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#111
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Steel is Real and Carbon is Lighter
On Sunday, June 23, 2019 at 3:05:17 PM UTC-7, Tom Kunich wrote:
On Saturday, June 22, 2019 at 8:10:16 PM UTC-7, jbeattie wrote: On Saturday, June 22, 2019 at 7:29:10 PM UTC-7, John B. wrote: On Sun, 23 Jun 2019 05:17:38 +0700, John B. wrote: On Fri, 21 Jun 2019 09:15:50 -0700 (PDT), Tom Kunich wrote: On Wednesday, June 19, 2019 at 9:49:48 AM UTC-7, duane wrote: On 19/06/2019 10:25 a.m., jbeattie wrote: On Tuesday, June 18, 2019 at 8:06:37 PM UTC-7, Frank Krygowski wrote: On 6/18/2019 1:24 PM, jbeattie wrote: On Tuesday, June 18, 2019 at 9:49:50 AM UTC-7, Frank Krygowski wrote: For ordinary riding? No, most tiny improvements make no noticeable difference. Even though we all know the near-magic power of red paint. What is a "tiny improvement"? The frame on my Emonda probably weighs less than the Columbus steel forks off my last custom racing bike. Those things were suitable for clubbing baby harp seals or home defense. Weight and stiffness do matter when climbing. If we're talking about aero bits, that's harder call -- except that dopes on aero bars riding in packs can result in a massive worsening of your riding experience. Wearing aero shoe covers may keep your feet warmer on chilly mornings, which might make you faster. It all adds up. Stiffness probably does not make a detectable difference, unless the frame is so flexible that things are scraping. Remember the discussion we had about the bike magazine's test of modern stiff CF frames vs. older, heavier steel frames? The test riders gushed about how the stiffness improved their climbing, but the math showed the speed difference was precisely what would be predicted by the weight difference. Weight matters when climbing. If getting to the top of the hill before your buddy is really, really important, a lighter bike will help by whatever the percent difference in total bike+rider weight. If a 160 pound rider changes his 20 pound bike for an 18 pound bike, he should be about 1% faster up a steep hill. Whoopee! Make that a 5lb weight difference. You need to borrow a well-fitting modern 15lb racing bike with an appropriate gear range and then do a long ride with lots of hills. It's not a subtle or imagined difference compared to a T1000 or old-school steel sport touring bike, particularly if you're trying to keep up with others. -- Jay Beattie. 5lbs? My Tarmac is probably closer to 12 lbs lighter than my cro moly Volpe. And no in reality it's not a subtle or imagined difference. And no, it's not just about weight unless everything else is exactly the same. I changed my Look pedals from CX 6 cyclocross pedals which are very easy to get into and put 206's on which were much lighter. Then since I had those 50 mm deep clinchers just sitting there I installed those The "out-the-door" weight was 21.7 lbs. for the Pinarello. I'm pulling my Basso apart to refinish it and I have another set of cheap Chinese tubeless wheels that I'll install when it get's back together. Also I think that my 44 mm bars are too wide so will reduce this to 42 mm. Chinese carbon bars as well. I think that I can keep a steel bike and have it about the same weight as the Colnago. Granted that the Colnago is not an ultra-light but my friend is touring Italy and he went to a bike factory and they advised him against buying carbon. They said that they support a racing team with these ultra-lights but that they are replaced every single race. They say that there's no way that you can get any reliability out of a piece of cloth that tears with resin on it that cracks. That last is a rather strange statement given that practically all modern recreation and work boats are made from a mixture of cloth and resin. Do you mean that my 15 year old, 40 ft sloop, that had sailed across the pacific ocean and that I sailed from Thailand to Australia and back was prone to crack? Or is this just another of your poorly thought out and wild eyed statements. As an addendum to the above I found a site that had tested a number of carbon composite samples. The average of 4 separate test samples was 982.5 MPa or 142,499psi. In comparison the ultimate tensile strength of "mild steel" (Aisi 1018) is 440 MPa or 63,816 psi. http://www.scielo.br/scielo.php?scri...92006000100016 https://www.azom.com/article.aspx?ArticleID=6115 As an aside, the carbon composite samples appeared to show no elongation before fracturing during the tensile strength testing while the mild steel specifications show a 15% elongation before failure. Also the tensile strength necessary to produce elongation of the mild steel is 370 MPa. Which illustrates a major difference between carbon composite and steel. The steel bends or elongates prior to complete failure while the carbon just breaks. -- cheers, John B. This is fascinating, but I think your first comment was correct -- Tom is either hallucinating or getting smoke blown up his a**. All my CF bikes have lifetime warranties, including an exceptionally light Emonda SLR. My brother flew CF Dreamliners and lived to retirement. The factory making disposable, one-race CF bikes is made-up by someone. -- Jay Beattie. Jay - I realize the Trek gives a lifetime warranty on the frameset. And my friend has exercised that three times. Another friend had a Lynskey titanium frame and I warned him to watch for cracks since the material is EXTREMELY sensitive to oxidation in the welding process. He laughed in my face and the very following week I pointed out a crack around the upper headset. Yup, things break. And with your history of breaking CF forks, I might warn you away from anything CF, even a bottle opener. https://images.bonanzastatic.com/afu...74/s-l1600.jpg If I broke a pair of forks, I might be leading the Grant Peterson anti-CF parade with my wool shako and steel baton. However, after 25 years, I've yet to break a set. -- Jay Beattie. |
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#112
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Steel is Real and Carbon is Lighter
On Sun, 23 Jun 2019 10:53:31 -0700, sms
wrote: On 6/23/2019 8:42 AM, jbeattie wrote: snip Yes, like this anecdote. And for a lawsuit counter-anecdote, I've been representing Trek and Specialized in Oregon for over 20 years. It's like being the mythical Maytag repairman. There is not an epidemic of old CF frame failures resulting in lawsuits. Be careful there..."Among dishwasher owners, 13 percent of Maytag purchases required repairs, more than Bosch (7 percent), Whirlpool (8 percent), Miele (9 percent) and Kenmore (11 percent). Among refrigerators, Maytag ranked third, behind Kenmore and Samsung while among washing machines, it was tied for fourth with Whirlpool, behind LG, Samsung, and Kenmore." Your comments seem rather, well "strange", as I researched your figures and I find that based on 34,687 service calls during 2018 YALE Appliances and Lighting stated that in their experience: Maytag - Shipped 29, service required 3, service ratio 10.3 Bosch - Shipped 2735, service required 303, service ratio 11.08 Whirlpool - Shipped 1030, service required 44, service ratio 4.27 Miele - Shipped 1078, service required 155, service ratio 14.38 https://blog.yaleappliance.com/most-...shwashers-2019 In short your figures seem to have no basis in reality.. (as do many of your other "facts") The Maytag repairman isn't so lonely anymore. https://www.nytimes.com/2014/01/09/business/media/maytag-repairmans-new-job-keeps-him-busy.html. It is true, though, that CF fails differently than steel and some internal damage is not apparent. When my Supersix was trashed in a roof rack incident, I had it inspected by Ruckus. https://ruckuscomp.com/inspection. They confirmed that it was indeed trashed, and in some areas I had not expected. So I got a new bike. I would have spent a similar amount repairing steel and getting a paint job -- particularly if I went with wet paint. Gads, nice paint is incredibly expensive these days. The moral of the story is that if you're worried about internal frame damage, have the frame inspected. Someone buying a used CF frame is unlikely to be the kind of person that will spent several hundred dollars on a proper inspection. You can get failures in any product, and high volume products have ascertainable defect rates, generally very low with reputable manufacturers. The good news is that most bicycle failures result in warranty claims and not personal injuries. The exception is forks. Reputable manufacturers have spent lots of time and money on getting forks right -- and they police their contractors. CF forks are the standard now, even on steel and aluminum bikes. And note that steel forks are not without their problems. https://www.cpsc.gov/Recalls/2013/Sa...-Bicycle-Forks But if CF forks are too scary, get steel. They're still available. I've been riding on CF forks since about '92 when I got first generation Kestrel forks, and I haven't looked back. Yes, fork failures have been the most common and most likely to cause injury. For a while Rivendell was offering a replacement program, offering their steel forks at a discount when exchanged for a CF fork. http://web.archive.org/web/20100801102119/http://www.rivbike.com/products/show/carbonoms-fork/50-718 "Our offer: The fork sells for $200, and we won't have them 'till August 1. Call 800-345-3918 or email to pre-order. Or, if you send us your carbon fork (write your name on the steerer tube, address below, along with your contact info), we'll sell you its replacement for $115. We will permanently remove your fork from circulation. That is the point, after all. If you sell it on eBay, the problem is still out there." -- cheers, John B. |
#114
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Steel is Real and Carbon is Lighter
On Sun, 23 Jun 2019 22:17:25 -0000 (UTC), Duane
wrote: wrote: On Sunday, June 23, 2019 at 10:35:04 AM UTC+2, Tosspot wrote: On 23/06/2019 03.29, John B. wrote: On Sun, 23 Jun 2019 05:17:38 +0700, John B. wrote: On Fri, 21 Jun 2019 09:15:50 -0700 (PDT), Tom Kunich wrote: On Wednesday, June 19, 2019 at 9:49:48 AM UTC-7, duane wrote: On 19/06/2019 10:25 a.m., jbeattie wrote: On Tuesday, June 18, 2019 at 8:06:37 PM UTC-7, Frank Krygowski wrote: On 6/18/2019 1:24 PM, jbeattie wrote: On Tuesday, June 18, 2019 at 9:49:50 AM UTC-7, Frank Krygowski wrote: For ordinary riding? No, most tiny improvements make no noticeable difference. Even though we all know the near-magic power of red paint. What is a "tiny improvement"? The frame on my Emonda probably weighs less than the Columbus steel forks off my last custom racing bike. Those things were suitable for clubbing baby harp seals or home defense. Weight and stiffness do matter when climbing. If we're talking about aero bits, that's harder call -- except that dopes on aero bars riding in packs can result in a massive worsening of your riding experience. Wearing aero shoe covers may keep your feet warmer on chilly mornings, which might make you faster. It all adds up. Stiffness probably does not make a detectable difference, unless the frame is so flexible that things are scraping. Remember the discussion we had about the bike magazine's test of modern stiff CF frames vs. older, heavier steel frames? The test riders gushed about how the stiffness improved their climbing, but the math showed the speed difference was precisely what would be predicted by the weight difference. Weight matters when climbing. If getting to the top of the hill before your buddy is really, really important, a lighter bike will help by whatever the percent difference in total bike+rider weight. If a 160 pound rider changes his 20 pound bike for an 18 pound bike, he should be about 1% faster up a steep hill. Whoopee! Make that a 5lb weight difference. You need to borrow a well-fitting modern 15lb racing bike with an appropriate gear range and then do a long ride with lots of hills. It's not a subtle or imagined difference compared to a T1000 or old-school steel sport touring bike, particularly if you're trying to keep up with others. -- Jay Beattie. 5lbs? My Tarmac is probably closer to 12 lbs lighter than my cro moly Volpe. And no in reality it's not a subtle or imagined difference. And no, it's not just about weight unless everything else is exactly the same. I changed my Look pedals from CX 6 cyclocross pedals which are very easy to get into and put 206's on which were much lighter. Then since I had those 50 mm deep clinchers just sitting there I installed those The "out-the-door" weight was 21.7 lbs. for the Pinarello. I'm pulling my Basso apart to refinish it and I have another set of cheap Chinese tubeless wheels that I'll install when it get's back together. Also I think that my 44 mm bars are too wide so will reduce this to 42 mm. Chinese carbon bars as well. I think that I can keep a steel bike and have it about the same weight as the Colnago. Granted that the Colnago is not an ultra-light but my friend is touring Italy and he went to a bike factory and they advised him against buying carbon. They said that they support a racing team with these ultra-lights but that they are replaced every single race. They say that there's no way that you can get any reliability out of a piece of cloth that tears with resin on it that cracks. That last is a rather strange statement given that practically all modern recreation and work boats are made from a mixture of cloth and resin. Do you mean that my 15 year old, 40 ft sloop, that had sailed across the pacific ocean and that I sailed from Thailand to Australia and back was prone to crack? Or is this just another of your poorly thought out and wild eyed statements. As an addendum to the above I found a site that had tested a number of carbon composite samples. The average of 4 separate test samples was 982.5 MPa or 142,499psi. In comparison the ultimate tensile strength of "mild steel" (Aisi 1018) is 440 MPa or 63,816 psi. http://www.scielo.br/scielo.php?scri...92006000100016 https://www.azom.com/article.aspx?ArticleID=6115 As an aside, the carbon composite samples appeared to show no elongation before fracturing during the tensile strength testing while the mild steel specifications show a 15% elongation before failure. Also the tensile strength necessary to produce elongation of the mild steel is 370 MPa. Which illustrates a major difference between carbon composite and steel. The steel bends or elongates prior to complete failure while the carbon just breaks. Which is what makes CF frames incredibly rigid. They are fun to ride because you feel that every erg on the pedal converts to KE without loss. I've never owned one so can't comment on the 'rough ride' criticism, but I could believe it. When do the old farts learn to understand that the properties of CF depends on the direction. Today CF frames are one of most comfortable frames. Lou I mentioned that once and got blasted by a bunch of people here. I doubt any had ridden a decent CF road bike. So I stopped paying attention to their posts. Although I have to admit that the age of old farts seems to be a moving target. Well, Yes! After all , as the song would have it "another day older (and deeper in debt)". -- cheers, John B. |
#115
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Steel is Real and Carbon is Lighter
On Sun, 23 Jun 2019 09:29:05 +0700, John B.
wrote: The steel bends or elongates prior to complete failure while the carbon just breaks. Veering sharply off-topic, that reminds me of the plastic clothespin that snapped and cut my hand. A wooden clothespin will also be destroyed by exposure to sunlight, but when it fails, it just sighs and gives up. I haven't seen plastic clothespins in the stores recently. I've got a mouthful of plastic that got stronger when exposed to ultraviolet. I don't expect to test its resistance to sunlight -- I'm not *that* happy a cyclist! -- Joy Beeson joy beeson at comcast dot net http://wlweather.net/PAGEJOY/ |
#116
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Steel is Real and Carbon is Lighter
On Sun, 23 Jun 2019 22:47:40 -0400, Joy Beeson
wrote: On Sun, 23 Jun 2019 09:29:05 +0700, John B. wrote: The steel bends or elongates prior to complete failure while the carbon just breaks. Veering sharply off-topic, that reminds me of the plastic clothespin that snapped and cut my hand. A wooden clothespin will also be destroyed by exposure to sunlight, but when it fails, it just sighs and gives up. I haven't seen plastic clothespins in the stores recently. Here, I don't believe that I've ever seen a wooden clothespin. Everything seems to be plastic these days. I just asked my wife about wooden clothespins and she said that she remembers them from when she was a little girl, 5 - 10 years old. I've got a mouthful of plastic that got stronger when exposed to ultraviolet. I don't expect to test its resistance to sunlight -- I'm not *that* happy a cyclist! -- cheers, John B. |
#117
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Steel is Real and Carbon is Lighter
On 6/23/2019 7:47 PM, Joy Beeson wrote:
On Sun, 23 Jun 2019 09:29:05 +0700, John B. wrote: The steel bends or elongates prior to complete failure while the carbon just breaks. Veering sharply off-topic, that reminds me of the plastic clothespin that snapped and cut my hand. A wooden clothespin will also be destroyed by exposure to sunlight, but when it fails, it just sighs and gives up. I haven't seen plastic clothespins in the stores recently. Ditto. Wooden clothespins are all that are available here. Ever since I built my nuclear fusion powered clothes dryer (a clothesline) we've only ever had wooden clothespins. I seem to remember plastic clothespins but it's been decades since I've seen them, but they can still be purchased online https://www.aliexpress.com/item/32962556941.html. |
#118
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Steel is Real and Carbon is Lighter
On Monday, June 24, 2019 at 1:01:32 AM UTC+2, jbeattie wrote:
The assurance of a credible seller that a CF frame has not been crashed is probably adequate. I'm sure Lou was honest about his crash history, if any. There are certain simple rules you have to follow when buying, using and for decent people also selling a high end CF bike. The rules are simple and you can look them up. I used that bike for 8 years with an average milage of 3500 km/yr. I wiped out in a corner once at low speed and my body (elbow and hip) took the hit. Only one of the limit screws of the rear derailleur was scratched a bit. Do you think I would sell a high end CF bike that took a severe hit to a friend or a stranger? I mentioned it before, if you want to throw a bike in the back of a pick-up truck, stay away from 800 gr CF frames. Lou |
#119
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Steel is Real and Carbon is Lighter
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#120
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Steel is Real and Carbon is Lighter
On 6/22/2019 4:24 PM, Frank Krygowski wrote:
On 6/22/2019 3:16 PM, Tom Kunich wrote: On Friday, June 21, 2019 at 3:55:05 PM UTC-7, jbeattie wrote: Today's ride: https://localfreshies.com/wp-content..._2014_V1.jpgÂ* Mt. Bachelor.Â* The winds were howling at the top, and I almost had a Froome moment coming down -- and I was on modest C35s and not super deep-dish sails. -- Jay Beattie. This was why I wanted to make the point that these cheapo deep aero clinchers do not run off on me - they are no more sensitive to side gusts than some of those old Campy Proton wheels which were flat sections. I assumption is that it is the spoke tension but it may be the directional stability of the Victoria Corsa G+ tires. I've used these clinchers on the Aero frame of the Colnago and the very non-aero frame of the Pinarello Stelvio and they seem to react that same way. OK, my guess on crosswind stability and aero wheels: With an old fashioned, unstreamlined sort of box section rim, the cross section of the forward part of wheel is a simple bluff body. Air hits it and goes turbulent no matter what the angle of attack - that is, no matter if there's zero wind, or if there's a sidewind causing the air to come at the rim at an angle. So the front and rear portions of the wheel get roughly the same amount and direction of force. The more a tire+rim looks like a teardrop or airfoil, the less that is true. The airfoil shape will certainly give less drag if it's pointed directly into the relative wind (that is, if there is no sidewind). But for many values of sidewind, the relative wind is at an angle of attack that causes a significant sideways "lifting" force on the front part of the wheel. [Rather, it would be a lifting force if the airfoil were horizontal, as an airplane wing.] On the bike, this is a lateral force that tries to steer the front of the wheel away from the wind. The backside of the wheel sees the same angle of attack, but its airfoil is oriented backward so it's much less efficient at generating side force. The sideways force there is much less, so the front and rear side forces are much less balanced than for a normal wheel. The more streamlined the wheel+tire, the better this works. So I'm not surprised aero wheels would be sensitive to side winds. I don't think loose spokes have anything significant to do with this, assuming the spokes don't go dead slack. In fact, I don't think tighter spokes increase the rigidity of the wheel. The stiffness (or modulus of elasticity) of a spoke with 50 kgf tension is the same as a spoke with 100 kgf tension. They're both within the elastic range of the material, where strain is proportional to stress, so the same force will cause the same deflection. That's what I think. We can discuss. Yesterday's club ride was at a pretty relaxed pace, but one guy had brand new and extremely deep section aero rims. Sorry, I didn't catch the brand. But as we passed him, I asked "How are those rims in crosswinds?" He said "Terrible. They're actually scary, really scary." -- - Frank Krygowski |
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