The Simplicity rollers are designed to carry (or float) the weight of the deck. If your deck isn't designed to float you would be better off installing an aftermarket brush style striping kit. A brush does just as a good a job as rollers to lay down stripes.
Essentially, anything can be dragged along to bend the grass in one direction will work. If the deck is not full floating, you are better off to float the drag because if the rollers don't put enough pressure at the base of the grass, it won't put a nap in it. A heavy iron bar would do too, doesn't have to roll.