The link you provided says the wheel is 130mm spacing for 5, 6, 7, and 8 speed freewheels. But the widths of 5, 6, 7, and 8 speed freewheels are all different. 5-speeds are roughly 25mm, 6 and 7 speeds are about 31mm and 8 speeds are around 35mm. So if the hub accepts 8 speed freewheels and you are threading on a 7 speed, the freewheel will sit about 4mm inboard of where it would with a hub spaced for a 7 speed freewheel. You could try just adjusting your rear derailer hi/lo stops to match where the freewheel sits on the new wheel. If you can't get the rear derailer to go inboard enough to get to the largest FW cog, you could look into removing some axle spacers from the drive side (but this will require redishing the wheel).