How do lock Cylinders on Sport Panniers Get Rekeyed?

[robortiz59]

I just bought a set of used panniers and they are being sent to me. They are currently keyed to match the bike they came from. The person who sold them to me is sending them unlocked. But, understandably, he doesn't want to send his spare key. So how do these actually get rekeyed? Do I need to buy new cylinders? Can the existing cylinders be somehow changed to match my key? Or is there some other way of setting them up to match my existing key?

[Flynt]

Local dealer re-keyed mine when I moved them from the old K12 to the new K13S... It can be done and it took some time, but I didn't watch to see how difficult it might be (thrown in as a condition of sale for the K13).

Frank

[WFBRoddy]

See >>HEREhttp://www.bmwmotorsports.org/k12s/locks/locks.html<<

Its futtery to do but take your time, I believe new leafs can be bought from the dealer if needed

[robortiz59]

I'm not sure what futtery is. But I followed these instructions and removing the cylinder was no problem at all. Nine screws and you push a tab with a small pick and it slides right out. It took maybe 10 minutes.

So after I have the cylinder on the bench I get ready to actually make the changes to (rekey) it. Basically, the cylinder has six wafers - or pins - in it. Those wafers ride up and down in the notches in the key when it gets inserted. Each wafer has a different dimension. When the key is removed, or the incorrect key inserted, the wafers protrude beyond the edge of the lock cylinder and this is what prevents it from turning. When the cylinder is configured correctly all the wafers will be flush with the cylinder casing when the key is inserted. This allows the cylinder to turn in the mechanism.

Anyway, the idea is you slide your key in and see where the wafers stick up. You then shuffle the wafers around until you find the combination that ends up with all of them being flush with the cylinder casing. (See the attached picture.) Its, basically, a big puzzle.

So I slide my key in for the first time to see what I need to change. And damned if all the wafers aren't flush. This can't be, I say. I had not even tried my key in the lock. I just assumed it would need to be rekeyed. So I insert the key in the other bag, which I had not yet disassembled, and it worked perfectly. My key fit the lock on the used bags perfectly! I didnt have to change a thing. I reassembled the locking mechanism, and everything works perfectly.

What are the odds that my key would fit this lock? Well, if I remember my probability mathematics correctly, its 1 in 729. There are only three different variants of the wafers. There are six wafers in the cylinder. That means there are three to the sixth power possible combinations of arrangements, which equals 729. Said another way, there are 729 possible keys to fit the cylinder. I found this a little surprising. It means that if you slid your key into my lock there would be only a 1 in 729 that your key would fit my lock.

Thanks to WFBRoddy for the information.