Ronstan RF75111 Series 70 Ball Bearing Orbit Block – Single & Becket Link Head

Lightweight

Kilogram for kilogram of working load, BB and RT Orbit Blocks
are the world’s lightest. To gain peak performance, we engineered
out the heavy steel load straps, head post, shackle, full-length
fasteners, and cleating accessories. Through extensive research and
development, we replaced virtually all metal components with
high-tech polymers and fibre equivalents.

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 with becket and double with
becket blocks have a through-sheave becket arrangement. The result?
The lowest weight possible.

Double blocks also have only a single intermediate cheek 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 and
optimised using stress analysis. 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.

  

Simple and secure attachment

The Dyneema Link is easily fitted and is retained securely by a
moulded retainer clip. The flexible link can be left with one end
attached to the block when fitting – no more lost shackle pins.

The system is compatible with Dyneema/Spectra strops, webbing
and carbon connection points – much more so than steel loop tops or
shackles.

Low profile and compact

The flexible Dyneema Link provides controlled rotation and 0
degrees or 90 degrees orientation. It connects directly to the head
of the block rather than to an intermediate head post. This reduces
weight and gives the lowest possible profile while allowing full
articulation. Beckets have been carefully designed to minimise
height.

Low profile stand-up kit allows 0 degrees
or 90 degrees alignment

The RF2457 stand-up kit features a clatter-free rubber boot. You
can attach the  Dyneema link so that the block is aligned with
the stand-up base or across it. It’s a neat, low-profile solution
which allows full articulation.

Applications

• Mainsheet systems and spinnaker sheets on sportsboats and small
  keelboats to 11m (36ft)
• Halyard, Vang and Backstay application on boats to 9m
  (30ft)
• 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

Spare Parts

Product No.	Description
RF70001	BB and RT Orbit Block Accessories, , Retainer clip, S70 BB and RT single Orbit Blocks,
RF9005-10	BB and RT Orbit Block Accessories, , Dyneema link, S55 BB and RT double and triple Orbit Blocks, S70 BB and RT single Orbit Blocks, diameter5mm x ID 100mm,

Features:

• Ultra Lightweight
• Low friction 2-stage Orbital ball bearing system
• Highest working load in its class
• Easily fitted and securely retained Dyneema Link head
• Ultra low profile, thru-sheave becket

Specifications:

Sheave diameter	70 mm
Max. Rope diameter	12 mm
Max. Cable diameter	– mm
Pin diameter	– mm
M.W.L.	700 kg
B. L.	1400 kg
Weight	141 g