More Information
Selden low friction rings are an extremely versatile and lighter alternative to a plain bearing block.
Selden rings are produced in black anodised aluminium, have a big inner radius for low friction and an outer slot for rope or shock cord attachment to e.g. a deck or mast fitting
Suitable applications are backstay cascades, barber haulers, tweakers, kicker/vang purchases or any other control line lead with a static load.
Low friction rings are not designed to replace ball bearing or roller bearing blocks where free running or continuous adjustment under load are required.
Selden | Internal Ø | Maximum Line Ø | SWL | MBL | Outside Ø |
---|---|---|---|---|---|
420-500 | 5mm | 3mm | 150kg | 300kg | 12mm |
420-501 | 8mm | 5mm | 350kg | 700kg | 18mm |
420-502 | 11mm | 7mm | 750kg | 1500kg | 25mm |
420-503 | 16mm | 10mm | 1500kg | 3000kg | 35mm |
420-504 | 22mm | 14mm | 3000kg | 6000kg | 50mm |
420-505 | 30mm | 20mm | 6000kg | 12000kg | 70mm |
Internal Ø = the internal diameter of the hole inside the ring
Maximum Line Ø = the maximum diameter line that Selden recommend to use through the ring
SWL = Selden Safe Working Load (2:1 Safety Factor)
MBL = Manufacturer (Selden) Break Load
N.B. Outside Ø is actually the outside width dimension across the ring
Barber Hauling or Tweaking is a good example of where low friction rings provide an ideal solution:
Barber Hauling, also known as "Tweaking" is the general term for applying downward pressure on a headsail sheet and/or pulling the clew to windward to improve the slot and increase leech tension.
Reeeve the ring onto the sheet, attaching the tweaker line to a strongpoint, suitably poisitioned inboard and aft of the mast step, one on either side of the deck to create a 2:1 purchase on the sheet.
Improved sail trim can then be achieved by tensioning the tweaker.
Stretch a bungee (elastic cord) from the ring to a shroud high enough to prevent the ring knocking the deck when it is not in use (lazy).