My tire is gradually losing air. I pump it up and two hours later its deflated. I take the tube out of the tire pump it up with air, and the air holds. I'm not sure whats going on. The only thing I can think of is that I have a pin hole in the tube but I can't find a hole.... but I recently put on Armadillo tires and was hoping to get better protection for my tubes. I'm thinking I may have to inflate the tube then stick it under water to try and find a hole...

Any ideas as to whats going on?

do this

Yes it will help if you put the tube under water. It may be a leaking valve.

In any case I would just get a new tube, since they're so cheap.

Luke

the problem must be with the tube right? how can i stop these from happening? ive had the bike maybe a month and have been through 8 tubes already. Im not exaggerating either. I have pretty good tires on the bike and always keep them inflated toe 110 psi. i guess maybe i ride to rough over bumps and what not?

any advice would be great...

check the tire for something in it. use a rag , run it in side and if it snug you found it, remove whatever it is. if the hole bother you can cover it with duct tape (inside of the tire ).check your valve it maybe lose. if you find the hole in the tube patch it, with a patch kit. if water doesn't work you can always hold the tube up to your face and feel the air leaving the tube or use soapy water and look for bubbles this goes for the valve too.you could add a liner for the tire too.

very slow leaks can only be found under water....
if its not the tube then it has to be a loose valve stem.