at a very slow pace, of course, but it happens. even while just sitting idle.
i bought the road bike and took it to the kitchen for a tune up. it was in decent shape and all i had to do was adjust the derailuer, set the brakes and lube it up. i also trued the front wheel, sort of as it was my first attempt ever, but i left the back wheel as is because it didn't seem too off and i had almost overstayed my welcome by truing for nearly an hour.
after about a mile and a half i noticed the back dragging and stopped at a bike shop which was luckily a block away. the back tire was completely flat by the time i got there. the guy replaced the tube and i found out there was no rim tape in either wheel. by the time i left, i obviously had spent much more than i planned...
since then, everytime i take it out i have to add air before i get going. it's not a constant flat, but there's always a definate difference in pressure between it an the front. both tires on the bike seemed to be brand knew when i got it and after the shop guy and i both checked inside for objects and found none, it still looses pressure.
could it be the truing that i neglected? what on earth could it be, i ask!