Rick Rybicki

Hi all, I'm new to this site but need some advice. I'm a long term Virago rider but am rebuilding an old BSA that I've had for over 30 yrs. I'm putting a 125 Dragstar fromt end on it and am having a 21" rim built on to the hub. I didn't check the wheel for off-set before I took it apart. Actually it wasn't straight enough to check! Can anyone tell me if a Dragstar 125 front wheel is off-set or central. If it is off-set, how much and which side. Thanks, Rick.