In an aspect, a power transfer device, such as a decoupler, is provided for transferring torque between a shaft and a belt. The device includes: a hub configured to 5 couple to the shaft, a pulley rotatably coupled to the hub that includes a power transmitting surface configured to engage the belt, an isolation spring to transfer a rotational load from one of the pulley and the hub to the other of the pulley and the hub, optionally a one-way clutch to permit overrunning of one of the pulley and the hub relative to the other of the pulley and the hub in a first direction, and a damping member 10 positioned to be driven into frictional engagement with a friction surface by a force from the isolation spring acting on the damping member that varies based on the rotational load transferred by the isolation spring.