2025 Ronstan Marine Catalogue - Catalog - Page 42
SPORTS BLOCKS
Series 75 Two-Speed Mainsheet Systems
40
RF70300
3:1
or
6:1
4:1
or
8:1
RF72700B
RF72900B
6:1
RF72330
Two-speed mainsheet systems allow fine tuning of the
mainsheet when sailing upwind by using one of the
sheet tails and keeping the other cleated. Using both
the sheets at once allows the trimmer to blow off the
main quickly when rounding the top mark and trim
on quickly when hardening up after rounding the
bottom mark.
When fitting to traveller cars, ensure adequate
support for the bottom block and use stand-up spring
kit RF324-2. (Refer to traveller section pages 107 &
111 for more information).
PRODUCT No.
DESCRIPTION
Ball Bearing
RF70300
BB triple block, universal head
RF72330
Ratchet triple block, becket, cleat, universal head
RF72700
Complete system, BB & ratchet 3:1 coarse, 6:1 昀椀ne
RF72700B
Ratchet bottom block for RF72700 two-speed system
RF72700T
BB top blocks for RF72700 two-speed system
RF72900
Complete system, BB & ratchet 4:1 coarse, 8:1 昀椀ne
RF72900B
Ratchet bottom block for RF72900 two-speed system
RF72900T
BB top block for RF72900 two-speed system
* Line load through cleat not to exceed 175kg (385lb).
RF72900T
RF72700T
RF72700
RF72900
3:1
or
6:1
4:1
or
8:1
Rope not
included
Two-speed systems: Mainsheets on
sportsboats and keelboats to 12m (40ft).
Ball bearings: acetal.
MAXIMUM MAINSAIL AREA
Cheeks & ratchet sheaves: Anodised aluminium.
RF72700: End boom = 38m2 (409ft2),
Mid-boom = 23m2 (248ft2)
Ratchet pawl: Torlon®.
Sheaves: UV stabilised acetal (BB), alloy (ratchet).
RF72900: End boom = 42m2 (452ft2),
Mid-boom = 27m2 (290ft2)
SHEAVE
DIAM.
mm
MAX.
ROPE
mm
75
75
75 + 50
75 + 50
75 + 50
75 + 50
75 + 50
75 + 50
10
10
10
10
10
10
10
10
PIN
DIAM. M.W.L.
mm
kg
7
7
7
7
7
7
7
7
1250
685*
800
800
800
1100
1100
1100
B.L.
kg
WEIGHT
g
SHEAVE
DIAM.
in.
MAX.
ROPE
in.
2500
2000
1700
1700
1700
2300
2300
2300
632
790
1490
950
560
1610
1035
575
3
3
3+2
3+2
3+2
3+2
3+2
3+2
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
PIN
DIAM. M.W.L.
in.
lb
9/32
9/32
9/32
9/32
9/32
9/32
9/32
9/32
2760
1510*
1760
1760
1760
2430
2430
2430
B.L.
lb
WEIGHT
oz
5510
4410
3750
3750
3750
5070
5070
5070
22.3
27.9
52.5
33.5
19.8
56.8
36.5
20.3
