Ronstan RF104100 100mm Core Single Pulley – High-Load Swivel Block

The Ronstan RF104100 100mm Core Single Pulley is engineered for high-performance sailing and racing applications. Featuring a 100mm sheave, it accommodates rope diameters up to 18mm. The block boasts a maximum working load of 3,250kg and a breaking load of 7,500kg, ensuring reliability under extreme conditions. Its universal head allows full 3-axis articulation, which can be locked at 0° or 90° using a 2.5mm hex key. Constructed with durable aluminium alloy cheek plates and a glass fibre reinforced nylon sheave, it offers exceptional strength-to-weight ratio. The ball bearing system minimizes friction and counteracts side thrust loads, enhancing performance and longevity. Ideal for mainsheet, halyard, vang, and spinnaker sheet applications on boats up to 16m (53ft)