etc. That sort of problem can lead to really fast wear if the crud previously pushed to the corners is now running in your lubricant. I agree with all of what Andrew said, including cleaning things thoroughly. When comparing two wheels, the weight of the rim, tube and tire make a difference, since heavier flywheels spin longer, other things being equal. I suppose even different spokes could affect things - although ... I remember years ago when I was playing with aerodynamics, I did your test with my bike's stock wheel. Then I replaced the spokes with bladed spokes and tested again. I'd changed nothing else in the wheel. I knew that the lesser air resistance of the spokes would allow it to coast longer, but I wanted to see how much longer. Except it didn't. The wheel stopped sooner with the bladed spokes. Not much sooner, but multiple trials gave consistent results. I can't say why. The important thing to remember is, bearing friction is practically negligible, unless things are really terrible in there. It's a minuscule portion of the forces holding you back when you ride. It's kind of like clipping your fingernails to save weight. Yes, I'm with you mostly. As with so may things, sometimes we don't know what it is we don't know. In my small understanding of aerodynamics for low speeds (sub-mach = bicycles, autos) the effects change dramatically sometimes. Aero spokes may well give an advantage at 30~35mph (race speeds) imperceptible in your test. I don't know but it's very possible. Fashionable rear spoilers on autos are mostly geegaws but can be very useful at 100, 120mph and up. My own Corsa drops noticeably at just over 85mph when using the front air dam. A guy driving it below 65mph would never know that. People that aren't wheel builders don't understand that drag actually increases compared to round spokes unless all of the aero spokes are perfectly aligned and that is seldom the case with amateur wheel builders. You can test this for yourself by twisting a few aero spokes out of alignment. One of the things that those Chinese aero wheel builders do is a remarkable job of perfectly aligning the aero spokes. |
#13
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Things to know
Op maandag 7 december 2020 om 18:16:25 UTC+1 schreef :
On Sunday, December 6, 2020 at 3:26:11 PM UTC-8, Mark J. wrote: On 12/6/2020 2:17 PM, Mark Cleary wrote: So if you take a front road wheel and spin it by hand how long does yours spin before stopping? Today I check my front Ultegra bearings and they were fine the 10000 plus miles shows zero wear. I did pull the bearings and re-greased, cleaned them up but of course when you dump the while lithium grease back they look dirty again. Maybe should have used my marine grease but did not. In any case I spun the wheel afterward by hand the computer has it getting to 9mph and it spins about 45 seconds. I then went over to the other bike that has pretty much a front wheel with 105 hubs and simply spun that one. It manages to spin for a minute. Both smooth but I wonder if that means a damn thing? Deacon Mark I doubt the 15sec difference means much. Could be a difference in seal friction (if either of your hubs has the rubber cone-to-dust cover seals that used to be popular). Could be a minor difference in how tight you adjusted the cones. Both sound fine to me. Besides, I doubt we're very consistent with how hard we spin a wheel. What might be a finer measure of hub friction: Spin the wheel very slowly so that the wheel quits "turning over" and starts spinning/swinging back and forth as the heaviest point (usually either valve, reflector, or rim join, but not always) seeks bottom. Usually the wheel stops when the heaviest point is *near* bottom but not *at* bottom - the heavy point swings past bottom then stops, b/c friction overcomes the tiny bit that the weight is off-bottom. Spin a few times and compare the distance of the shortest "swing," and how close to bottom the heavy point is. Less friction will make the wheel continue to oscillate with shorter swings. Higher friction will stop the wheel when the swings are still kinda large. Of course a better-balanced wheel will confound all this. PS - just so long as you get *some* oscillation before the wheel stops, you're probably doing just fine. With reasonably good components the total loss to rolling resistance in the bottom bracket, wheels and tires is about 15-20 watts. While this might make a difference to a pro in a TT, you or I are very unlikely to even notice that. We generate perhaps 300-400 watts full time power. The human body isn't built to notice 10% losses unless you have been riding well above your FTP for some time and have been forced to slow up. Then while you can tell that you're going slower you simply couldn't tell the source of the drag - whether bicycle or body exhaustion. Make that around 150-200 W full time power. 300-400 W full time power is Pro level, and even they can't sustain that for 5-6 hours. Really you do notice 15-20 Watt loss. Lou |
#14
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Things to know
On Monday, December 7, 2020 at 11:21:40 AM UTC-6, wrote:
Op maandag 7 december 2020 om 18:16:25 UTC+1 schreef : On Sunday, December 6, 2020 at 3:26:11 PM UTC-8, Mark J. wrote: On 12/6/2020 2:17 PM, Mark Cleary wrote: So if you take a front road wheel and spin it by hand how long does yours spin before stopping? Today I check my front Ultegra bearings and they were fine the 10000 plus miles shows zero wear. I did pull the bearings and re-greased, cleaned them up but of course when you dump the while lithium grease back they look dirty again. Maybe should have used my marine grease but did not. In any case I spun the wheel afterward by hand the computer has it getting to 9mph and it spins about 45 seconds. I then went over to the other bike that has pretty much a front wheel with 105 hubs and simply spun that one. It manages to spin for a minute. Both smooth but I wonder if that means a damn thing? Deacon Mark I doubt the 15sec difference means much. Could be a difference in seal friction (if either of your hubs has the rubber cone-to-dust cover seals that used to be popular). Could be a minor difference in how tight you adjusted the cones. Both sound fine to me. Besides, I doubt we're very consistent with how hard we spin a wheel. What might be a finer measure of hub friction: Spin the wheel very slowly so that the wheel quits "turning over" and starts spinning/swinging back and forth as the heaviest point (usually either valve, reflector, or rim join, but not always) seeks bottom. Usually the wheel stops when the heaviest point is *near* bottom but not *at* bottom - the heavy point swings past bottom then stops, b/c friction overcomes the tiny bit that the weight is off-bottom. Spin a few times and compare the distance of the shortest "swing," and how close to bottom the heavy point is. Less friction will make the wheel continue to oscillate with shorter swings. Higher friction will stop the wheel when the swings are still kinda large. Of course a better-balanced wheel will confound all this. PS - just so long as you get *some* oscillation before the wheel stops, you're probably doing just fine. With reasonably good components the total loss to rolling resistance in the bottom bracket, wheels and tires is about 15-20 watts. While this might make a difference to a pro in a TT, you or I are very unlikely to even notice that. We generate perhaps 300-400 watts full time power. The human body isn't built to notice 10% losses unless you have been riding well above your FTP for some time and have been forced to slow up. Then while you can tell that you're going slower you simply couldn't tell the source of the drag - whether bicycle or body exhaustion. Make that around 150-200 W full time power. 300-400 W full time power is Pro level, and even they can't sustain that for 5-6 hours. Really you do notice 15-20 Watt loss. Lou I notice the greaser Shimano uses seems to be lighter than the stuff I had. It was almost clear and looked clean for sure. Then wiping the grease off and cleaning the races and ball bearings everything looks nice and shiny. Repacking the bearings then it looks like a bunch of balls in mash potatoes. I notice when spinning the wheel by hand is simply comes to a rest and does not oscillate and start going the other direction. I do have the computer magnet still on spoke so not weighted even. To set the pre load not much as you just push the cone back on and the cone holding tube. Then tighten at end with 5mm allen wrench but it is a set amount already in advance. Deacon mark |
#15
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Things to know
On Monday, December 7, 2020 at 10:08:40 AM UTC-8, wrote:
On Monday, December 7, 2020 at 11:21:40 AM UTC-6, wrote: Op maandag 7 december 2020 om 18:16:25 UTC+1 schreef : On Sunday, December 6, 2020 at 3:26:11 PM UTC-8, Mark J. wrote: On 12/6/2020 2:17 PM, Mark Cleary wrote: So if you take a front road wheel and spin it by hand how long does yours spin before stopping? Today I check my front Ultegra bearings and they were fine the 10000 plus miles shows zero wear. I did pull the bearings and re-greased, cleaned them up but of course when you dump the while lithium grease back they look dirty again. Maybe should have used my marine grease but did not. In any case I spun the wheel afterward by hand the computer has it getting to 9mph and it spins about 45 seconds. I then went over to the other bike that has pretty much a front wheel with 105 hubs and simply spun that one. It manages to spin for a minute. Both smooth but I wonder if that means a damn thing? Deacon Mark I doubt the 15sec difference means much. Could be a difference in seal friction (if either of your hubs has the rubber cone-to-dust cover seals that used to be popular). Could be a minor difference in how tight you adjusted the cones. Both sound fine to me. Besides, I doubt we're very consistent with how hard we spin a wheel. What might be a finer measure of hub friction: Spin the wheel very slowly so that the wheel quits "turning over" and starts spinning/swinging back and forth as the heaviest point (usually either valve, reflector, or rim join, but not always) seeks bottom. Usually the wheel stops when the heaviest point is *near* bottom but not *at* bottom - the heavy point swings past bottom then stops, b/c friction overcomes the tiny bit that the weight is off-bottom. Spin a few times and compare the distance of the shortest "swing," and how close to bottom the heavy point is. Less friction will make the wheel continue to oscillate with shorter swings. Higher friction will stop the wheel when the swings are still kinda large. Of course a better-balanced wheel will confound all this. PS - just so long as you get *some* oscillation before the wheel stops, you're probably doing just fine. With reasonably good components the total loss to rolling resistance in the bottom bracket, wheels and tires is about 15-20 watts. While this might make a difference to a pro in a TT, you or I are very unlikely to even notice that. We generate perhaps 300-400 watts full time power. The human body isn't built to notice 10% losses unless you have been riding well above your FTP for some time and have been forced to slow up. Then while you can tell that you're going slower you simply couldn't tell the source of the drag - whether bicycle or body exhaustion. Make that around 150-200 W full time power. 300-400 W full time power is Pro level, and even they can't sustain that for 5-6 hours. Really you do notice 15-20 Watt loss. Lou I notice the greaser Shimano uses seems to be lighter than the stuff I had. It was almost clear and looked clean for sure. Then wiping the grease off and cleaning the races and ball bearings everything looks nice and shiny. Repacking the bearings then it looks like a bunch of balls in mash potatoes. I notice when spinning the wheel by hand is simply comes to a rest and does not oscillate and start going the other direction. I do have the computer magnet still on spoke so not weighted even. To set the pre load not much as you just push the cone back on and the cone holding tube. Then tighten at end with 5mm allen wrench but it is a set amount already in advance. Deacon mark Maybe you need Dura Ace grease. https://tinyurl.com/y5udu5jz 105 grease is much slower. Sora grease is made out of tubular cement and should be avoided. Fun diversion. Back in the '70s, I was riding in this shop ride crypto-race, and one of the guys (who was struggling) looked over at me and said "I think I got Tubasti in my hubs." Make sure you do not have Tubasti in your hubs -- even if you put it in six zip-lock bags and lock it in a vault, it will find its way out. https://www.youtube.com/watch?v=TdUs...RetroAlexander -- Jay Beattie. |
#16
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Things to know
On Monday, December 7, 2020 at 12:49:52 PM UTC-6, jbeattie wrote:
On Monday, December 7, 2020 at 10:08:40 AM UTC-8, wrote: On Monday, December 7, 2020 at 11:21:40 AM UTC-6, wrote: Op maandag 7 december 2020 om 18:16:25 UTC+1 schreef : On Sunday, December 6, 2020 at 3:26:11 PM UTC-8, Mark J. wrote: On 12/6/2020 2:17 PM, Mark Cleary wrote: So if you take a front road wheel and spin it by hand how long does yours spin before stopping? Today I check my front Ultegra bearings and they were fine the 10000 plus miles shows zero wear. I did pull the bearings and re-greased, cleaned them up but of course when you dump the while lithium grease back they look dirty again. Maybe should have used my marine grease but did not. In any case I spun the wheel afterward by hand the computer has it getting to 9mph and it spins about 45 seconds. I then went over to the other bike that has pretty much a front wheel with 105 hubs and simply spun that one. It manages to spin for a minute. Both smooth but I wonder if that means a damn thing? Deacon Mark I doubt the 15sec difference means much. Could be a difference in seal friction (if either of your hubs has the rubber cone-to-dust cover seals that used to be popular). Could be a minor difference in how tight you adjusted the cones. Both sound fine to me. Besides, I doubt we're very consistent with how hard we spin a wheel. What might be a finer measure of hub friction: Spin the wheel very slowly so that the wheel quits "turning over" and starts spinning/swinging back and forth as the heaviest point (usually either valve, reflector, or rim join, but not always) seeks bottom. Usually the wheel stops when the heaviest point is *near* bottom but not *at* bottom - the heavy point swings past bottom then stops, b/c friction overcomes the tiny bit that the weight is off-bottom. Spin a few times and compare the distance of the shortest "swing," and how close to bottom the heavy point is. Less friction will make the wheel continue to oscillate with shorter swings. Higher friction will stop the wheel when the swings are still kinda large. Of course a better-balanced wheel will confound all this. PS - just so long as you get *some* oscillation before the wheel stops, you're probably doing just fine. With reasonably good components the total loss to rolling resistance in the bottom bracket, wheels and tires is about 15-20 watts. While this might make a difference to a pro in a TT, you or I are very unlikely to even notice that. We generate perhaps 300-400 watts full time power. The human body isn't built to notice 10% losses unless you have been riding well above your FTP for some time and have been forced to slow up. Then while you can tell that you're going slower you simply couldn't tell the source of the drag - whether bicycle or body exhaustion. Make that around 150-200 W full time power. 300-400 W full time power is Pro level, and even they can't sustain that for 5-6 hours. Really you do notice 15-20 Watt loss. Lou I notice the greaser Shimano uses seems to be lighter than the stuff I had. It was almost clear and looked clean for sure. Then wiping the grease off and cleaning the races and ball bearings everything looks nice and shiny. Repacking the bearings then it looks like a bunch of balls in mash potatoes. I notice when spinning the wheel by hand is simply comes to a rest and does not oscillate and start going the other direction. I do have the computer magnet still on spoke so not weighted even. To set the pre load not much as you just push the cone back on and the cone holding tube. Then tighten at end with 5mm allen wrench but it is a set amount already in advance. Deacon mark Maybe you need Dura Ace grease. https://tinyurl.com/y5udu5jz 105 grease is much slower. Sora grease is made out of tubular cement and should be avoided. Fun diversion. Back in the '70s, I was riding in this shop ride crypto-race, and one of the guys (who was struggling) looked over at me and said "I think I got Tubasti in my hubs." Make sure you do not have Tubasti in your hubs -- even if you put it in six zip-lock bags and lock it in a vault, it will find its way out. https://www.youtube.com/watch?v=TdUs...RetroAlexander -- Jay Beattie. Would it be better to have Vittoria Mastik or Continental rim cement instead of Tubasti? I did a Google search on tubular glue and was shocked (SHOCKED!!!!) to see so many companies making tubular glue. Vittoria, Continental, Tubasti(Velox), Vredestein, Specialized, Hutchinson, Panaracer, Schwalbe, Zefal, Challenge(Clement). Who would have thought there needs to be that many companies making tubular glue. I can count on one hand the total number of people I've met in my bicycle riding life who use tubulars. |
#18
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Things to know
On 12/7/2020 10:00 PM, wrote:
On Monday, December 7, 2020 at 12:49:52 PM UTC-6, jbeattie wrote: On Monday, December 7, 2020 at 10:08:40 AM UTC-8, wrote: On Monday, December 7, 2020 at 11:21:40 AM UTC-6, wrote: Op maandag 7 december 2020 om 18:16:25 UTC+1 schreef : On Sunday, December 6, 2020 at 3:26:11 PM UTC-8, Mark J. wrote: On 12/6/2020 2:17 PM, Mark Cleary wrote: So if you take a front road wheel and spin it by hand how long does yours spin before stopping? Today I check my front Ultegra bearings and they were fine the 10000 plus miles shows zero wear. I did pull the bearings and re-greased, cleaned them up but of course when you dump the while lithium grease back they look dirty again. Maybe should have used my marine grease but did not. In any case I spun the wheel afterward by hand the computer has it getting to 9mph and it spins about 45 seconds. I then went over to the other bike that has pretty much a front wheel with 105 hubs and simply spun that one. It manages to spin for a minute. Both smooth but I wonder if that means a damn thing? Deacon Mark I doubt the 15sec difference means much. Could be a difference in seal friction (if either of your hubs has the rubber cone-to-dust cover seals that used to be popular). Could be a minor difference in how tight you adjusted the cones. Both sound fine to me. Besides, I doubt we're very consistent with how hard we spin a wheel. What might be a finer measure of hub friction: Spin the wheel very slowly so that the wheel quits "turning over" and starts spinning/swinging back and forth as the heaviest point (usually either valve, reflector, or rim join, but not always) seeks bottom. Usually the wheel stops when the heaviest point is *near* bottom but not *at* bottom - the heavy point swings past bottom then stops, b/c friction overcomes the tiny bit that the weight is off-bottom. Spin a few times and compare the distance of the shortest "swing," and how close to bottom the heavy point is. Less friction will make the wheel continue to oscillate with shorter swings. Higher friction will stop the wheel when the swings are still kinda large. Of course a better-balanced wheel will confound all this. PS - just so long as you get *some* oscillation before the wheel stops, you're probably doing just fine. With reasonably good components the total loss to rolling resistance in the bottom bracket, wheels and tires is about 15-20 watts. While this might make a difference to a pro in a TT, you or I are very unlikely to even notice that. We generate perhaps 300-400 watts full time power. The human body isn't built to notice 10% losses unless you have been riding well above your FTP for some time and have been forced to slow up. Then while you can tell that you're going slower you simply couldn't tell the source of the drag - whether bicycle or body exhaustion. Make that around 150-200 W full time power. 300-400 W full time power is Pro level, and even they can't sustain that for 5-6 hours. Really you do notice 15-20 Watt loss. Lou I notice the greaser Shimano uses seems to be lighter than the stuff I had. It was almost clear and looked clean for sure. Then wiping the grease off and cleaning the races and ball bearings everything looks nice and shiny. Repacking the bearings then it looks like a bunch of balls in mash potatoes. I notice when spinning the wheel by hand is simply comes to a rest and does not oscillate and start going the other direction. I do have the computer magnet still on spoke so not weighted even. To set the pre load not much as you just push the cone back on and the cone holding tube. Then tighten at end with 5mm allen wrench but it is a set amount already in advance. Deacon mark Maybe you need Dura Ace grease. https://tinyurl.com/y5udu5jz 105 grease is much slower. Sora grease is made out of tubular cement and should be avoided. Fun diversion. Back in the '70s, I was riding in this shop ride crypto-race, and one of the guys (who was struggling) looked over at me and said "I think I got Tubasti in my hubs." Make sure you do not have Tubasti in your hubs -- even if you put it in six zip-lock bags and lock it in a vault, it will find its way out. https://www.youtube.com/watch?v=TdUs...RetroAlexander -- Jay Beattie. Would it be better to have Vittoria Mastik or Continental rim cement instead of Tubasti? I did a Google search on tubular glue and was shocked (SHOCKED!!!!) to see so many companies making tubular glue. Vittoria, Continental, Tubasti(Velox), Vredestein, Specialized, Hutchinson, Panaracer, Schwalbe, Zefal, Challenge(Clement). Who would have thought there needs to be that many companies making tubular glue. I can count on one hand the total number of people I've met in my bicycle riding life who use tubulars. Al the current products are OK (no more Bikit and other dreck). People like what they like but there are not dysfunctional tubular cements now. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#19
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Things to know
On Tuesday, December 8, 2020 at 7:58:13 AM UTC-6, AMuzi wrote:
On 12/7/2020 10:00 PM, wrote: On Monday, December 7, 2020 at 12:49:52 PM UTC-6, jbeattie wrote: On Monday, December 7, 2020 at 10:08:40 AM UTC-8, wrote: On Monday, December 7, 2020 at 11:21:40 AM UTC-6, wrote: Op maandag 7 december 2020 om 18:16:25 UTC+1 schreef : On Sunday, December 6, 2020 at 3:26:11 PM UTC-8, Mark J. wrote: On 12/6/2020 2:17 PM, Mark Cleary wrote: So if you take a front road wheel and spin it by hand how long does yours spin before stopping? Today I check my front Ultegra bearings and they were fine the 10000 plus miles shows zero wear. I did pull the bearings and re-greased, cleaned them up but of course when you dump the while lithium grease back they look dirty again. Maybe should have used my marine grease but did not. In any case I spun the wheel afterward by hand the computer has it getting to 9mph and it spins about 45 seconds. I then went over to the other bike that has pretty much a front wheel with 105 hubs and simply spun that one. It manages to spin for a minute. Both smooth but I wonder if that means a damn thing? Deacon Mark I doubt the 15sec difference means much. Could be a difference in seal friction (if either of your hubs has the rubber cone-to-dust cover seals that used to be popular). Could be a minor difference in how tight you adjusted the cones. Both sound fine to me. Besides, I doubt we're very consistent with how hard we spin a wheel. What might be a finer measure of hub friction: Spin the wheel very slowly so that the wheel quits "turning over" and starts spinning/swinging back and forth as the heaviest point (usually either valve, reflector, or rim join, but not always) seeks bottom. Usually the wheel stops when the heaviest point is *near* bottom but not *at* bottom - the heavy point swings past bottom then stops, b/c friction overcomes the tiny bit that the weight is off-bottom. Spin a few times and compare the distance of the shortest "swing," and how close to bottom the heavy point is. Less friction will make the wheel continue to oscillate with shorter swings. Higher friction will stop the wheel when the swings are still kinda large. Of course a better-balanced wheel will confound all this. PS - just so long as you get *some* oscillation before the wheel stops, you're probably doing just fine. With reasonably good components the total loss to rolling resistance in the bottom bracket, wheels and tires is about 15-20 watts. While this might make a difference to a pro in a TT, you or I are very unlikely to even notice that. We generate perhaps 300-400 watts full time power. The human body isn't built to notice 10% losses unless you have been riding well above your FTP for some time and have been forced to slow up. Then while you can tell that you're going slower you simply couldn't tell the source of the drag - whether bicycle or body exhaustion. Make that around 150-200 W full time power. 300-400 W full time power is Pro level, and even they can't sustain that for 5-6 hours. Really you do notice 15-20 Watt loss. Lou I notice the greaser Shimano uses seems to be lighter than the stuff I had. It was almost clear and looked clean for sure. Then wiping the grease off and cleaning the races and ball bearings everything looks nice and shiny. Repacking the bearings then it looks like a bunch of balls in mash potatoes. I notice when spinning the wheel by hand is simply comes to a rest and does not oscillate and start going the other direction. I do have the computer magnet still on spoke so not weighted even. To set the pre load not much as you just push the cone back on and the cone holding tube. Then tighten at end with 5mm allen wrench but it is a set amount already in advance. Deacon mark Maybe you need Dura Ace grease. https://tinyurl.com/y5udu5jz 105 grease is much slower. Sora grease is made out of tubular cement and should be avoided. Fun diversion. Back in the '70s, I was riding in this shop ride crypto-race, and one of the guys (who was struggling) looked over at me and said "I think I got Tubasti in my hubs." Make sure you do not have Tubasti in your hubs -- even if you put it in six zip-lock bags and lock it in a vault, it will find its way out. https://www.youtube.com/watch?v=TdUs...RetroAlexander -- Jay Beattie. Would it be better to have Vittoria Mastik or Continental rim cement instead of Tubasti? I did a Google search on tubular glue and was shocked (SHOCKED!!!!) to see so many companies making tubular glue. Vittoria, Continental, Tubasti(Velox), Vredestein, Specialized, Hutchinson, Panaracer, Schwalbe, Zefal, Challenge(Clement). Who would have thought there needs to be that many companies making tubular glue. I can count on one hand the total number of people I've met in my bicycle riding life who use tubulars. Al the current products are OK (no more Bikit and other dreck). People like what they like but there are not dysfunctional tubular cements now. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 So after my ride today a 55 miler I check the wheel and it spins again about 35-45 seconds from a hand push at 9 mph showing. I decided to pull the axel and just check things out. Nothing wrong but this time I was a bit more careful with the preload. I snugged the cone up checking the play all the way. Then when I get to where there is no play but still just easy finger tight, I could still give it some a tad more tightening. I decide that is what I must have been doing so I made the adjustment again and this time when I got the to no play in the hub but finger tight-easy, I stopped. I then put the hub all back together and still no play spins nice. I mounted the tire on the bike and gave it a spin. This time at 8-9 mph the wheel spins almost 2 minutes to stopping. So this this sound better or did I really not do anything really that much. It is interesting in the the hub still gets the pressure from the skewer being clapped tight, but spins at least twice as far. I wonder if they would let me be a mechanic somewhere in crazy land. Deacon Mark |
#20
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Things to know
Mark Cleary wrote:
On 12/6/2020 2:17 PM, Mark Cleary wrote: So if you take a front road wheel and spin it by hand how long does yours spin before stopping? Today I check my front Ultegra bearings and they were fine the 10000 plus miles shows zero wear. I did pull the bearings and re-greased, cleaned them up but of course when you dump the while lithium grease back they look dirty again. Maybe should have used my marine grease but did not. In any case I spun the wheel afterward by hand the computer has it getting to 9mph and it spins about 45 seconds. I then went over to the other bike that has pretty much a front wheel with 105 hubs and simply spun that one. It manages to spin for a minute. Both smooth but I wonder if that means a damn thing? Deacon Mark So after my ride today a 55 miler I check the wheel and it spins again about 35-45 seconds from a hand push at 9 mph showing. I decided to pull the axel and just check things out. Nothing wrong but this time I was a bit more careful with the preload. I snugged the cone up checking the play all the way. Then when I get to where there is no play but still just easy finger tight, I could still give it some a tad more tightening. I decide that is what I must have been doing so I made the adjustment again and this time when I got the to no play in the hub but finger tight-easy, I stopped. I then put the hub all back together and still no play spins nice. I mounted the tire on the bike and gave it a spin. This time at 8-9 mph the wheel spins almost 2 minutes to stopping. So this this sound better or did I really not do anything really that much. It is interesting in the the hub still gets the pressure from the skewer being clapped tight, but spins at least twice as far. I wonder if they would let me be a mechanic somewhere in crazy land. Deacon Mark 45 seconds, 35 seconds, 120 seconds ... high time you get a dynamo hub and stop worrying about unloaded Axel. The benefits? No, not the lighting. But in the event of any uncontrolled wobbling and fishing downhill dances, you will be in the comfortable position to find fault with the magnetic poles' micro-notchiness as Jay should have done -- instead of blaming his brazenly non-identical pair of summer toy tires that obviously must have been pre-damaged from all that tear gas, inner-city blazes and mostly peaceful forest arsons. |
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