Gozzo wrote:No Bicentric locks have two keyways one locks and one unlocks the lock, Im referinf to the Abus 83 series. Here is what I am talking about. for some reason I cant attache an image or I would.
Gozzo.. what you're referring to as double barrel is not a good example.. do you mean the cylinder/core looks like a snowman? Sounds like your Abus has an SFIC core, or it just has a bible sleeve which makes it look like the bottom of the padlock has 2 overlapping circles, one circle has a keyway and one is solid. This is a way of inserting the lock cylinder into the padlock and keeping it in there by means of a set screw which is installed when the shackle is popped open and you can get a screwdriver down the schackle holes.
Btw, Yale Bicentric was a method of master-keying BEFORE they invented master wafers. One cylinder did not unlock the lock and then one cylinder locked it, it was meant so a supervisor, boss, maintenance guy could open all the locks with his key and his keyway, and the users who used the locks, their key could work the other keyway and only open their padlock, not anyone elses.
The thing you describe is like a manager/worker setup where Abloy and other brands had a set of reversed keys where one could turn clockwise and unlock the store in the morning, but the night employee's key could only lock up for the night so they could not come back at 3am and steal something. You can modify normal pin tumbler cylinders by filing the pin chambers wider to do the same function but its a home made job.
Your Abus core either looks like this (which the back of it will have a hole with screw threads to accept a set screw:

or it will look like this assembly: (notice the cap that will go onto the cylinder's bible? that forms the other circle I think you're talking about)

Hope this explains it.. otherwise post the Http:// of your photo, you cannot upload to the forum, the server is full. use [url]http://tinypic.com[url]
Squelchtone