Ball Bearing

RF55501

Series 55 Orbit Block™, Fiddle Link Head

Fiddle block with Dyneema® Link Head

FEATURES

Ultra Lightweight

Low friction 2-stage Orbital ball bearing system

Highest working load in its class

Low profile and compact

Easily fitted and securely retained Dyneema® Link head

Specifications

Product Specifications
B.L. (kg)1000
M.W.L. (kg)500
Max. Rope diameter (mm)10
Weight (g)95
Notes:Small fiddle block sheave has a high load full contact bearing (i.e. not ball bearing). Main sheave has 2-stage, ball bearing. Replacement Link: RF9004-08. Replacement Retainer Clip: RF5001

Product Information

Lightweight
Kilogram for kilogram of working load, BB and RT Orbit Blocks™ 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. Multi-sheave blocks have only single intermediate cheeks and an ultra-light and efficient head arrangement. This gives a 30% weight saving advantage over the nearest competitor. Other brands just link together their single blocks. This results in unnecessary double cheeks between each sheave, held together by a heavy steel channel across the top of the block

Highest working load in its class

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 Robline SK75 fibre, which is 10 times stronger and lighter than steel, and provides the final connection from the block to the load point

Fiddle block flexibility

Becket fiddle blocks use a Dyneema® Link attachment for the sheet termination and are suitable for both spliced and un-spliced lines. If you need additional purchase, a becket take-off can be simply added to any fiddle block version just by adding a Dyneema® Link.

Technical Information

Applications

  • Mainsheet systems on dinghies, sportsboats and small keelboats to 9m (30ft)
  • Halyard, Vang and Backstay application on boats to 8m (26ft)
  • Control line applications on larger yachts

 

Materials

  • Ball bearings - High compression strength 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 impregmented SK75 Dyneema®

 

Resource Files

dwg

Need some advice?

Send us a
Message

Find a
Distributor