Single block 29-40mm stand-up | Master Windrider
Windrider is a series of ball-bearing blocks designed with competitive sailing in mind, but they are also a cost-effective alternative for the cruising sailor. The high-performance composite side plates are designed to ensure optimal performance even under heavy loads. The blocks have high weather resistance, which protects them from failure under all types of sailing conditions and provides long-lasting durability.
Sold individually
AREA OF APPLICATION
The stand-up design allows the block to stand up from the deck, preventing it from hitting the deck when the line is slack. The block is suitable for:
- Mainsail systems, headsails, and spinnakers
- Halyards, vangs, and backstays
- Control lines for boats of all sizes
TECHNICAL SPECIFICATIONS
Material
- Sheave: self-lubricating acetal composite
- Ball bearings: self-lubricating acetal composite
- Side plates/frames: reinforced fiberglass-nylon composite with UV stabilization
- Shackle: Forged stainless steel grade A4/AISI316
Dimensions and loads
| Sheave Ø (mm) | 29 | 40 |
| Max. line Ø (mm) | 8 | 10 |
| Weight (g) | 26 | 43 |
| Working load (kg) | 160 | 230 |
| Breaking load (kg) | 500 | 800 |
FREQUENTLY ASKED QUESTIONS (FAQ)
How do I choose the right block size?
Base your choice on the line diameter and the load the block will carry. 29 mm sheave: line up to 8 mm; 40 mm sheave: line up to 10 mm. The working load should always be higher than the actual load.
What is the difference between working load and breaking load?
The working load is the load the block is intended to handle continuously. The breaking load is the load at which the block will fail and should never be used as a design value.
Does the block need lubrication?
No, the sheave and ball bearings are made of self-lubricating acetal composite. It is recommended to rinse the block with fresh water after use in salt water.