Abstract: An apparatus for proof testing an optical waveguide fiber includes a first capstan defining a first outer diameter and a continuous first capstan belt under tension and in contact with the first outer diameter of the first capstan. The contact between the first capstan belt and the first capstan defining a first arc of contact, and the first capstan belt defining a first width, a first thickness and a first length. The apparatus further includes a second capstan defining a second outer diameter and a continuous second capstan belt under tension and in contact with the outer diameter of the second capstan. The contact between the second capstan belt and the second capstan defining a second arc of contact, second capstan belt defining a second width, second thickness and a second belt length. The first arc of contact being equal to or greater than about 105° and the second arc of contact being at least 20° greater than the first arc of contact.