Ronstan Series 55 Ball Bearing Triple Ratchet Orbit Block™ - Becket, Cam Cleat
Ronstan Series 55 Ball Bearing Triple Orbit Block™ with Becket
The Ronstan Series 55 Triple Orbit Block™ with Becket is designed as the lower block in high-efficiency mainsheet systems, delivering smooth running performance and excellent load handling in compact multi-purchase setups.
Built around Ronstan’s ultra-lightweight Orbit Block™ architecture, this triple block combines low friction operation with high strength. The 2-stage orbital bearing system ensures minimal resistance across the full load range, maintaining responsiveness in light winds while handling high sheet loads with ease.
The integrated becket allows for clean anchoring of the system and provides the attachment point for a cascade block, enabling higher purchase ratios without increasing overall system size.
Key Features
- Triple sheave configuration for mainsheet systems
- Integrated becket for system anchoring and cascade attachment
- Low friction 2-stage orbital ball bearing system
- Lightweight, compact Orbit Block™ design
- High strength fibre-reinforced construction
- Swivel head for unrestricted articulation
Key Specifications
- Sheave diameter: 55mm
- Maximum rope diameter: 10mm
- Breaking load: 1500kg
- Safe working load: 750kg
Applications & System Integration
The RF56330B is designed to function as the lower block in compact cascading mainsheet systems, working directly with the RF55410 quad upper block.
In a standard 8:1 mainsheet system, the configuration is:
- Upper block: RF55410 – Series 55 Quad Orbit Block™ with Becket
- Lower block: RF56330B – Series 55 Triple Orbit Block™ with Becket (this product)
- Cascade block: RF48109 – Orbit 40 Single Block, attached to the lower block becket
This setup delivers a compact and efficient 8:1 purchase, ideal for dinghies and small catamarans where smooth trimming and weight reduction are key.
For increased power, the system can be upgraded to a 9:1 configuration:
- Upper block: RF55410
- Lower block: RF56330B
- Cascade block: RF48209 – Orbit 40 Double Block (replacing RF48109)
This increases mechanical advantage while maintaining excellent rope flow and load distribution.
The RF56330B plays a key role in both systems:
- Providing the working base for the mainsheet
- Acting as the cascade anchor point via its becket
- Ensuring smooth, controlled sheeting under load
Specifications
| Ropes | |
|---|---|
| Recommended line - Max Ø (mm) | 10 |
| Boat | |
|---|---|
| Recommended Boat size - Max (ft) | 30 |
| Load | |
|---|---|
| SWL (kg) | 250 |
| NBL (kg) | 650 |
| Blocks | |
|---|---|
| Bearing type | Ball bearing |
| Ratchet | Yes |
| Dimensions | |
|---|---|
| Sheave Ø (mm) | 55 |
| Furling |
|---|
| Compatibility |
|---|
| Weight | |
|---|---|
| Weight (g) | 392 |
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