zero preload spring

[Limited Z_400]

Does the adjuster nuts on the rear shock change the ride height only if it has a zero preload dual spring set up?

[NacsMXer]

Yes they change the ride height only. But if you crank down the nuts too far it will completely collapse the ZPS spring. That will start putting pressure on the main shock spring and start to add "preload". If you did that, there wouldn't be much point in having a ZPS shock.