I just picked up a 1999 x1 lightning and a chain conversion was already done . It had a new Vertox back sprocket installed and it´s chewing one side of it, along with busting teeth off . Just by looking at it the spockets don´t line up . I seen they have those off-set sprockets for the front but seems they are off-set the wrong way . Do they make an off-set for the back or is there spacers I need to put of the back rim ? IDK any help would be helpful , don´t want to waste money on a new back sprocket if I can fix the problem . Thanks