Something strange happend today.

[audiviruz]

So today I was going to the barber shop so I decide to go on the bike. Upon my inspection I notice that the tires were low on pressure just a few pounds. So I went to the gas station and put in a few pound of pressure.

I arrive at the shop and parked the bike. When I was done a hour and a half later I got out and leave. As I rode away I notice something strange with the steering like I had a flat. So I pulled over and check the front tire and sure enough the tire was all most flat. So I thought for a second, what do I do I'm a few miles away from home and no gas station in sight. So I decide to limp it home I went slow and I was scared. But I got home safe.

When I got home I check the tire to see if had a hole in it, but i found notting I needed to leave so I put in a few pounds of air pressure and left the bike home. When I came home about four hours later I check the tire and it was fine, no change in pressure.

So what the hell happend? When I filled the tire the first time I didn't put on the air valve cap on. Would this cause the tire to lose air pressure? Or was someone messing with the bike while I was in the shop?

[nitros222]

Most likely the valve core on the inside of the valve stem stuck. they do that sometimes if either it gets bent or gets dirt in there. No you will not loose air if the cap is not on. But the cap does keep dirt and stuff out.

[shogun1011]

wow..that is strange. I've never known tires to lose pressure because the cap was off. I've actually experienced something similar to that with my car once. I went through a touchless carwash with it, pulled away from the car wash to dry my car...about halfway through drying it, i noticed the front tire had lost lots of air. i drove it about a block away while i still had a chance, pulled into townfair tire, and had them patch the tire. When they were all done they told me that they couldn't find anything wrong with the tire. I had a tire cap on it at the time. That tire lasted me a whole year after that, and then i changed them because of wear.

?? I'd say you shouldn't get your hair cut anymore.

[audiviruz]

Most likely the valve core on the inside of the valve stem stuck. they do that sometimes if either it gets bent or gets dirt in there. No you will not loose air if the cap is not on. But the cap does keep dirt and stuff out.

Should I replace the valve core? I do have some in my tool shed.

[thecynic]

It's not uncommon for gas station air pumps to 1) only pump out 10-20psi, 2) have badly calibrated(or not operational at all) guages. I would lean towards blaming the pump you used.

If the tire DID get pumped up to the correct level then went down, I would suggest taking the valve core out and replacing it. Make sure the little rubber rings on the new ones look good, I would also take a few Q-tips with brake clean on them to the inside of the valve stem while the core is out since it is almost always dirt in the valve stem that causes these problems, not the valve core itself.

[nitros222]

sometimes the cores just stick probably a good idea to replace it

[audiviruz]

I'll replace the the core and clean out the inside of the valve.

Thanks
Everyone

[The CyberPoet]

Good move.

Other things to know:
If you travel particularly fast (triple-digit speeds), always use a valve cap. The force pressing outwards applies to the valve stem too, and a weak valve spring may open just enough to slow-leak at very high speeds.

If the tire is low again tomorrow, soapy water will help you find the leak -- make sure you also check the valve stem itself.

Cheers,
=-= The CyberPoet

[Mojoe]

whenever you go add ait to a tire, on a bike or a car, it is ALWAYS a good ide to put a bit of spit on your finger wipe it into the valve stem. If the valave did not seat properly, you will see it bubble.
I run powder in my tires for balancing, so this problem has happened to me before by it jamming in my valve.
if you do add air and check if it is leaking like I mentioned, and find that it is, usually another little shot of air will seat the valve.

[md86]

Mine used to do this quite often . That's why I got into the habit of checking pressures EVERY day before rding . I'd go out , and the front would be flat . Fill it up , and it'd be fine . Then it'd be flat again the next day , fill it up , and it's fine . Stays fine for a MONTH , then randomly goes flat again . Happened with SEVERAL different tires . I just check them often .