After modelling a tread of a tire and applying an array modifier, Image "e" shows that the modelled tread needs a little bending to to make a everything line up as it should. Tried simple deform modifier with different origins, settings and curves, but could not get it as I need it.
Problem solved. Used a circle as a target for the aray of treads with the array modifier. That worked but did not bend the tread mesh itself. Using a nurbs curve and a curve modifier also bended de mesh of the tread.