Tire Air Pressure drop?

[RoaringTodd]

Hello All -

I have new Vee rubber tires, installed in the spring. Last Saturday at the rally, I was sure to inflate my tires to 30 psi as recommended on this site.

Today, I rode to work, and when I checked the PSI after the ride - ( only 1.2 miles one way) the pressure on the rear tire had dropped to 20psi. That is quick, for a 10 psi drop over 4 days.

Does anyone know if this is normal, and what I should look for?

Tubed tires, 3.5x10

Checked for punctures. Did not see any.

Thanks for any advice -

RT

[BeefSupreme]

Spray bottle full of dish soapy water, cover the entire tire... take off the valve stem cap and spray as well, look for bubbles. If there's a leak you'll see it. Mark your leak and go from there, hopefully you just have to tighten your valve stem.

[Tocsik]

+1 on valve stem. You may get lucky and it's the valve mechanism inside the stem just needs tightening. Do you have a valve stem tool? Some valve stem caps have them built-in.

If you've already checked for a puncture (I assume with the soap+water method) use the same soap solution on the valve stem and be sure it's not torn down near the wall of the rim. Was it replaced with the tire? Sometimes you can just use plain water without the soap and see bubbles. Saves on the messy aspect.

I actually lost all pressure in my tire at work one day. Wife came and picked me up in the truck and when I got home, I finally realized it was just a loose valve stem body. It's now one of the first things I check when I think I'm losing more air pressure than seems reasonable.

Another option is that the tire bead didn't get seated on the rim all the way.
If you have an air compressor (not of the little portable cigarette lighter plug ones) you can take out the valve stem body to let all the air out of the tire then re-inflate to re-seat the bead. Sometimes you have to inflate much higher than the typical pressure you run in the tire to seat the bead. Don't go too high, though.