Ronstan Orbit blocks are Ronstan's high-performance block range, built around a two-stage bearing system and fibre-reinforced sheaves that deliver an exceptional strength-to-weight ratio. In practice this means they run with very low friction under light loads yet carry heavy loads without failing, which is why they are found on everything from dinghies to offshore racing yachts.
Ronstan Orbit blocks at a glance
| Feature | What it does | Why it matters |
|---|---|---|
| Two-stage bearing system | Ball bearings under light load, full-contact bearing under high load | Efficient across a wide load range in a single block |
| Fibre-reinforced sheave | Composite polymer sheave with low-friction bearing surface | Keeps friction low and resists marine loads and UV |
| Composite + stainless construction | Advanced composite body with stainless steel components | High strength-to-weight ratio for reduced weight aloft and on deck |
| Configurations | Single, double, triple; becket, swivel, snap shackle, stand-up, cheek | Build the exact purchase and lead your system needs |
What makes Ronstan Orbit blocks different?
The standout feature of Orbit blocks is their strength-to-weight ratio. Ronstan combines advanced composite materials with stainless steel components to build blocks that are both very strong and light, which matters in high-performance sailing where weight aloft and on deck affects speed and handling. The sheave is a fibre-reinforced polymer that keeps friction low and efficiency high while resisting the loads and UV exposure of a marine environment.
How does the two-stage bearing system work?
Orbit blocks use a two-stage bearing system that combines ball bearings for low loads with a full-contact bearing surface for high loads. Under light load the balls roll freely for minimal friction and effortless trimming; as load increases, the full-contact bearing takes over to carry the force without crushing the bearings. The result is a block that performs efficiently across a much wider load range than a single-bearing design: precise trimming when it is light, reliable strength when it is loaded up.
What configurations do Orbit blocks come in?
Orbit blocks come in a range of sizes and configurations: single, double and triple, with beckets, swivel heads, snap shackles, cheek mounts and stand-up springs, so you can build the exact lead you need. This makes them suitable across the boat: mainsheet systems, vang and outhaul purchases, spinnaker gear and control lines.
How do I choose the right Orbit block?
Selecting an Orbit block follows the same logic as any block, with performance in mind:
- Load: pick a size whose working load exceeds your peak line load with margin for shock loads.
- Line diameter: match the sheave to your line size for smooth running and minimal wear.
- Configuration: single, double or triple and head type (fixed, swivel, becket, snap shackle) to build your purchase and lead.
- Application: choose Orbit where low weight and low friction matter most, such as racing and performance-cruising systems.
Frequently asked questions
What is special about Ronstan Orbit block technology?
Orbit blocks use a two-stage bearing system, ball bearings for low loads and a full-contact bearing for high loads, combined with fibre-reinforced sheaves and composite/stainless construction. This gives a high strength-to-weight ratio and low friction across a wide load range.
How does the two-stage bearing system work?
Under light load the ball bearings roll freely for minimal friction and easy trimming. As load increases, a full-contact bearing surface takes over to carry the force without crushing the balls, so one block performs efficiently across a much wider load range than a single-bearing design.
Are Ronstan Orbit blocks suitable for cruising boats?
Yes. While Orbit blocks are engineered for high-performance and racing use, their durability and low friction also benefit cruising boats, especially on frequently adjusted systems like the mainsheet and vang. For light-load, set-and-leave leads, a standard block may be more economical.
What configurations do Ronstan Orbit blocks come in?
Orbit blocks are available as single, double and triple blocks, with options including beckets, swivel heads, snap shackles, cheek mounts and stand-up springs. This range lets you build exact purchases and leads for mainsheet, vang, outhaul, spinnaker and control-line systems.
How do I choose the right size Orbit block?
Match the block to your peak line load with margin for shock loads, and match the sheave to your line diameter. Then choose the configuration and head type that builds the purchase and lead you need, favoring Orbit where low weight and low friction matter most.
Shop all Ronstan Orbit Blocks →