Tire pressure
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His implication is that he's faster as a direct result of the pressure, whereas others feel that he may be faster as an indirect result (road feedback can alter perception, which can affect performance); RPE isn't enough of an equalizer.
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But he may be faster because he is pedalling harder because he feels better. That completely changes the information we gain about tyre pressure.
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No, it is worthless because you have no idea whether or not you just put out more power, exactly because you say you felt better with harder tyres. As I already said and as you conveniently ignored, it is common knowledge that harder tyres feel faster. That definitely can make you feel more comfortable and pedal harder.
Do the test with a power meter and get back to us, I would actually be interested in that.
Do the test with a power meter and get back to us, I would actually be interested in that.
Besides, there wasn't that much difference in the data I collected. However for both the entire routes ridden and for climbs and the few fairly flat places that I do at near max effort that I segmented out of the data, then lower pressure tires were slower. But not much.
I'd think that the fact my legs were more tired with the lower pressures than they were the higher pressures is a valid perception that one needs to consider. Or should I call foul on all those that say their ride is more comfortable with lower pressure because it's known that lower pressures in tires generally smooth out the bumps?
When I had the old Continental Ultra Sport tires from circa 2009 (the new Ultra Sports are different construction) on my bike they were uncomfortable at any PSI. I even rode them at 75 psi all the way up to and beyond their max recommended pressure of 95 PSI, IIRC. They were horrible riding tires. When I moved to the Vittoria Rubino Pro's and Continental GP5000's, I noticed right off the bat that they were more comfortable at even extremely high PSI than the Ultra Sports were at the lowest possible pressure I could ride them without getting a pinch flat regularly.
You seem to be hung up on power. To me all power would do is show me that something else is responsible for the griping my legs did for 12 - 14 rides. So does that matter so much? I always thought that time between point A and point B is what matters.
I'm also not suggesting the current science of tire pressure is wrong. I pretty much agree with it. However people misuse it. For those favoring Silca's calculator, it's interesting that they show a 25 or 28 mm tire should use lower pressure with a butyl tube than a tubeless tire. Something is off in their thinking or their calculator. Or perhaps I'm totally just not understanding things.
But why people wish to blindly do what a calculator tells them and say they are happy is beyond me. I at least experiment and find out what I like and what works for me well.
Last edited by Iride01; 08-14-22 at 01:54 PM.
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I don't think your legs were more tired at 90 then 120. It's impossible. It's not like you were using 2.5" tires at 10psi. I don't believe what you think happened is actual fact. Sorry.
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I've tried a number of tire pressure calculators and find they are all good starting points. Ultimately I go by feel. I've been riding 700x28 at 75 rear and 60 front psi. Today I bumped up the rear to 80 psi as I keep feeling like the rear was a little to squishy. I'm using Continental GP5000 with butyl tubes
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In these pressure threads, everyone can be right at the same time; after buying a couple of fairly inexpensive digital pressure gauges I found that the gauge on my pump was showing a bit over 10 psi more.
Last edited by Branko D; 08-15-22 at 03:05 PM.
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Overbeaten topic... Higher pressure may feel faster, but it is not. Science proven.
Wider tires & lower pressure is the current thing (yes, it will most likely change in a few months/years). At 165lbs, I ride my 28mm TL tires at 65PSI and I love the feel. t will most likely be outdated in a few years.
Wider tires & lower pressure is the current thing (yes, it will most likely change in a few months/years). At 165lbs, I ride my 28mm TL tires at 65PSI and I love the feel. t will most likely be outdated in a few years.
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Why don't you do the test for yourself? It really won't mean anything for me to do the test for you because my conditions are unlikely to be your conditions. I'm loathe to do the test again because I absolutely did not like how exhausted I was left feeling after a ride, even a short ride on the lower PSI tires. Oh, and by the way, be certain you do 12 rides or more of each set tire pressures you choose to compare. That will have more evidence behind it that simply a ride or two.
Besides, there wasn't that much difference in the data I collected. However for both the entire routes ridden and for climbs and the few fairly flat places that I do at near max effort that I segmented out of the data, then lower pressure tires were slower. But not much.
I'd think that the fact my legs were more tired with the lower pressures than they were the higher pressures is a valid perception that one needs to consider. Or should I call foul on all those that say their ride is more comfortable with lower pressure because it's known that lower pressures in tires generally smooth out the bumps?
When I had the old Continental Ultra Sport tires from circa 2009 (the new Ultra Sports are different construction) on my bike they were uncomfortable at any PSI. I even rode them at 75 psi all the way up to and beyond their max recommended pressure of 95 PSI, IIRC. They were horrible riding tires. When I moved to the Vittoria Rubino Pro's and Continental GP5000's, I noticed right off the bat that they were more comfortable at even extremely high PSI than the Ultra Sports were at the lowest possible pressure I could ride them without getting a pinch flat regularly.
You seem to be hung up on power. To me all power would do is show me that something else is responsible for the griping my legs did for 12 - 14 rides. So does that matter so much? I always thought that time between point A and point B is what matters.
I'm also not suggesting the current science of tire pressure is wrong. I pretty much agree with it. However people misuse it. For those favoring Silca's calculator, it's interesting that they show a 25 or 28 mm tire should use lower pressure with a butyl tube than a tubeless tire. Something is off in their thinking or their calculator. Or perhaps I'm totally just not understanding things.
But why people wish to blindly do what a calculator tells them and say they are happy is beyond me. I at least experiment and find out what I like and what works for me well.
Besides, there wasn't that much difference in the data I collected. However for both the entire routes ridden and for climbs and the few fairly flat places that I do at near max effort that I segmented out of the data, then lower pressure tires were slower. But not much.
I'd think that the fact my legs were more tired with the lower pressures than they were the higher pressures is a valid perception that one needs to consider. Or should I call foul on all those that say their ride is more comfortable with lower pressure because it's known that lower pressures in tires generally smooth out the bumps?
When I had the old Continental Ultra Sport tires from circa 2009 (the new Ultra Sports are different construction) on my bike they were uncomfortable at any PSI. I even rode them at 75 psi all the way up to and beyond their max recommended pressure of 95 PSI, IIRC. They were horrible riding tires. When I moved to the Vittoria Rubino Pro's and Continental GP5000's, I noticed right off the bat that they were more comfortable at even extremely high PSI than the Ultra Sports were at the lowest possible pressure I could ride them without getting a pinch flat regularly.
You seem to be hung up on power. To me all power would do is show me that something else is responsible for the griping my legs did for 12 - 14 rides. So does that matter so much? I always thought that time between point A and point B is what matters.
I'm also not suggesting the current science of tire pressure is wrong. I pretty much agree with it. However people misuse it. For those favoring Silca's calculator, it's interesting that they show a 25 or 28 mm tire should use lower pressure with a butyl tube than a tubeless tire. Something is off in their thinking or their calculator. Or perhaps I'm totally just not understanding things.
But why people wish to blindly do what a calculator tells them and say they are happy is beyond me. I at least experiment and find out what I like and what works for me well.
I don't want you to do it for me, I have hookless rims, I cannot go above 73 psi anyway. I was genuinely interested in your results with power as an objective baseline.
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I'd still think you'd want to do a test for yourself. It's what I'd encourage everyone to do. Find the pressure that works best for them within the limits of their recommended max tire pressure. You'll know better than a calculator that can't take everything into consideration. The Silca calculator doesn't take my conditions or tires into account IMO.
I was well within my max limits when I did my testing. IIRC the max PSI for the tire is 135 psi. Maybe 125 psi.
Last edited by Iride01; 08-15-22 at 03:20 PM.
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No, but you were the only person to on two occasions that stated my results were worthless.
I'd still think you'd want to do a test for yourself. It's what I'd encourage everyone to do. Find the pressure that works best for them within the limits of their recommended max tire pressure. You'll know better than a calculator that can't take everything into consideration. The Silca calculator doesn't take my conditions or tires into account IMO.
I was well within my max limits when I did my testing. IIRC the max PSI for the tire is 135 psi. Maybe 125 psi.
I'd still think you'd want to do a test for yourself. It's what I'd encourage everyone to do. Find the pressure that works best for them within the limits of their recommended max tire pressure. You'll know better than a calculator that can't take everything into consideration. The Silca calculator doesn't take my conditions or tires into account IMO.
I was well within my max limits when I did my testing. IIRC the max PSI for the tire is 135 psi. Maybe 125 psi.
I ride tubeless, so I every time I am not bothered to pump up I can test lower pressures. I feel a difference below 4 bar but not much between 4 and 4.5, which is already 65 so close to the limit so that is where I pump it to. FWIW that aligns well with SRAM's calculator that suggests 61 front and 65 rear. On long rides I pump up to just above 4, as that feels like a good mix between speed and comfort. When I go for a PR on my local climbs I go maybe 4.2 or 4.3.
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That was not a personal attack but an observation. Your results are not useful for a general statement about this topic. They are useful to you. The reason being is that your main points are that you feel more comfortable and you are faster. Neither of those is objective and transferable to others. With a power meter you would have an objective frame of reference that would make it useful to others.
.
.
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What the science shows is that there is a theoretical optimal pressure for any given combination of rider, equipment and road surface. What people make of that varies.
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That was not a personal attack but an observation. Your results are not useful for a general statement about this topic. They are useful to you. The reason being is that your main points are that you feel more comfortable and you are faster. Neither of those is objective and transferable to others. With a power meter you would have an objective frame of reference that would make it useful to others.
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All this give and take and anecdotal evidence is absolutely worthless without knowing the weight of the rider. Better yet, also the weight of the bicycle and whatever load it's carrying. A 140 pound person on a bare-bones racing bike is not anywhere near the same as a 215 pound rider on a heavy bike. And of course the tires size. Just asking for, or just giving one's personal preference of tire pressure without any other information is absolutely worthless.
Last edited by Camilo; 08-16-22 at 12:31 AM.
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First get a new pressure gauge, so you know what pressure is really in your tires. Too low with tubed tires will result in pinch flats. Use the pressure calculator at zipp.com. There's no reason for the rear tire to have 10-20 psi more pressure.
Best change I've made is to have frames that can use at least 28mm tires. Many now fit up to 32. Wider rims are also wise. I'm running the new Zipp 303s hookless rims that have an internal width of 23mm. With 30mm tires, I use 54/57 psi. The tires measure 31.5mm inflated.
Best change I've made is to have frames that can use at least 28mm tires. Many now fit up to 32. Wider rims are also wise. I'm running the new Zipp 303s hookless rims that have an internal width of 23mm. With 30mm tires, I use 54/57 psi. The tires measure 31.5mm inflated.
Last edited by Camilo; 08-16-22 at 12:30 AM.
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What if he had a power meter, and it showed that he produced fewer watts with the lower pressure tire. Or he did indeed output the same watts. Or he produced more watts on the lower pressure tire? But nonetheless he was faster therefore on the more inflated tires. How exactly would another person make use of this information and apply it so as to know whether to add, subtract or leave unchanged, their current tire pressure?
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That was not a personal attack but an observation. Your results are not useful for a general statement about this topic. They are useful to you. The reason being is that your main points are that you feel more comfortable and you are faster. Neither of those is objective and transferable to others. With a power meter you would have an objective frame of reference that would make it useful to others.
A PM would have added some more data to consider. However I don't think that a PM will answer the OP's question.
In my reply to cxwrench I made the statement that my tire pressure gauge might be off. Yet you blast me for giving an honest opinion of my results because they don't include a PM. If anything I'd think I'd get blasted for not having checked the accuracy and precision of my gauge!
The data I collected is fact. The perceived effort I felt is fact within my own personal frame of reference. My use of that data that I shared with others is simply opinion. A power meter would not have changed the results of my findings. It might give some credence one way or the other toward some of the observations.
You seem to object to me stating I was faster on something that goes against the science you believe. I pretty sure it's the same science I believe. Only you, like some others believe all that science is contained in some online calculator for tire pressure that does not have all the variables.
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The only reason you use the pressure you do is because you think you're faster? How long is the ride and what were the time differences? Rolling resistance is by far the least difference and the last reason you should ride lower pressure. Traction? Better at lower than you're using. Ride quality? Better at lower than you're using. Those points can not be argued.
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Wasn't this question by the OP in the very first post the topic? You didn't seem to blast others for giving their opinion and not saying if their observations were based on a PM.
Seems my first reply did exactly that.
A PM would have added some more data to consider. However I don't think that a PM will answer the OP's question.
In my reply to cxwrench I made the statement that my tire pressure gauge might be off. Yet you blast me for giving an honest opinion of my results because they don't include a PM. If anything I'd think I'd get blasted for not having checked the accuracy and precision of my gauge!
The data I collected is fact. The perceived effort I felt is fact within my own personal frame of reference. My use of that data that I shared with others is simply opinion. A power meter would not have changed the results of my findings. It might give some credence one way or the other toward some of the observations.
You seem to object to me stating I was faster on something that goes against the science you believe. I pretty sure it's the same science I believe. Only you, like some others believe all that science is contained in some online calculator for tire pressure that does not have all the variables.
Seems my first reply did exactly that.
A PM would have added some more data to consider. However I don't think that a PM will answer the OP's question.
In my reply to cxwrench I made the statement that my tire pressure gauge might be off. Yet you blast me for giving an honest opinion of my results because they don't include a PM. If anything I'd think I'd get blasted for not having checked the accuracy and precision of my gauge!
The data I collected is fact. The perceived effort I felt is fact within my own personal frame of reference. My use of that data that I shared with others is simply opinion. A power meter would not have changed the results of my findings. It might give some credence one way or the other toward some of the observations.
You seem to object to me stating I was faster on something that goes against the science you believe. I pretty sure it's the same science I believe. Only you, like some others believe all that science is contained in some online calculator for tire pressure that does not have all the variables.
If I objected to you stating something that supposedly goes against my beliefs, why did I reply to a very specific later comment, and not the original statement? Answer is I didn't really have anything against your original statement.
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I didn't blast you at all. What personal thing did I say about you? If a scientist does a study and someone criticises the method, is that a personal attack on the scientist? Only someone with a shallow ego would take it that way.
If I objected to you stating something that supposedly goes against my beliefs, why did I reply to a very specific later comment, and not the original statement? Answer is I didn't really have anything against your original statement.
If I objected to you stating something that supposedly goes against my beliefs, why did I reply to a very specific later comment, and not the original statement? Answer is I didn't really have anything against your original statement.
Now because I used the term "blast" you try to turn this back on me as sounding like I'm the problem in this conversation?
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