My motorcycle was sold by my mother while in prison. Bike was in my wife's name. She did not give permissions nor sign the title to anyone. Want bike back. Mother since passed away.
It is your wife's legal issue not yours if the bike was in her name. Your mother has passed away and while your wife might have some financial recourse against her estate, if your mother didn't have anything or what she did have went to you, that would pretty much be a no go.
If you know who has the bike and you go after that person as having bought something fraudulently or for buying stolen goods, then that buyer would then have recourse against your mother's estate, which again, might mean recourse against you if you inherited your mother's estate. (you are not responsible for her debts but if you ended up with assets from her estate those assets could be at risk).
Bottom line...the situation is NOT simple and if you do not know all of the details and take all of the details into consideration you might make a big mess.