Hi everyone. I have just got my first bicycle in a long time. The LBS I got it from said that they had already checked it over and everyhting was good to go. My problem is with the gears. I don't think that I am not really understanding. I can go up hills ok so that isn't my problm. When I am on flat ground or going down hill it is almost like my pedaling isn't serving a purpose? Almost like the front tire is off the ground and I am pealing. Does anyone have any ideas what could be going on?