Weird tire-pressure anomaly

[lilies]

Couple days ago, before going shopping, I checked my bicycle tires pressure by hand and found that I could quite easily press my thumb into both tires. OMG, these are way too soft and probably have been steadily deflating! While visually the tires weren't flat at all. They just felt so soft under my squeezing fingers.

Immediately I remembered the increased amount of broken glass pieces [booze] on the side-roads at a couple places days ago. I must have ran over them and the tiny glass shards probably made tiny punctures, so I was already planning to go to the bike-repair shop to have both rubber tubes replaced.

Just to test, how fast the tires deflate, I pumped air into them, until they got "hard enough" and went shopping on the bike. Since I use a 30 year old bike & probably an even older pump, I never had any air pressure gauge at all. Last year the repair-shop guy tried to convince me to buy their pricey air-pumps with built-in gauges and scolded me telling about "bikes should be ridden only with precise tire air pressure values", I just laughed. I did beautifully for 30 years biking without precisely measuring air-pressure..

However this time I had difficulties pumping the tires, "until they got hard".. Didn't matter, how much I pumped, I always could press my thumb into the tire rubbers.
Impossible!
Also I was afraid, I would over-pump these old tires and they would blow out..

So I settled on a reasonably weird rubber tire "hardness", which I couldn't really determine by hand, because both tires remained strangely way too soft. So in the end I just let it go..

I even got suspicious, for this weird 'confusion about muscle strength fluctuation' occurred couple times already in the past years. Feats of strength - while working outside - I didn't even notice: people just asked me confused "How did you do that?"
So I tested my fingers strength on a wooden plank and while it bent, I clearly couldn't break it. So I concluded, I didn't develop anomalous temporary strength. Probably it was just high blood sugar..

Days later, - this Monday - I hand-tested the same tires - that I never pumped air into again since the incident - and they felt rock hard. Cautiously I felt them and it appeared I couldn't press my thumb into the rubber again. Both tires seemed properly pressurized. Then on Tuesday and today I tested again with my hand and the same tires were rock-hard holding their air pressure. Now, in the warmer weather. Compared to winter, when they were always rock hard. The same pumped up tires that felt way to soft = easy to press my fingers into like 5 days ago are felt rock-hard now without pumping any more air into them..

I always pay attention to ride my bike with adequately high air-pressure all the time, since the repair-shop guy showed me that he pumped the tires super-hard to a precise gauge-value and he declared this insane hardness is the baseline.

I even remembered that I brought these same tires back to the shop like a year ago, telling the repair guys: "they felt soft and I couldn't pump them up." The guys there pumped the tires with a gauge to a precise value and sent me home.

Was it high blood-sugar that made my fingers stronger temporarily?
During exercises - doing the very same number sets and same running distances for years, I noticed fluctuating endurance levels on occasions earlier, but didn't pay much attention.

 

[Cosmos]

Was the surrounding air temperature where the bike stood the first time noticeably different compared to the surrounding air temperature when the tire felt „harder“ the second time? Was it warmer or colder?

Have you checked all possible explanations why you couldn’t pump air into the tire? Maybe the pump was leaking the air (not airtight anymore) and thus you couldn’t fill the tire even though it seemed/felt like you pushed air normally into the tire?

5 Things You Should Know About Tire Pressure

Fine-tune your air volume for a free way to boost your bike ride

www.bicycling.com

 

[lilies]

It fluctuates as temperatures change
A good rule of thumb is that a 10-degree change in Fahrenheit will increase pressure roughly two percent, says Silca’s Josh Poertner, who probably thinks about tire pressure more than anyone. For roadies, that means roughly 2psi for every 10 degrees up or down from whatever temperature it was when you inflated your tire.

That must have been it then. The storage room temperature where I keep the bike is always warmer than the cold outside: I always inflate the tires in the warmer storage room.

Its an old pump, so I hold it down with an old combination plier by stepping on it with one foot, so I can hear the hiss of air entering the tires. 10 quick pushes usually does it with the pump.

So as the weather and temperatures fluctuate, the tire may feel soft one day then hard the next day: if from 45°F / 7°C in the morning it warms up to 67°F / 20 °C during the day, then according to the linked article that's a 4psi difference, which must have been what I felt as "too soft" by hand.

Its just this crazy weather then, causing wildly flinging temperature differences.

 

[Metrist]

Sometimes, especially on the rear tire, the tire loses its integrity, and the ride feels squishy. And air pressure won't fix it. The tire is just worn out - like the plys are not keeping the tire in form properly.
I usually buy a new rear tire every year. The front doesn't wear out so fast, and they last a lot longer.
Sometimes the road is bumpy and it feels like you should check it, but it was just little rocks or bumps causing concern.
Another thing... the innertube might be bound up and kinked - some tubes seem to be larger than others and so the tubes get kinked when you put them in. I always put a little air in, then roll the tires to roll out any binding.

 

[Haiku]

Pressure anomalies. You looked to temperature for the reasoning here. I suspect that it is barometric pressure affecting all in this reality. I have been monitoring an unusually low pressure at my home. And it has been going on for about 6 months now. My digital gage was continuously recording numbers around 980-985 mmHg. I thought it might be in error, so I bought a small mechanical barometer gage to compare with my digital meter. But it did not show any deviations between the two gages, they correlated pretty good as a matter of fact. This was concerning as I can bring up the local weather from many sources and it states something much higher than I am reading on my gages.

Now your tires are pressurized and gaged via an offset of about 14.5 PSIA (that is PSI Absolute) or 1000mmHg. The tire pressure gage is not affected much by atmospheric changes. But a higher barometric pressure could make your tires feel softer than the pressure gage states. And likewise, the lower barometric pressure makes tires feel harder while the tire pressure, via the tire gage, has not changed at all.

Now it is not a lot, but we humans are very sensitive to these items. When the feeling of a touch changes, we notice. I get this on assembly lines when a user notices something that does not feel right with what they are assembling. I look into it and find something like a calibrated tool that is deviating from its settings. We are sensitive to touch as we are to smelling the fragrances of nature as they change.

No, we are not going super-human here. Just the human’s sense of felling is quite sensitive to change. We may also be ultra-sensitive feeling this as to our awaking’s of this reality. Likewise, with all of our other senses and emotions as we engage the incoming wave. We are feeling more, Haiku …