i had a flat couple of days ago, and come to find out there was two industrial size staples in there pretty good.so for a piece of mind i decided to replaced my rear tire.to make a long story short ,tire is on , and wheel is on now and bike is on stand but when i roll the rear wheel i'm not sure if i'm hearing a strange noise it the rear axle..is there supposed to be aslight noise from the rear bearings and some chain noise or not???????????