4 discs cable bike lock decoding

[femurat]

I found this cable lock in a public lawn. It was cut and probably the bike was stolen. I saw it sitting there for some days and finally decided to pick it up (pun intended).
First of all I washed it well and removed the other part of the cable. I put it in the vice and used a standard hacksaw, it took me one minute to cut trough it. Made a couple sparks.



I tried the old method of pulling the cable like I was opening it and dialed one disc at a time, looking for some feedback. The first two discs on the left were very hard to turn, the third one was a bit hard and the last one on the right turned free.
Starting from the left, I was looking for a number where the disc was particularly hard to move. Left it there and proceeded with the next one. After a few tries I realized I was going nowhere, because the right most disc was still running free.
So I decided to look for a soft, or free spot. I found one number on the first disc where it was easy to turn, and left it there.
Proceeded with the second disc and did the same.
The third disc finally became hard to turn, and found its place.
Rotated the fourth disc while pulling and... open!



So why not disassemble it? Just remove the strange circlip and I'me done



First numbered disc


First spacer (it's upside down)


Inner part that interlock with the disc and determine the correct number. It's rotated just a little to keep it in place, otherwise the spring on the back would push it out. You can see the small gate close to its protrusion






Same part seen from the other side (upside down)


Another spacer, this time on its correct position: notice the big protrusions in their rails










All the parts as they came out




Here you can see the first disc at its correct position, and the second one is at the false set you get when the small gate is at the large one



And here the first two gates are at the correct position



And here all of the gates are at the correct position, even if you can see only the upmost three





I know these are not very secure locks, but if you find one uncut, it's quite easy to decode it, remove the circlip, reset the combination and use it again.
Now that I dee all the parts laid out, I wonder if it could be enough to rotate the first corrugated part 90 degrees to change the combo. There's a strange part under it that has ramps and the wheelpack is spring loaded... this suggests the possibility to disengage the numbers from their inner parts and change the combo. I'll check this when I get home and let you know if it works.
Seems strange to me that a user needs to remove a circlip to change the combo...

I could trust it to protect my bike front wheel during the day, while my back wheel and frame are locked to a pole with a "real" chain.
One thing that baffled me is that the big dot can be a combination number. I thought it couldn't and I was wrong, in fact one of the numbers of the old combination was the big dot.

Cheers

[femurat]

I confirm that rotating that conical thing 90 degrees clockwise disengages the wheels from the inner parts, allowing me to change the combination. This can be done only when the lock is open. Once the new combo has been set, I can rotate that thing back to its original position and close the lock. The new combo is now set. Simple and clever design.

Cheers

[escher7]

Considering the fact that these locks are low security, this one looks pretty good. The guts look fairly substantial and one minute to hacksaw the cable is decent. Of course they are susceptible to bolt cutters and decoding, but for a non-critical use it would be OK.