Nothing too major... But today I went to go to class and my tire was dead flat. I hadn't ridden it for a week, but eh. Anyways I pumped it back completely full, and after 12+ hours it was still completely full.

Is there any reason why it randomly went flat? Should I replace the tube to be on the safe side? I don't want to get stranded if it's going to crap out on me. I don't like changing the tube, but if it's best to do so I will lol

Do you have a roommate inclined to mischief? Barring that I'd wager a slow leak that takes longer than 12 hrs.

My room-mate wouldn't do that, eh, will see how the tire is in the morning.

I have a tire that takes about a week to go flat.
I suspect it's the valve.

Something you can do. Take the tube out and figure out how it is arranged vs the tire. Inflate the tube and stick it under water. You should be able to detect a slow leak by finding where the bubbles come out. Then knowing where on the tube the hole is, go find the same spot on the tire and see if the offending object is still there. I have had a few flats that were caused by those tiny steel wires that are in steel belted auto tires. They are almost invisible and are very difficult to find on a tire unless you know exactly where to look. Sometimes small slivers of glass behave the same way. Of course, you could just pitch the tube and replace it and hope that your luck holds.

Could just be a slow leak.

After reading 'Obscure flat tire', I was expecting to read about a puncture on the bike of a guy nobody knows in some place no-one has heard of.

Either the valve came loose, or you have a slow leak on your hands.

Something like that happened to me, once. I had pumped up the tires and then gone for a ride, with no problems. The next morning, a tire was absolutely, totally flat. The bike had spent the night in my apartment, with nobody but me present, so there was no possibility of a prank. I pumped up the tire, and it never had a problem again. My guess is that there was a tiny speck of dirt in the valve.

I suspect it's the valve.

valves can be replaced easily.

I agree with the "speck of dirt in the valve" theory. Other than that, you have a slow leak that can be detected in the sink. Some of these may only release a tiny bubble every two or three seconds, so watch carefully.

Dirty little secret: bike tubes are terrible. Many of them have slow leaks right out of the package. A small enough leak, in an unlucky place can be intermittent also. I suppose because of the tube flexing ever so much inside the tire from time to time. This is magnified by the fact that there is so little air volume in a bike tire, so a little lost air makes a large pressure difference.

A stuck valve is possible too.

jim

Flats happen and are easily repairable.

My tyres will lose about 10psi a week They will then get so low if I do not pump them up before each ride that the thorn that is still in the tyre will not be filling the hole in the tube and it will then go down overnight.