A method and device for continuously testing the tensile strength of an optical fiber, wherein the incoming optical fiber is wrapped at least partially around a payout capstan, to an intermediate payout pulley, at least partially around the intermediate payout pulley, and back to the payout capstan. The optical fiber is then wound from the payout capstan to a tensile testing measurement component, and then to an uptake capstan. The optical fiber is wrapped at least partially around the uptake capstan, to an intermediate uptake pulley, at least partially around the intermediate uptake pulley, and back to the uptake capstan. The payout capstan and uptake capstan are operated at a desired rotational speed to continuously advance the optical fiber for tensile strength testing.