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#72
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Conbtinental has come out with a GP5000S and a GP5000TL
On Wednesday, February 20, 2019 at 4:09:05 PM UTC-8, John B. Slocomb wrote:
On Wed, 20 Feb 2019 10:21:21 -0800 (PST), wrote: On Wednesday, February 20, 2019 at 9:56:55 AM UTC-8, duane wrote: On 20/02/2019 10:50 a.m., Joerg wrote: On 2019-02-18 08:39, Duane wrote: On 18/02/2019 10:16 a.m., Joerg wrote: On 2019-02-18 05:35, Duane wrote: On 17/02/2019 10:57 a.m., Joerg wrote: On 2019-02-11 15:32, wrote: On Sunday, February 10, 2019 at 4:54:06 PM UTC-8, Duane wrote: wrote: On Sunday, February 10, 2019 at 3:52:27 PM UTC+1, Duane wrote: wrote: On Saturday, February 9, 2019 at 7:56:22 PM UTC+1, Joerg wrote: On 2019-02-09 09:52, wrote: I learned pretty soon that paying more than $20 for a road bike tire is a waste of money. In fact, they can be worse than expensive tires. Similar for MTB tires. That depends on your riding conditions and requirements. I ride on good roads on my road bikes and get 4500 km out of a Continental 4000S(2) rear tire and expect the same from the 5000 so price is not that important. Lou I get about the same mileage and very few flats.Â* I think I’ve had one flat in the last 10,000km and that was a tube giving out when I hit a pothole hard.Â* I ride on roads but I can’t say they’re always good roads. Maybe Joerg is riding his road bike on single track carrying 4 gallons of water or something... 1-1/2 gallons max, on hot summer days. This is required on some rides unless you carry chlorine tablets, can stomach that taste _and_ suppress any thoughts about what you've seen in the river during kayaking further upstream. So you're riding a road bike on single track carrying 1-1/2 gallons of water.Â* Maybe you have the wrong bike for that. No, I use a 29" FS MTB for that. What I am saying is that the problem with tires is basically the same whether road bike or MTB. Expensive tires are designed towards light weight and performance. Then, their sidewalls fail. My point is that you seem to have different results from anyone I know with respect to tires.Â* I don't know anyone doing any serious mileage on a road bike that thinks cheaper tires are better. I have met lots of road bike riders who have realized that expensive tires just aren't worth it unless you plan to participate in the Amgen Tour, every millisecond counts and a team car is there at your beck and call. Saying that the additional cost is not worth the return for your specific use case is different than saying that cheaper tires are better than expensive tires. They _are_ better. To be "better" isn't necessarily something that has a better cost/performance ratio but somthing that doesn't go KAPOOF during ride. I didn't have flats in years, neither on the MTB nor the road bike. Mission accomplished, I'd say, and it was accomplished by switching to Asian tires. As I said this is different for competitive riders who get a new bike from the team car the second a tire is flat. I do not have a team car, do not belong to that group and never will. Well we do have one guy that buys chinese knock off tires online.Â* He's had so many split tires that we are contemplating a GoFundMe page for him so we don't have to keep stopping to put boots in his tires.... Very different here. The rolling surface does wear down within 2000mi which is slighlty lower than the 2500mi I could milk out of a Gatorskin. However, I get 2000mi out of every tire while I only got around 1000mi out of the Gatorskins where the sidewalls blew. Are you talking about single track now or are you saying your roads wear tires down more than say Quebec roads?Â* Hard to keep track.Â* And do the Gatorskin tires just blow sidewalls or are you running into ruts or something? Again, my statement goes for _both_ road and offroad. I do not know Quebec roads but ours in California have a lot of debris and are often in very poor condition. Pieces of asphalt broken out and laying on top and such. The result of inept government. https://www.google.ca/search?q=quebe...CAAQCA#imgrc=_ Here it's partially the government, partially the +/-40 C temperature swings and partially the mob supplying the asphalt. We seem to get by without your tire issues for the most part. I'm getting ~5000km from my Conti 4000s and rarely get flats. I try to avoid potholes but I have hit one that caused my tube to split but I haven't cut a sidewall yet. This happens when you ride in a tight group and the guy in front of you moves to avoid the hole at the last second without warning. But you say you keep yards between you and any other riders so it's hard to understand your issues. Whatever. Use what works for you. On trails the tire torture is of more natural causes, decomposed granite and sharp rocks, some embedded and some rolling. Then both on roads and trails there are these which go into runnig surfaces and sometimes side walls: https://en.wikipedia.org/wiki/Goat%2...idum_seeds.jpg If you're talking about trail riding then why do you say road bike? I don't ride my Tarmac on single track unless I can't avoid it which is never. A bike shop owner told me that they aren't native but came in from places like Arizona just a few years ago. Anyhow, we've got to deal with all that. All this assumes a tire liner so I can ride tires down to their "last mile". In goat's head thorn country wheer I live a liner is the prudent to do anyhow. Not sure what you mean by a tire liner. ... This: https://www.amazon.com/Mr-Tuffy-Bicy.../dp/B078FHD1ZH Worth every penny. Â*... It's not like they are optional as far as I know. They are optional. Some tires (supposedly) have something similar built in but my experience is that it fails as soon as the thorn or whatever hits far enough off-center. In addition I have thick thron-resistant tubes in the MTB and road bike tires. For the MTB the tire liner is then sleeved by a reguar good quality tube with the valve stem removed and slit. That combination seems to be indestructable. Which was my goal. My experience with cheap tires was absolutely horrible. They flatted if you look sideways at them and they wore out so rapidly that they cost more than using more expensive longer wearing tires. I'm sort of wondering just how far over the edge that Joerg is willing to take his tires before replacing them. I very rarely get more than 2,500 miles on the very longest wearing tires. I believe that he is approximately my size and yet he gets almost twice that distance if I understand him correctly. Or we can go with Frank's previous claim that the graphene layer in my Vittoria tires doesn't protect anything because a layer only 8 molecules thick couldn't possibly protect anything. http://www.ukm.my/jsm/pdf_files/SM-P...in%20Chong.pdf This was a test in medical gloves that have to have several times the stretch of tires and yet even the very small pieces of graphene yielded an 11% increase in puncture resistance. Actually, if you actually read the study it showed that a thickness of 0.0177" provided the greatest resistance. Please note that this is substantially thicker then the 8 molecules you mention above. And, of course, Frank denies that he ever said such a thing so is this yet another example of "The Sky is Falling! The Sky is Falling!"? -- Cheers, John B. These gloves were bult not with a sheet in the gloves but with particles. That means that in order to cover as much space as possible without harming the required flexibility they placed the largest pieces of graphene in there possible. Do you think that needle pricks in hospital conditions is something not to worry about? If Frank didn't make that comment about graphene not stopping anything because it was only a molecule thick than you or one of your other argument makers did. |
#73
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Conbtinental has come out with a GP5000S and a GP5000TL
On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote:
On 2/20/2019 6:30 PM, jbeattie wrote: Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire. It might be interesting to try some simple coast-down tests. If you have any hills with pretty consistent slope but not too steep, you could run them at (say) 75 psi and coast down noting your time between two landmarks. Then ride back up, inflate to 90 and repeat the trial. If done on a day without wind, you'd probably get a realistic estimate of how rolling resistance varies with those two pressures. You say you don't use cyclometers. But those with cyclometers mounted might just use the speeds indicated to tell the difference. -- - Frank Krygowski Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared. |
#74
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Conbtinental has come out with a GP5000S and a GP5000TL
On 2019-02-21 09:38, wrote:
On Wednesday, February 20, 2019 at 12:44:59 PM UTC-8, Joerg wrote: On 2019-02-20 10:21, wrote: [...] Or we can go with Frank's previous claim that the graphene layer in my Vittoria tires doesn't protect anything because a layer only 8 molecules thick couldn't possibly protect anything. http://www.ukm.my/jsm/pdf_files/SM-P...in%20Chong.pdf This was a test in medical gloves that have to have several times the stretch of tires and yet even the very small pieces of graphene yielded an 11% increase in puncture resistance. The Vittoria tires have overlapping sheets of the material making it very puncture resistant. Now these most certainly aren't in the realm of Joerg's "cheap tires" but they are made in Thailand. Including shipping I paid $12/ea for the Vittoria Zafiros. That qualifies as low cost in my book. Jay wrote they don't last but I get well north of 1500mi out of them and I am not babying my road bike. It rolls over some nasty stuff. So if there was another sale and I needed to restock on tires I'd buy those again. -- Regards, Joerg http://www.analogconsultants.com/ When I tried the Zafiros I started getting flats within 500 miles. That's why I was very hesitant to try the higher priced Vittorias. But the G+ tires seem really great so far. This is one of the reasons why I use tire liners. No flats ever with the Zafiros and I wear them down to bare minimums. Or past that. They have no TWI so one never really knows when they are finished. When you never get flats you can't feel the remaining thickness because the tire never comes off until it's worn. -- Regards, Joerg http://www.analogconsultants.com/ |
#75
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Conbtinental has come out with a GP5000S and a GP5000TL
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#76
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Conbtinental has come out with a GP5000S and a GP5000TL
On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 12:52 PM, wrote: On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote: On 2/20/2019 6:30 PM, jbeattie wrote: Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire. It might be interesting to try some simple coast-down tests. If you have any hills with pretty consistent slope but not too steep, you could run them at (say) 75 psi and coast down noting your time between two landmarks. Then ride back up, inflate to 90 and repeat the trial. If done on a day without wind, you'd probably get a realistic estimate of how rolling resistance varies with those two pressures. You say you don't use cyclometers. But those with cyclometers mounted might just use the speeds indicated to tell the difference. -- - Frank Krygowski Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared. When you say the road "would flatten out" do you mean it was horizontal, instead of downhill? Or do you mean the bumps went away and it remained downhill? -- - Frank Krygowski It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road. |
#77
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Conbtinental has come out with a GP5000S and a GP5000TL
On 2/21/2019 4:27 PM, wrote:
On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote: On 2/21/2019 12:52 PM, wrote: On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote: On 2/20/2019 6:30 PM, jbeattie wrote: Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire. It might be interesting to try some simple coast-down tests. If you have any hills with pretty consistent slope but not too steep, you could run them at (say) 75 psi and coast down noting your time between two landmarks. Then ride back up, inflate to 90 and repeat the trial. If done on a day without wind, you'd probably get a realistic estimate of how rolling resistance varies with those two pressures. You say you don't use cyclometers. But those with cyclometers mounted might just use the speeds indicated to tell the difference. -- - Frank Krygowski Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared. When you say the road "would flatten out" do you mean it was horizontal, instead of downhill? Or do you mean the bumps went away and it remained downhill? -- - Frank Krygowski It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road. OK, if you were coasting and you had no tailwind that exceeded your speed, you had nobody pushing you forward (which I've done for people many times), and you had no rope towing you or some other weird situation... And your bike actually accelerated when the road was horizontal? Yes, that's impossible. Sorry, Tom, this is basic physics. (And I had to include the rope tow because that was Jute's "deus ex machina" on his first weird braggart tale here.) Your story does, however, indicate the power of suggestion and how it can mess with our perceptions. -- - Frank Krygowski |
#78
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Conbtinental has come out with a GP5000S and a GP5000TL
On Thursday, February 21, 2019 at 1:46:38 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 4:27 PM, wrote: On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote: On 2/21/2019 12:52 PM, wrote: On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote: On 2/20/2019 6:30 PM, jbeattie wrote: Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire. It might be interesting to try some simple coast-down tests. If you have any hills with pretty consistent slope but not too steep, you could run them at (say) 75 psi and coast down noting your time between two landmarks. Then ride back up, inflate to 90 and repeat the trial. If done on a day without wind, you'd probably get a realistic estimate of how rolling resistance varies with those two pressures. You say you don't use cyclometers. But those with cyclometers mounted might just use the speeds indicated to tell the difference. -- - Frank Krygowski Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared. When you say the road "would flatten out" do you mean it was horizontal, instead of downhill? Or do you mean the bumps went away and it remained downhill? -- - Frank Krygowski It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road. OK, if you were coasting and you had no tailwind that exceeded your speed, you had nobody pushing you forward (which I've done for people many times), and you had no rope towing you or some other weird situation.... And your bike actually accelerated when the road was horizontal? Yes, that's impossible. Sorry, Tom, this is basic physics. (And I had to include the rope tow because that was Jute's "deus ex machina" on his first weird braggart tale here.) Your story does, however, indicate the power of suggestion and how it can mess with our perceptions. -- - Frank Krygowski Frank, if this is against physics why haven't you actually explained this to us? To my way of thinking if E = 1/2M*V^2 and you reduce the rolling resistance you coast for a longer distance to expend the energy. But that isn't what happened. As I said - when I hit the smooth pavement the bike increased its speed. This was not a single case but multiple experiments and as the smooth pavement degraded over the summer and grew rougher the increasing speed disappeared at least to the level where it wasn't detectable. |
#79
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Conbtinental has come out with a GP5000S and a GP5000TL
On Friday, February 22, 2019 at 6:31:09 PM UTC+1, wrote:
On Thursday, February 21, 2019 at 1:46:38 PM UTC-8, Frank Krygowski wrote: On 2/21/2019 4:27 PM, wrote: On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote: On 2/21/2019 12:52 PM, wrote: On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote: On 2/20/2019 6:30 PM, jbeattie wrote: Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire. It might be interesting to try some simple coast-down tests. If you have any hills with pretty consistent slope but not too steep, you could run them at (say) 75 psi and coast down noting your time between two landmarks. Then ride back up, inflate to 90 and repeat the trial. If done on a day without wind, you'd probably get a realistic estimate of how rolling resistance varies with those two pressures. You say you don't use cyclometers. But those with cyclometers mounted might just use the speeds indicated to tell the difference. -- - Frank Krygowski Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared. When you say the road "would flatten out" do you mean it was horizontal, instead of downhill? Or do you mean the bumps went away and it remained downhill? -- - Frank Krygowski It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road. OK, if you were coasting and you had no tailwind that exceeded your speed, you had nobody pushing you forward (which I've done for people many times), and you had no rope towing you or some other weird situation... And your bike actually accelerated when the road was horizontal? Yes, that's impossible. Sorry, Tom, this is basic physics. (And I had to include the rope tow because that was Jute's "deus ex machina" on his first weird braggart tale here.) Your story does, however, indicate the power of suggestion and how it can mess with our perceptions. -- - Frank Krygowski Frank, if this is against physics why haven't you actually explained this to us? To my way of thinking if E = 1/2M*V^2 and you reduce the rolling resistance you coast for a longer distance to expend the energy. But that isn't what happened. As I said - when I hit the smooth pavement the bike increased its speed. This was not a single case but multiple experiments and as the smooth pavement degraded over the summer and grew rougher the increasing speed disappeared at least to the level where it wasn't detectable. I think what Frank tries to say is that to be able to accelerate there must be a driving force, one of Newtons laws. If you are coasting on flat terrain without a tailwind there is no driving force. Lou |
#80
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Conbtinental has come out with a GP5000S and a GP5000TL
On 2/22/2019 1:39 PM, wrote:
On Friday, February 22, 2019 at 6:31:09 PM UTC+1, wrote: On Thursday, February 21, 2019 at 1:46:38 PM UTC-8, Frank Krygowski wrote: On 2/21/2019 4:27 PM, wrote: On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote: On 2/21/2019 12:52 PM, wrote: On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote: On 2/20/2019 6:30 PM, jbeattie wrote: Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire. It might be interesting to try some simple coast-down tests. If you have any hills with pretty consistent slope but not too steep, you could run them at (say) 75 psi and coast down noting your time between two landmarks. Then ride back up, inflate to 90 and repeat the trial. If done on a day without wind, you'd probably get a realistic estimate of how rolling resistance varies with those two pressures. You say you don't use cyclometers. But those with cyclometers mounted might just use the speeds indicated to tell the difference. -- - Frank Krygowski Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared. When you say the road "would flatten out" do you mean it was horizontal, instead of downhill? Or do you mean the bumps went away and it remained downhill? -- - Frank Krygowski It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road. OK, if you were coasting and you had no tailwind that exceeded your speed, you had nobody pushing you forward (which I've done for people many times), and you had no rope towing you or some other weird situation... And your bike actually accelerated when the road was horizontal? Yes, that's impossible. Sorry, Tom, this is basic physics. (And I had to include the rope tow because that was Jute's "deus ex machina" on his first weird braggart tale here.) Your story does, however, indicate the power of suggestion and how it can mess with our perceptions. -- - Frank Krygowski Frank, if this is against physics why haven't you actually explained this to us? To my way of thinking if E = 1/2M*V^2 and you reduce the rolling resistance you coast for a longer distance to expend the energy. But that isn't what happened. As I said - when I hit the smooth pavement the bike increased its speed. This was not a single case but multiple experiments and as the smooth pavement degraded over the summer and grew rougher the increasing speed disappeared at least to the level where it wasn't detectable. I think what Frank tries to say is that to be able to accelerate there must be a driving force, one of Newtons laws. If you are coasting on flat terrain without a tailwind there is no driving force. Exactly. In fact, there are retarding forces, those being air resistance and rolling resistance, at a minimum. And as to Tom's question, why haven't I explained it? I guess I foolishly persist in believing that some things are obvious to educated people. -- - Frank Krygowski |
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