Joined: Jul 2002
Posts: 40,863
Likes: 3,115
From: Sacramento, California, USA
Bikes: Specialized Tarmac, Canyon Exceed, Specialized Transition, Ellsworth Roots, Ridley Excalibur
You have a slow leak. Pull out the tube, find the hole by inflating the tube and dunking it in a bucket of water, then patch the hole. Before putting the tube back in the tire, run a cotton ball along the inside of the tire. It will snag on a tiny piece of wire or glass, if that's what's causing the leak.