28
DN World Championship © Harken
2633
2682 
2626
2681 
2628
2684 
2627
2683
2625
2680 
2625.
RED
2626.
RED
 
 
 
 
 
 
 
 
 
 
Ratchamatic Blocks
The Carbo Ratchamatic is a load-sensing ratchet block 
that rolls freely in both directions under low loads and 
automatically engages the ratchet as loads increase. 
Shifting between ratchet and light-air modes is seamless.
 Unloaded main and jib sheets run out freely during 
mark roundings and asymmetrical spinnakers free 
instantly during jibes. 
Ratchet engagement may be adjusted to a higher or lower load 
according to strength and sailing style. The Ratchamatic cheek 
block mounts on either port or starboard. The holding power 
of the 57 mm is as high as 10:1. The 75 mm is up to 15:1.
For the ultimate system, mount a Ratchamatic block on 
the boom above a cockpit-mounted switchable ratchet to 
allow the mainsheet to run freely in light air and to double 
holding power in heavy air.
Use the 2634 with a 402 or 403 swivel arm for a versatile 
two-speed mainsheet system.
About Carbo Air blocks: see feature page at beginning of this section.
Adjustable ratchet engagement adapts 
block to a variety of applications.
*Includes RH fasteners and mounting pad.    **Maximum working loads and breaking loads for blocks based on cam strengths.
Eight-faceted, Hard Lube-anodized
aluminum sheave holds line securely.
Part No.
Description
Sheave
Ø
Length
Weight
Shackle pin
Ø
Max line
Ø
Maximum
working load
Breaking
load
Holding power 
w/180° wrap
in
mm
in
mm
oz
g
in
mm
in
mm
lb
kg
lb
kg
50 lb (23 kg)
 57 mm 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 2625 / .RED  Single 
 2 1/4 
 57 
 4 1/16 
 103 
 3.7 
 104 
 3/16 
 5 
 3/8 
 10 
 500 
 227 
 2000 
 907 
 10:1 
 2626 / .RED  Single/becket 
 2 1/4 
 57 
 4 15/16  125 
 4 
 113 
 3/16 
 5 
 3/8 
 10 
 500 
 227 
 2000 
 907 
 10:1 
 2627 
 Single/150 Cam-Matic** 
 2 1/4 
 57 
 4 1/16 
 103 
 9.4 
 266 
 3/16 
 5 
 3/8 
 10 
 300 
 136 
 750 
 340 
 10:1 
 2628 
 Single/150 Cam-Matic/becket** 
 2 1/4 
 57 
 4 15/16  125 
 9.7 
 275 
 3/16 
 5 
 3/8 
 10 
 600 
 272 
 1500 
 680 
 10:1 
 2633 
 Cheek* 
 2 1/4 
 57 
 3 1/4 
 83 
 3.1 
 89 
 
 
 3/8 
 10 
 500 
 227 
 2000 
 907 
 10:1 
 75 mm 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 2680 
 Single 
 2 15/16 
 75 
 5 3/8 
 137 
 8.4 
 238 
 1/4 
 6 
 7/16 
 12 
 750 
 341 
 3000 
 1361 
 15:1 
 2681 
 Single/becket 
 2 15/16 
 75 
 6 1/2 
 165 
 9 
 255 
 1/4 
 6 
 7/16 
 12 
 750 
 341 
 3000 
 1361 
 15:1 
 2682 
 Cheek* 
 2 15/16 
 75 
 4 1/16 
 103 
 6.5 
 184 
 
 
 7/16 
 12 
 750 
 341 
 3000 
 1361 
 15:1 
 2683 
 Single/150 Cam-Matic** 
 2 15/16 
 75 
 5 7/16 
 138 
 15.5 
 440 
 1/4 
 6 
 7/16 
 12 
 300 
 136 
 750 
 340 
 15:1 
 2684 
 Single/150 Cam-Matic/becket** 
 2 15/16 
 75 
 6 1/2 
 165 
 15.5 
 440 
 1/4 
 6 
 7/16 
 12 
 600 
 272 
 1500 
 680 
 15:1 
Ratchet or
Ratchamatic?
All 57 mm and 75 mm Ratchamatic 
blocks are also available with Power3 
sheaves which offer holding power 
options suitable for a variety of wind 
conditions. In addition, all 57 mm 
Ratchamatic blocks can be made with 
HTE (high threshold engage) sheaves 
to delay ratchet engagement, allowing 
them to run freely more of the time. 

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