I'm using the fixed gear so it's not the freewheel problem. I took the rear brakes off so that's not the problem either. Chain tension seems ok as well. The noise is very consistent, almost like the noise the freewheel makes on a normal bike when you coast (the clicking sound), and it is louder when I use my feet to slow the bike down. At any rate, if it's not a big deal I'm pretty sure I can ignore it and continue riding. I was just afraid that it might be a problem with the hub or the way the wheel is built or something big that I might be concerned about.