Excelsior

i buy from other player a leg giving +5 lockpik .

after used it some he goes out and discovert he got

stat
durability
lockpik +
tenacity

and the tenacity goes to 0/255 ..

i try repair it blacksmith , tailor but nothing put tenacity up . i can't wear it anymore and find nobody who can inform me about that ...

As you use +lock picking, and +cartography gear its tenacity goes down.

This is on purpose, so eventually the piece becomes useless. There is no way (currently or planned) to repair it.
It is meant as a way to help keep the items valuable over time, as pieces eventually don't provide a bonus any longer, and you either need to buy, or find a new piece.

ok , that i learn never buy that item anymore they are exepensive for so less using time

Has the wiki page been upgraded to include the new modifications to lock picking (new maps and gear)? I could not find it, but then again I just did a simple and quick search.