Ronstan RF35140 Series 30 Orbit Single Block with Stand Up Swivel

The Ronstan RF35140 Series 30 Orbit Block is a lightweight, high-performance single block with stand-up swivel designed for modern sailboat rigging systems. With a 30mm sheave diameter, this block is ideal for mainsheets and control line turning blocks mounted low in the cockpit, making it a versatile workhorse for dinghies and larger sailing vessels.

Advanced Two-Stage Bearing System:

Ronstan engineered the Orbit Block series to deliver the highest strength-to-weight ratio in its class. The innovative two-stage bearing system automatically adapts to load conditions: high-compression acetal orbital ball bearings migrate to loaded areas of the sheave for light to moderate loads, while a full-contact PTFE-impregnated nylon bearing with carbon fiber reinforcement handles higher static loads with exceptional efficiency.

Lightweight Composite Construction:

Through extensive computer modeling, Ronstan replaced unnecessary metal components with engineered glass fiber reinforced nylon cheeks and head design without compromising strength. The hollow bearing at the center of the sheave serves as a becket, further reducing weight while adding versatility. The block can be secured using the supplied loop or converted to a soft attachment using a Dyneema link for additional weight savings.

Key Features:

• 30mm UV-resistant acetal sheave compatible with 5/16" (8mm) conventional doublebraid and high-tech 12-strand lines
• Stand-up swivel for optimal alignment in dynamic sailing conditions
• Dual-stage bearing system for smooth operation under varying loads
• Glass fiber reinforced nylon construction for superior strength-to-weight ratio
• Hollow bearing center serves as integrated becket
• Compatible with 5/32" shackle pin diameter
• Highest working loads in its class
• Ideal for dinghy control line systems and yacht applications

The RF35140 delivers professional-grade performance in a compact, lightweight package that excels in both racing and cruising applications.