Which rim numbers are what i need looks like back one with sprocket and tire is #astrowheelassy60 then there is 2 numbers i can not tell what the difference is other than the price #az1128 for 49.99 and #az1129 for 60.95 other than the 1129 having not as good of bearings whats the difference? i cannot even tell which are front or rear choices even. this is from our OldMiniBikes web store