I just wanted to post an update. It seems the problem must surely have been that the man at the bicycle shoppe had twice put in the wrong sized tube without my knowledge. Once the correct size tube was installed the bike didn't get any problem with the tube bursting and the tire going flat. The tires seem okay now. I have a regular-style bicycle pump and put some air in when it needs it. I don't use that hand-held type pump any more and so the tire tubes aren't getting the valve snapped off by the hand-held pump. I've taken my bike out a few times over the past couple months, whenever weather was permitting, and it's okay, just except for the brakes but I don't know anything about bicycle maintainance so I don't know how to administer to that. The bike has only hand brakes and no pedal brakes. I can only use the brake on the right handlebar because my left hand is disabled. Shortly after I got the bike it started making a very loud rubbing noise whenever the brakes were applied. I keep the bike covered with an old car cover on my porch but it still managed to get some rust on the brake cables and the chain. I'm not sure what I should do about that or what, if anything, could be done to make the brakes quiet. The noise is embarassing. The bike is only one-speed and goes rather slow (only about 10 miles an hour) no matter how fast you pedal but I rarely pedal that fast and usually cruise gently with it so I don't know why the brakes are making that awful noise. Could it be due to the fact I can't apply brakes on both handlebars?