LAY a damp kitchen towel on the counter. Fill a pie plate with warm water and place beside towel. Dip 1 rice paper round into water and leave until pliable, about 30 sec. Lay softened round on towel. Arrange one-eighth of cucumber along bottom third of round. Layer with avocado, then shrimp, mango, cilantro and peanuts.
LIFT rice paper edge closest to you up and over filling, then roll toward the centre. Fold in sides, then continue rolling to form a log. Set seam-side down on a platter. Repeat with remaining ingredients. Slice rolls in half diagonally.
STIR chili sauce with vinegar in a small bowl until combined. Serve with rolls.