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#21
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Schwalbe Marathon Plus Failure
Pete Biggs wrote:
Roger Merriman wrote: i can don't tend to slow for potholes/speedbumps etc, quite happy to use the odd bridleway if it connects, ie i'm fairly hard on the bike. it was intended as a simple knock about town, but it gets use a lot more heavly than that. Perhaps the sidewalls are coming into contact with some of the rough stuff you ride. That can happen. Otherwise, I reckon the air should protect them from damage. i think it's just the flexing the tire takes rather than being grazed. even at 80psi there will be a fair amount of give, i had some simular sized landcruisers which pinchflatted all the time, as the sidewalls just didn't have the support. Again, air pressure should prevent pinch-flats (there needs to be some give, but not too much). I don't know of a bicycle tyre that has enough enforcement to prevent pinch-flats when the pressure is low. (Tubeless tyres are used by mountain bikers using very low pressure). ~PB even at high pressures, hit something, big enought or fast enought and if the the sidewalls aren't robust enought the tire will pinch flat. roger -- www.rogermerriman.com |
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#22
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Schwalbe Marathon Plus Failure
Roger Merriman wrote:
Pete Biggs wrote: Roger Merriman wrote: i can don't tend to slow for potholes/speedbumps etc, quite happy to use the odd bridleway if it connects, ie i'm fairly hard on the bike. it was intended as a simple knock about town, but it gets use a lot more heavly than that. Perhaps the sidewalls are coming into contact with some of the rough stuff you ride. That can happen. Otherwise, I reckon the air should protect them from damage. i think it's just the flexing the tire takes rather than being grazed. Maybe, though I'm not sure the extra flexing caused by bumps in the ground is ever in the same league as the flexing an under-inflated tyre gets even on a perfectly smooth road - when there is excessive flexing continually as the wheel turns with weight on it. even at 80psi there will be a fair amount of give, i had some simular sized landcruisers which pinchflatted all the time, as the sidewalls just didn't have the support. Again, air pressure should prevent pinch-flats (there needs to be some give, but not too much). I don't know of a bicycle tyre that has enough enforcement to prevent pinch-flats when the pressure is low. (Tubeless tyres are used by mountain bikers using very low pressure). even at high pressures, hit something, big enought or fast enought and if the the sidewalls aren't robust enought the tire will pinch flat. A pinch flat happens when the tyre completely compresses. You can prevent that ever happening by using very high pressure. No pneumatic bicycle tyre I've ever seen or heard of will have robust enough sidewalls to prevent pinch flats. It's air pressure alone that does that job. I've used tyres with delicate sidewalls that have survived potholes that were bad enough to chuck me off the bike. The tyres remained undamaged and inflated. ~PB |
#23
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Schwalbe Marathon Plus Failure
Pete Biggs wrote:
Roger Merriman wrote: Pete Biggs wrote: Roger Merriman wrote: i can don't tend to slow for potholes/speedbumps etc, quite happy to use the odd bridleway if it connects, ie i'm fairly hard on the bike. it was intended as a simple knock about town, but it gets use a lot more heavly than that. Perhaps the sidewalls are coming into contact with some of the rough stuff you ride. That can happen. Otherwise, I reckon the air should protect them from damage. i think it's just the flexing the tire takes rather than being grazed. Maybe, though I'm not sure the extra flexing caused by bumps in the ground is ever in the same league as the flexing an under-inflated tyre gets even on a perfectly smooth road - when there is excessive flexing continually as the wheel turns with weight on it. no but the tire is year old so not as if it's failing that quickly, considering the weight and loads the rear takes it's not that susprising. even at 80psi there will be a fair amount of give, i had some simular sized landcruisers which pinchflatted all the time, as the sidewalls just didn't have the support. Again, air pressure should prevent pinch-flats (there needs to be some give, but not too much). I don't know of a bicycle tyre that has enough enforcement to prevent pinch-flats when the pressure is low. (Tubeless tyres are used by mountain bikers using very low pressure). even at high pressures, hit something, big enought or fast enought and if the the sidewalls aren't robust enought the tire will pinch flat. A pinch flat happens when the tyre completely compresses. You can prevent that ever happening by using very high pressure. No pneumatic bicycle tyre I've ever seen or heard of will have robust enough sidewalls to prevent pinch flats. It's air pressure alone that does that job. er no, side walls are the real battle ground between duriblity and weight, no they can not do it on there own, but the stiffness of the side wall has a real differnce, on the work horse, one could pinch flat, the rear with the land cruisers where as you'd have a job with the marthon pluses, same sorts of pressures 80 psi or higher, and big wide road tires, but the marthon's have much more substantal sidewalls. I've used tyres with delicate sidewalls that have survived potholes that were bad enough to chuck me off the bike. The tyres remained undamaged and inflated. you don't need a big pot hole etc just something edged to pinch the tire. ~PB roger -- www.rogermerriman.com |
#24
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Schwalbe Marathon Plus Failure
Roger Merriman wrote:
A pinch flat happens when the tyre completely compresses. You can prevent that ever happening by using very high pressure. No pneumatic bicycle tyre I've ever seen or heard of will have robust enough sidewalls to prevent pinch flats. It's air pressure alone that does that job. er no, side walls are the real battle ground between duriblity and weight, I'm not taking about the durability of the sidewall here, only what difference it makes to pinching while it is still intact. no they can not do it on there own, but the stiffness of the side wall has a real differnce, I would not use lower pressure because I had more sustantial sidewalls. I don't believe sidewalls help enough in that way. The resistance to pinching that the pressurised air provides is very many times higher than anything the tyre material is doing. on the work horse, one could pinch flat, the rear with the land cruisers where as you'd have a job with the marthon pluses, same sorts of pressures 80 psi or higher, and big wide road tires, but the marthon's have much more substantal sidewalls. I've used tyres with delicate sidewalls that have survived potholes that were bad enough to chuck me off the bike. The tyres remained undamaged and inflated. you don't need a big pot hole etc just something edged to pinch the tire. The "potholes" I referred to had square edges - a classic cause of pinch-flats. You can use air pressure high enough to prevent the tyre from *ever* pinch-flatting. It's just a question of whether you can stand the ride. ~PB |
#25
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Schwalbe Marathon Plus Failure
Roger Merriman wrote:
at extreme look at jumpbikes massivly reforced sidewalls to stop the tires popping. Those have to be *massively* reinforced to get the significant extra protection. With M+ and any more ordinary bike tyre, you can tell from manipulating the sidewalls with your fingers that they can't possibly put up much resistance. It's nothing compared to the forces from the weight and bumps. as i tend to at least with the workhorse run at the max prssure or above, yet can still or rather used to get pinch flats with fairly wide tires. I'm still skeptical that your differing experience was anything to do with the amount protection that the tyres themselves provided. I'm thinking maybe they were actually inflated differently, or it was just coincidence. ~PB |
#26
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Schwalbe Marathon Plus Failure
Pete Biggs wrote:
Roger Merriman wrote: A pinch flat happens when the tyre completely compresses. You can prevent that ever happening by using very high pressure. No pneumatic bicycle tyre I've ever seen or heard of will have robust enough sidewalls to prevent pinch flats. It's air pressure alone that does that job. er no, side walls are the real battle ground between duriblity and weight, I'm not taking about the durability of the sidewall here, only what difference it makes to pinching while it is still intact. no they can not do it on there own, but the stiffness of the side wall has a real differnce, I would not use lower pressure because I had more sustantial sidewalls. I don't believe sidewalls help enough in that way. The resistance to pinching that the pressurised air provides is very many times higher than anything the tyre material is doing. sometimes you need both, yes on old red, nice light tires cope fine, no problems but with the workhorse, even pumping a fair wack over the max still resulted in the odd pinch flat, marthon pluses for the same give or take air volume don't at extreme look at jumpbikes massivly reforced sidewalls to stop the tires popping. on the work horse, one could pinch flat, the rear with the land cruisers where as you'd have a job with the marthon pluses, same sorts of pressures 80 psi or higher, and big wide road tires, but the marthon's have much more substantal sidewalls. I've used tyres with delicate sidewalls that have survived potholes that were bad enough to chuck me off the bike. The tyres remained undamaged and inflated. you don't need a big pot hole etc just something edged to pinch the tire. The "potholes" I referred to had square edges - a classic cause of pinch-flats. You can use air pressure high enough to prevent the tyre from *ever* pinch-flatting. It's just a question of whether you can stand the ride. as i tend to at least with the workhorse run at the max prssure or above, yet can still or rather used to get pinch flats with fairly wide tires. ~PB roger -- www.rogermerriman.com |
#27
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Schwalbe Marathon Plus Failure
Pete Biggs wrote:
Roger Merriman wrote: at extreme look at jumpbikes massivly reforced sidewalls to stop the tires popping. Those have to be *massively* reinforced to get the significant extra protection. With M+ and any more ordinary bike tyre, you can tell from manipulating the sidewalls with your fingers that they can't possibly put up much resistance. It's nothing compared to the forces from the weight and bumps. the marthon's are fairly well reforced at least compared to the cheaper tires i had on before, nothing like jump tires though which are all about the sidewall. as i tend to at least with the workhorse run at the max prssure or above, yet can still or rather used to get pinch flats with fairly wide tires. I'm still skeptical that your differing experience was anything to do with the amount protection that the tyres themselves provided. I'm thinking maybe they were actually inflated differently, or it was just coincidence. ~PB i kept the land cruisers for a while and upped the pressures to 100PSI from the max psi of 65PSI but it still got the odd pinch flats, with the marthon + at a lower PSI of 80 or lower i've never had a pinch flat. roger -- www.rogermerriman.com |
#28
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Schwalbe Marathon Plus Failure
Roger Merriman wrote:
the marthon's are fairly well reforced at least compared to the cheaper tires i had on before, nothing like jump tires though which are all about the sidewall. A pinch flat happens when the tyre gets completely compressed. Feel how easy it is to completely compress the tyre when it is uninflated. Compare it to the inflated tyre and think how many times harder it is. The difference in resistance between the M+'s sidewalls and the skinniest sidewalls possible is dwarfed by the tremendous force of the compressed air. I'm still skeptical that your differing experience was anything to do with the amount protection that the tyres themselves provided. I'm thinking maybe they were actually inflated differently, or it was just coincidence. i kept the land cruisers for a while and upped the pressures to 100PSI from the max psi of 65PSI but it still got the odd pinch flats, with the marthon + at a lower PSI of 80 or lower i've never had a pinch flat. Something funny was going on to get pinch flats (if that's what they were) with wide tyres at 100 psi, and it was nothing to do with the sidewall, IMHO. Sometimes a problem with the rim or rim tape can cause a puncture that looks like a pinch-flat. Or you may be riding differently now, or having better luck with what you don't hit. ~PB |
#29
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Schwalbe Marathon Plus Failure
Pete Biggs wrote:
Roger Merriman wrote: the marthon's are fairly well reforced at least compared to the cheaper tires i had on before, nothing like jump tires though which are all about the sidewall. A pinch flat happens when the tyre gets completely compressed. Feel how easy it is to completely compress the tyre when it is uninflated. Compare it to the inflated tyre and think how many times harder it is. The difference in resistance between the M+'s sidewalls and the skinniest sidewalls possible is dwarfed by the tremendous force of the compressed air. lots of companies would disagree, since a fair number produce tires with reforced sidewalls, from MTB to BMX and all between, and around. we are not talking 200PSI here but 80PSI most tires have a bit of give at that pressure, marthons compared to some tires give a much harsher ride, for given pressure, compared to the three types of tires on before the Marthon pluses are harsh, not just I rereviews it comes up. I'm still skeptical that your differing experience was anything to do with the amount protection that the tyres themselves provided. I'm thinking maybe they were actually inflated differently, or it was just coincidence. i kept the land cruisers for a while and upped the pressures to 100PSI from the max psi of 65PSI but it still got the odd pinch flats, with the marthon + at a lower PSI of 80 or lower i've never had a pinch flat. Something funny was going on to get pinch flats (if that's what they were) with wide tyres at 100 psi, and it was nothing to do with the sidewall, IMHO. as almost all my weight is on the rear, with all the gear in the paniers the bike is 50lb unlaided, i don't hang about nor care too much with that bike as to speed bumps etc, even with the pluses you can feel a fair amount of give as the tire deflects a bit, i'm fairly brutish to that bike as it's the work horse, it gets the job done. Sometimes a problem with the rim or rim tape can cause a puncture that looks like a pinch-flat. Or you may be riding differently now, or having better luck with what you don't hit. unlikely as I feel the rim hit, much as one would pre suspention going though rock gardens if you fluffed your line. ~PB roger -- www.rogermerriman.com |
#30
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Schwalbe Marathon Plus Failure
Roger Merriman wrote:
A pinch flat happens when the tyre gets completely compressed. Feel how easy it is to completely compress the tyre when it is uninflated. Compare it to the inflated tyre and think how many times harder it is. The difference in resistance between the M+'s sidewalls and the skinniest sidewalls possible is dwarfed by the tremendous force of the compressed air. lots of companies would disagree, since a fair number produce tires with reforced sidewalls, from MTB to BMX and all between, and around. Except in special cases for special bikes, sidewalls are reinforced to make the sidwalls more durable, not to make the tyre more pinch-flat resistant. Skinwalls are prone to getting cut and split. we are not talking 200PSI here but 80PSI most tires have a bit of give at that pressure, Of course there is give, but it takes many more times the force to get that give (compress the air) than it takes to compress the sidewalls. Try completely compressing your tyres at 80 psi with your fingers (you won't be able to). Now try at 0 psi (you will be able to easily). Note the huge difference. That alone should prove to you that the sidewalls can do hardly anything to prevent pinch flats. The force from your fingers is nothing compared to the force of hitting a bump with your weight on the bike. marthons compared to some tires give a much harsher ride, for given pressure, compared to the three types of tires on before the Marthon pluses are harsh, not just I rereviews it comes up. The whole tyre material, not just the sidewalls, contributes to rolling resisance and how harsh a tyre feels. M+ has an unusually thick layer under the tread. But still it's very little compared to the resistance from compressed air. I didn't notice very much difference anyway when comparing M+ to Specialzed Nimbus EX. (Same bike, same size tyres, same pressure). The Nimbuses have skinny sidewalls. I'm still skeptical that your differing experience was anything to do with the amount protection that the tyres themselves provided. I'm thinking maybe they were actually inflated differently, or it was just coincidence. i kept the land cruisers for a while and upped the pressures to 100PSI from the max psi of 65PSI but it still got the odd pinch flats, with the marthon + at a lower PSI of 80 or lower i've never had a pinch flat. Something funny was going on to get pinch flats (if that's what they were) with wide tyres at 100 psi, and it was nothing to do with the sidewall, IMHO. as almost all my weight is on the rear, with all the gear in the paniers the bike is 50lb unlaided, i don't hang about nor care too much with that bike as to speed bumps etc, even with the pluses you can feel a fair amount of give as the tire deflects a bit, i'm fairly brutish to that bike as it's the work horse, it gets the job done. Sometimes a problem with the rim or rim tape can cause a puncture that looks like a pinch-flat. Or you may be riding differently now, or having better luck with what you don't hit. unlikely as I feel the rim hit, much as one would pre suspention going though rock gardens if you fluffed your line. A big impact with a hard tyre can feel lke the rim is hitting when it actually isn't. But if the rim really is hitting then you need even higher pressure. +10 psi will make far more difference than that from different sidewalls. I feel sorry for your wheels! :-) ~PB |
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