A slide drive device for a press changes a slide stroke without a changing either a top or bottom dead center position of a slide. The slide drive device allows stroke adjustment without a loss of left-right balance in the slide drive device. An adjusting mechanism is driven by an eccentric part and a crank shaft. The adjusting mechanism is adaptable to fix either the top or bottom dead center position. A linear guide mechanism, is driven by the adjusting mechanism, and transfers adjustments in slope angle into changes in stroke relative to either the top or bottom dead center position without requiring a change in the dead center position. Alternate embodiments allow positioning and adjustment for convenience and economy.