Repeater mechanism for a timepiece with a striking mechanism, which comprises: - An hour snail; - An hour part bearing an hour feeler-spindle and mounted in rotation about an hour axis between: • A resting position in which the hour feeler-spindle is offset angularly from the hour snail; • A reading position in which the hour feeler-spindle comes in contact with the hour snail; - An hour spring which returns the hour part towards its reading position; - A striking mechanism barrel, which comprises: ∘ A barrel shaft; ∘ A barrel drum, ∘ A barrel spring, an internal end of which is integral with the barrel shaft and an external end of which is integral with the barrel drum; ∘ A pulley; - A chain which is able to be wound up partially on the pulley, the chain being hooked, by a proximal end, on the pulley and, by a distal end, on the hour part; characterised in that the pulley is mobile in rotation relative to the barrel shaft, and the striking mechanism barrel comprises: - A ratchet, integral in rotation with the barrel shaft and: • coupled in rotation with the pulley as long as the hour part exerts a traction force on the chain; • uncoupled in rotation from the pulley as soon as the traction force exerted on the chain by the hour part in the reading position is cancelled out; - A pulley spring interposed between the ratchet and the pulley, and which exerts on the latter a resistant torque which keeps the chain under tension when the ratchet is uncoupled in rotation from the pulley. - An hour snail; - An hour part bearing an hour feeler-spindle and mounted in rotation about an hour axis between: • A resting position in which the hour feeler-spindle is offset angularly from the hour snail; • A reading position in which the hour feeler-spindle comes in contact with the hour snail; • A resting position in which the hour feeler-spindle is offset angularly from the hour snail; • A reading position in which the hour feeler-spindle comes in contact with the hour snail; - An hour spring which returns the hour part towards its reading position; - A striking mechanism barrel, which comprises: ∘ A barrel shaft; ∘ A barrel drum, ∘ A barrel spring, an internal end of which is integral with the barrel shaft and an external end of which is integral with the barrel drum; ∘ A pulley; ∘ A barrel shaft; ∘ A barrel drum, ∘ A barrel spring, an internal end of which is integral with the barrel shaft and an external end of which is integral with the barrel drum; ∘ A pulley; - A chain which is able to be wound up partially on the pulley, the chain being hooked, by a proximal end, on the pulley and, by a distal end, on the hour part; - A ratchet, integral in rotation with the barrel shaft and: • coupled in rotation with the pulley as long as the hour part exerts a traction force on the chain; • uncoupled in rotation from the pulley as soon as the traction force exerted on the chain by the hour part in the reading position is cancelled out; • coupled in rotation with the pulley as long as the hour part exerts a traction force on the chain; • uncoupled in rotation from the pulley as soon as the traction force exerted on the chain by the hour part in the reading position is cancelled out; - A pulley spring interposed between the ratchet and the pulley, and which exerts on the latter a resistant torque which keeps the chain under tension when the ratchet is uncoupled in rotation from the pulley.