Do you have a set of calipers? Measure the knot. I'm not sure the reason why knots are set in cups but I do not think you have to have the cup. Maybe someone who knows for sure will correct me if I am wrong. I would say if you don't need the cup and the knot is a 27mm you should be able to order a 28mm handle and it should work. Or buy a smaller handle and open it up wih a dremel. But if the knot is 27mm and you get a handle with a 30mm hole I would think that would be too big of a difference but I can't be positive because I have never tried it.