hello I am having trouble inflating my back wheel tube. so i guess i will just tell you what happened. well i came back from the bike shop with a presta valve adapter and i put it on my tube. it fills up too near full psi but just after a ride around the block it is flat. i have no idea why. please help me! also its a mavic tube 700 x 23, vittoria rubino pro 700 x 23 tire, and a vuelta xrp 17 deep v back wheel. thanks!
You have a slow leak. You need to pull the tube and patch the hole or replace the tube.
Did you take the adapter off? It is only intended to fill the tire, you take it off and close the valve.