Antal Low Friction Ring Maximum 5 mm Line R07.05
What are they for? Rings replace blocks. And not just furling lead blocks, but vang cascades, too, backstays, or jib sheet leads. Since their first commercialization, in 2007, under the name of Low Friction Rings, they literally invaded the sailing market. Sailors went low tech gear, choosing simple, non-moving, unbreakable products over standard sheaves.
How much can it hold? A lot. More than needed. Load isn't a problem for Rings, friction however may be. Antal gives a safe working load for Rings that corresponds to a situation where the aluminum structure holds, but undergoes a slight (slight) deformation. So they don't break. Nor do they ever loose their low friction property.
Do we have to worry about friction? This is a good question so let's quickly dig into this. Friction gives higher values on rings than on sheaves, but how much higher? Of course, it depends on two main points: the deflection angle (180° gives higher friction than 90°) and the control system (more rings comes with more friction). It goes without saying it also depends on the Ring quality and the line material.
Focusing on the first two elements (angle and number) allows us to shed some light on the complicated matter of friction. First: Rings are not suitable for all maneuvers. Second: You choose rings in cases where a loss in friction is acceptable in favour of some other benefit; weight, cost, size, durability, or resistance.
Where can Rings go? Though it's not easy to determine how much more convenient it is to use blocks versus rings, there are several cases where sailors have thought that loads allow the use of rings. This also depends on the fact that some systems on sailboats are trimmed less regularly than others. Or maybe they are adjusted before tension kicks in, or maybe the load isn't in fact that high.
Here is a list of possible uses: vang cascades, gennaker tacks, jib sheet leads, lazy jacks, backstays, reefing points and any small deflection angle. (Of course this depends also on the size of the boat! but 70' ocean racing boats use rings.....) So why not use rings then?
Antal R07.05 Low Friction Ring 5mm Technical Spec's
|Ø Line Groove Diameter ||5 mm |
|Ø Hole ||7 mm |
|Weight ||3 gr |
|C ||7 mm |
|SWL ||400 kg |
|Material ||Aluminum |
|T Dimension ||9 mm |
|Outside Diameter ||18 mm |