Ronstan RF55521 Series 55 Ball Bearing Orbit Block – Fiddle & Cleat Link Head

Highest working load in its class

Kilogram for kilogram of working load, the Ronstan RF55521
Series 55 Ball Bearing Orbit Block – Fiddle & Cleat Link
Head is among Ronstan’s BB and RT Orbit Blocks that are
the world’s lightest. The unique orbital design allows the bearing
to only be in the active areas of the floating sheave. This
minimises the mass of the inactive return race and hub. Weight and
bulk are further reduced in the different block configurations. The
ball bearing single and becket block has a through-sheave becket
arrangement. The result? The lowest weight possible.

Ronstan RF55521 Series 55 Ball Bearing Orbit Block – Fiddle
& Cleat Link Head Features:

• Multi-sheave blocks have only single intermediate cheeks and an
  ultra-light and efficient head arrangement.
• The orbital ball-bearing arrangement gives the largest possible
  bearing race diameter. This maximises load performance.
• The proven Ronstan 2-stage bearing system features high
  compression grade acetal ball bearings and a secondary full-contact
  bearing. This gives minimum friction across the full working load
  range
• The floating sheave and bearing system is supported by a
  fibre-reinforced load frame. The design was computer modelled to be
  stress optimised
• The Dyneema Link is produced from FSE Robline SK75 fibre, which
  is 10 times stronger and lighter than steel, and provides the final
  connection from the block to the load point
• The race-proven carbon-fibre reinforced Ronstan C-Cleat give
  secure rope holding with low entry and exit efforts, and are fitted
  with fairleads for fast action from any angle
• Applications:
  • Mainsheet systems on dinghies, sportsboats and small keelboats
    to 9m (30ft)
  • Spinnaker sheets on dinghies, sportsboats and small keel boats
    to 9m (30ft)
  • Halyard, Vang and Backstay application on boats to 8m
    (26ft)
  • Control line applications on larger yachts

Ronstan RF55521 Series 55 Ball Bearing Orbit Block – Fiddle
& Cleat Link Head Specifications:

• Sheave diameter: 55 + 35 mm
• Max. Rope diameter: 10 mm
• M.W.L.: 500 kg
• B. L.: 1000 kg
• Weight: 231 g
• Materials:
  • Ball Bearings – High compression stregnth carbon black
    Acetal
  • Stage 2 bearing – Carbon fibre reinforced, PTFE impregnated
    Nylon
  • Frame/Cheeks – Toughened, glass fibre reinforced Nylon
  • Rope/Link – UV stabilised, multi-strand impregnated SK75
    Dyneema