It's a slow leak.
Here's my details
I bought a used bike last year-Summer 2006. And I just change to new inner tubes for the front and the back tires
last 3 weeks ago. I've been riding this bike since I changed inner tubes. I put air in at the same rate that shows on the tires. I did every thing almost exactly.
Then yesterday, I checked my tires and prepared for ridding to work today. I found that the air pressure of the front tire wasn't normal and it seemed like it lose a lot of air. Then, I put the air in again last night. This morning I checked it again. Then the air is almost gone. But this morning I had to ride my bike to work. Then I fill air in. And I can ride it now. But maybe after I get off my work, I will have to find the air pump.
Is it possible because of its tire? I got them last year around summer. I used it for 3 miles a day during summer 2006. But now I ride about 8 miles a day. I also ride it on the wet yard too.
Thank you everyone.