Mainsheet Tackle Bench Test

Whats the best 4:1 mainsheet control system?


Stroll through your local marina, and you’ll likely see plenty of resurrected, vintage sailboats, sporting newly painted hulls and decks, and replaced sails and rigging. But all too often, antique mainsheet blocks have somehow escaped the upgrade. Part of the reason for this oversight is that the sheaves, ensconced between weathered cheekplates, get only an occasional, no-load test spin, and all but the most severely deteriorated pass the scrutiny. Theres also an If it ain’t broke, don’t fix it mindset that usually makes sense, but in this case, a relatively simple and cost-effective block swap can greatly improve mainsail handling.

Mainsheet tackle comprises blocks, shackles, swivels, and a wide array of attachment hardware that allows us to more efficiently trim and shape the mainsail. Some sailors seek mainsheet simplicity, while others want sheet-hauling speed and fine-tune control. Arguably, the mainsheet tops the list of sail-trim controls, allowing a crew to adjust the boom angle in reference to the boats centerline and respond to changes in apparent-wind angle. It also can influence the downward force that alters the leech twist of the mainsail. In short, the mainsheet and the jib sheet are the key players when it comes to efficiency under sail.

What We Tested

In this round of mainsheet tackle testing, we sought products that makers would recommend for a Pearson 30. We narrowed the field to eight systems, all sized for small to mid-size cruiser-racers and daysailers (20 to 30 feet) that employ the mechanical advantage of a 4-to-1 mainsheet tackle. The test field included products from Antal Marine Equipment, Garhauer Marine Hardware, Harken, Nautos, Ronstan, Schaefer Marine, and Seldn Mast-all well-known makers of deck hardware.

All of the tested tackle featured a pair of fiddle blocks (one with a becket and a cam cleat), and all came with shackle ends that could be locked or allowed to swivel. Except for the Seldn, all of the systems used ball or roller bearings, and all have alloy, stainless steel, or injection-molded plastic cheekplates or cage frames. All of the sheaves-except those in the Garhauer products and the Harken and Nautos ratchet blocks-were non metallic. Glass fiber, Acetal, Delrin, and other plastic composites have become a favored alternative to metal sheaves.

Each companys engineers develop their own fiddle-block geometry and settle on a diameter ratio between the smaller and larger sheaves. This influences line leads and clearance. Among the test products, cam cleat design showed a wide range of differing thought, and in some cases, the cam-cleat structure was the limiting variable in setting a safe working load for the fiddle block/cam cleat combo.

How We Tested

The classic 4-to-1 mainsheet tackle comprises two fiddle blocks; one is simply a pair of inline sheaves, but the deck-level block includes a becket and a cam cleat. Ideally, this simple machine makes hauling in the mainsail four times easier when it comes to line-pull effort. For example, if a single line were attached to the boom and it required a 100-pound pull to move the boom inboard, a 4-to-1 purchase would allow you to get the same job done with only 25 pounds of pull. The no-free-lunch rule does come into play, resulting in the need to haul in four times the length of rope in order to cut the load to 25 percent of what it was originally.

All of the above assumes a utopian world of zero friction, so one of our tests sought to determine how well the blocks kept friction at bay. In order to test block efficiency, we set up a carefully controlled load-lifting experiment. It mimicked normal sailing conditions, measuring efficiency in a range well under the safe working load limits of all of the hardware tested.

To accomplish this, we mounted a fixed weight on a vertical rail and used each of the eight tackles to hoist the load. Tension in pounds, smoothness of pull, and cam-cleat operation were recorded. Testers also set up a high-load-strain test jig to evaluate cam operation at a 200-pound load after an 800-pound momentary load had been imposed. The test mimicked a gust and faux knockdown, and measured how easily a mainsheet could be released.

Because all of the test systems were equipped with cam cleats that are intended to be traveler mounted or mounted on a fixed part of the deck, we added a cleating/uncleating test. We also scrutinized the blocks construction materials, and noted where problems could arise. Factors such as potential for galvanic corrosion, sheave and bearing exposure to UV irradiation, and a wide range of physical design characteristics were considered.


Antals 70 series fiddle blocks are made from a single piece of carefully machined and anodized aluminum. Both the upper fiddle block and the deck-level block are equipped with a unique swivel-head lock that allows the mainsheet tackle to be permanently aligned or to swivel. The composite bushing rides on a stainless-steel hub, and side race ball bearings lessen sheave friction. Testers found that the sheave leads are fair, and theres no sign of line-to-line chafe when an eye splice is used instead of a bowline. Testers liked the precise grip and release of the cam jaws.

The Antal system did not top the scale in any one area, but it did run in the front of the pack. Testers gave high marks to the smooth pull and elegant design of the anti-swivel fitting. One of the more significant features is the cams combination of easy clip and release, powerful grip, and a superior ability to be released under load.

Priced at $563, the Antal system was the most expensive one tested, but it also is rated with the highest safe working load (SWL): 2,860 pounds.

Bottom line: The Antal fiddle blocks are well-engineered and exactingly constructed, but priced at the top of the heap. For those with deep pockets, the OPF70 is our Recommendation for all-around, long-lasting mainsheet control.


Garhauer offers three options as ready-to-connect mainsheet tackle. Each Series 30 combo has a fiddle block and a block with a becket plus a cam cleat that comes rigged with 40 feet of half-inch braided sheet attached via an eye splice. These setups come with either anodized aluminum cheekplates or highly polished stainless steel. And at $115 for the former and $125 for the latter-both with 10-year warranties-they represent a very good buy.

Mainsheet Tackle Bench Test
Left to right: Ronstan; Antal

Garhauers large-diameter ball bearing race fiddle blocks paid off in the pull-efficiency testing, topping out with the low score of 24 pounds. We tested all three Garhauer units, but we reported only on two because the only difference between the alloy-sided blocks was the color of the anodizing. Common dimensions and bearing design among all three resulted in near identical friction test scores. Its interesting to note that using a lower ratio between the big block and small block may have lessened small sheave friction, but it also caused the line running through the blocks to touch, raising concerns about long-term chafe.

Garhauers smooth, efficient cam cleat is welded in place, making it impossible to alter lead angles yourself. However, if the factory lead angle doesn’t work, Garhauer will change it to a custom angle, at no charge.

The screw shackles have shallow threads, but the pins are bored to accept a ring pin. The cam cleat exerts a bear trap-like grip on the sheet (32 pounds of release pull) when a 200-pound load was placed on the tackle. At 800 pounds of tension, it took 45 pounds of pull to free the line.

Bottom line: This is an efficient, ruggedly built set of fiddle blocks and the price is compelling. They get the PS Budget Buy.


Harkens 75-millimeter Carbo Fiddle blocks incorporate cheekplates made of glass fiber-filled nylon resin; they are UV stable and more immune to corrosion than metal alternatives. Harkens switchable ratchet control and easy grip cam cleat make it a user-friendly tackle for mainsheet sheeting. Its patented three-way cam lock adds versatility, and the high-load bearing races ensure smooth operation at the upper end of the safe working load.

Testers also liked the Harkens details, including shorter length, forged stainless-steel D-shackles and the nicely machined aluminum primary sheave in the ratchet block.

Harken has come up with another elegant fiddle block combo. Its strong but light, the cam has a very positive grab, and its versatile in fixed or swivel mode. In fact, testers were a little concerned about the cams alligator-like grip and the higher load release (28 pounds pull) necessary at 200 pounds of tension. We worried about load jamming under higher loads, but after testing at 800 pounds, we were pleased to discover that the release required only saw a small uptick to 32 pounds of pull. The Harken has a SWL of 1,212 pounds.

This Carbo fiddle block couplet also has a ratcheting feature favored by one-design and smaller racer/cruiser owners. The feature can be clutched in or out on the fly, and the only downside is the flat facets on the large sheave of the lower fiddle block-a feature that gives a slight thump-thump feel when hauling the mainsheet.

Bottom line: The Harken Carbo 75 ratchet mainsail systems is priced in the middle of the pack ($280), and its our Recommendation for the serious sailor.


Nautos delivers a well-made, double fiddle-block combo, with a ratcheting feature. The blocks were the smallest in the test field, and not surprisingly, they also had the lowest safe working load. Despite their petite size, the Nautos blocks held their own with bigger blocks, especially when it came to releasing under load.

The fiddle blocks have stainless-steel cheekplates and a cross-riveted construction that holds the bearing surface and sheaves in place. The cam angle is adjustable, but the cam causes the safe working load to be lower than that of the blocks alone (660 pounds versus 880 pounds). These compact blocks also offer a ratcheting feature that can be toggled on or off with the push of a small lever.

Mainsheet Tackle Bench Test

Priced right at $137, the blocks would be well-suited for smaller boats with less mainsail area.

Bottom line: The Nautos blocks are a worthy choice for smaller boats in this size category.


Ronstan Series 60 Core fiddle blocks have a rugged two-stage bearing system that helps them cope with the heavy loads that can deform a primary bearing race. The adjustable-cam fiddle block incorporates a fixed or swiveling head, and the design uses alloy cheekplates to spread tensile loads. The Acetal sheave is UV stabilized, and the shackle post and hub are 316 stainless steel.

The Series 60 fiddle block design eliminates the need for a becket extension as the lower block spindle hole acts as a becket. We found the large-diameter hole on the lower sheave to be a functional alternative that worked well with a simple bowline. It did not chafe on any of the running parts of the sheet, but if an eye splice was to be used, it had to be made up with the block in the loop. It was the only unit tested without a traditional becket.

Friction was higher in this fiddle block combo, but the pull was smooth and even. The cam cleat had an easy-to-engage feel and behaved well under high-load testing. It was interesting to note that although low-load friction was high, the blocks secondary bearing race design improved its high-load operation.

Bottom line: Priced at $318, Ronstan delivers a good 4-to-1 sheeting system. The becketless design got mixed reviews from testers. Simply tying in a bowline works, but an eye splice must be made with the block included in the formation of the loop.


Schaefer fiddle blocks have evolved over the decades, but retain a commitment to functional stainless-steel strapping and anodized-alloy sideplate design. Today, bearings lower sheave friction and an easy-to-adjust cam bracket affords a wide range of lead angles.

The Schaefer Series 5 blocks have a familiar look and appeal, and yet their function has improved. With the addition of ball-bearing races to the Delrin sheaves, the blocks are very smooth running, no matter the load. Overall, quality of construction is very good and cheekplate strength and durability remains a Schaefer signature.

The split ring and strap type shackles are compact and strong, but most testers preferred the more conventional D-type, forged shackles with threaded clevis pins.

At 1,500 pounds safe working load, the Series 5 blocks fall on the lower end of the test field spectrum, and they proved to have less friction than others. Releasing the line from the grippy cam, loaded to 200 pounds, required 30 pounds of pull-about the same required by the Garhauer blocks.

Bottom line: The Series 5 fiddle blocks are compact and make an easy one-for-one upgrade aboard boats with older, similar sized Schaefer mainsheet tackles.


Seldens PBB 60 fiddle blocks are a sensible combination of stainless-steel framework and glass fiber-reinforced cheekplates. The combo becket and cam fiddle block is compact and ergonomic in design. The system also utilizes Acetal sheaves and a Teflon bushing-type plain bearing rather than the roller or ball bearings used in the other tackles we tested. Composite sheaves and a clever push-to-lock swivel immobilizer make Seldens blocks both efficient and cost effective.

Mainsheet Tackle Bench Test

Seldens bushing-type bearings held their own in the normal working load test, with a friction measure of 28 pounds, well inside the range of ball- and roller-bearing equipped competitors (24 to 33 pounds).

These well-designed and constructed fiddle blocks delivered smooth cam operation, and the easy to adjust angle feature is useful. Testers found that cam release under higher loads took more of a yank; whether this was due to cam jaw design or a bearing inefficiency at higher loads could not be determined.

Bottom line: In the normal operating range, the $138 system behaved well, and its compact size and quality construction were big pluses.


Todays sailboat hardware deserves the label better than ever, and all of the mainsheet tackles we tested were an improvement over their predecessors. Extraneous weight and material have been removed, and the safe working load-to-weight ratio increased. Injection molded cheekplates and plastic sheaves are better UV stabilized. Anodized aluminum is isolated from stainless-steel strapping, and CAD design, along with lots of in-house R&D, have led to more user-friendly cam cleats.

All this scrutiny led us to the conclusion that we had an array of very good products rather than a lineup of winners and losers. Those that nosed out the rest tended to be best suited for specific boat niches. For example, if youre a serious racer and have a mainsheet trimmer with a sheet continuously in hand, its hard to beat Harkens take-the-load-off ratchet system. These big, but light 75-millimeter fiddle blocks come with an adjustable angle cam and flip switch ratchet engagement. If theres a weekend cruise in the mix, theres a cam cleat with a toothy grip that doesn’t let the line slip and makes sailing much less labor intensive.

But for all-around long-term use, the test team found it hard not to like Antals new OPF70. The quality of craftsmanship and design detail are there, but the $563 price tag makes it a challenge to afford.

Harken has long been the force to reckon with when it comes to quelling friction and knowing what competitive sailors like to handle. Ratcheting sheet control is a worthwhile feature for those with more sport boat than crusty cruise. Harken shackles are superb and the materials they use make sense.

Give the sheave of a Garhauer fiddle block a little spin, and it whirls around like a Vegas roulette wheel. But what our testers were really impressed with was how these blocks minimized friction under load. Equally as compelling was the pricing that tallied up to the lowest in the group, and included 40 feet of 3/8-inch double-braid line with an eye-spliced end. On the downside, secondary sheave diameter and the lead between the fiddle blocks cause minor line-to-line rubbing, and theres no angle adjustability to the cam cleat. But when price and performance are a priority, the Garhauer stainless and aluminum systems get the nod as the PS Budget Buy.

If you sail a smaller, lighter, lower sail-area boat in this size range, the compact Nautos ratchet-equipped fiddle blocks are worth a close look. They kept up with competitors, but with a lower safe working load, they are better suited to smaller boats.

Deck Hardware
The test setup:
Mainsheet Tackle Bench Test
1. Comparing cam gripping and releasing side-by-side.
Mainsheet Tackle Bench Test
2. A strain gauge was used to maintain consistent loads.
Mainsheet Tackle Bench Test
3. All mainsheet systems were tested using an identical fixed load.
Mainsheet Tackle Bench Test
4. A spring-type tension gauge identified specific release loads.

VALUE GUIDE: Mainsheet Control Systems for 20 to 30 foot Sailboats (4:1)

ANTALOPF 7000707 / 00708C$563 / 3 years2,860 pounds1/2 inch (12 mm)Yes28 pounds16 pounds
GARHAUERStainless30US$125* / 10 years2,000 pounds3/8 inchNo24 pounds32 pounds
Aluminum30UAG / UAB$115* / 10 years2,000 pounds3/8 inchNo24 pounds32 pounds
HARKENCarbo 75 ratchet2690 / 2697$280 / 5 years1,212 pounds9/16 (14mm)Yes24 pounds28 pounds
NAUTOSRatchet92200 / 92703$137 / 5 years660 pounds, 880 pounds1/2 inch (12 mm)Yes29 pounds19 pounds
RONSTANSeries 6060RF64500 / RF64520$318 / 3 years2,200 pounds, 1,155 pounds7/16 inch (11.5 mm)Yes33 pounds25 pounds
SCHAEFERSeries 5506-45 / 506-76$339 / 5 years1,500 pounds7/16 inch (11.5 mm)Yes26 pounds30 pounds
SELDENPBB 60406-001-11 / 406-001-14$138 / 5 years2,420 pounds, 1,056 pounds9/16 (14mm)Yes28 pounds32 pounds
*Blocks and 40-foot sheet**Pull required to release cam under 200 pounds of tension
Beckets, Cams, and Sheaves
Mainsheet Tackle Bench Test
1. A bowline on the becket rubs on the line leading out of Harken’s fiddle block, but when an eye splice is used the line runs fair.
Mainsheet Tackle Bench Test
2. Garhauer blocks have large bearing surfaces, but even with an eye splice on the becket, lines make light contact.
Mainsheet Tackle Bench Test
3. Schaefer’s large, toothy cam grabbed lines abruptly, held them securely, and operated smoothly, but releasing it required more pull than some others.
Mainsheet Tackle Bench Test
4. Garhauer welds a tube onto the fixed-angle cam-cleat base; it is attached with a machine screw and nylock nut. Users must send the cam in to Garhauer for angle adjusting; it’s free.
Mainsheet Tackle Bench Test
5. The Nautos ratcheting fiddle block was light and compact, and its angle-adjusting cam cleat and becket made up for it lower SWL rating.
Mainsheet Tackle Bench Test
6. With both good form and function, the Antal swivel stop locks the D-shackle in line with the sheave, or perpendicular to it.
Mainsheet Tackle Bench Test
7. Ronstan eliminates the need for a becket by using a large diameter open axle on its fiddle block’s lower pulley.
Sheeting Setups: Mid-boom vs. End-boom
Mainsheet Tackle Bench Test
Mid-boom sheeting clears the lines from the cockpit.

For centuries, a battle between simplicity and sail-trimming efficiency has been waged. Racers love double-ended sheeting that leads to the outboard end of the boom, runs forward internally and exits the boom near the gooseneck, returning aft along the cabin coamings or through a sub deck alleyway. Many bimini-bedecked cruisers appreciate mid-boom sheeting with bails so far forward that the sheet behaves more like a vang/sheet combo.

The right mainsheet solution depends upon your own sailing preference, but a few general principles reign true. The further forward on the boom the mainsheet is attached, the more of a downward effect (vang-like) sheeting elicits. The resulting elimination of twist may or may not be desirable, but it’s part and parcel of the trimming process. It’s no surprise that almost every performance-oriented sailboat is designed with end-boom sheeting.

Another fait accompli of mid-boom sheeting is the increased bending moment this tackle arrangement delivers. Relatively thin-walled tube sections—such as a mast, boom, or spinnaker pole—can handle impressive compression loads, but when it comes to the fulcrum-like bending load linked to the mid-boom attachment of a mainsheet, such tube sections perform poorly. Even with multiple blocks spreading the load over several feet, those converting to mid-boom sheeting will want a boom with a bit more cross-section or wall thickness.

Mainsheet Tackle Bench Test
End-boom sheeting offers more sail-shaping options.

Attaching a mid-boom preventer has a similar downside for those sailing coastally in an ocean swell. All it takes is a rolling swell and an inadvertent dip of the outboard end of the boom into green water. With a preventer rigged in the middle of the boom, the unsupported load caused by the contact with the sea can break the boom. This is why many seasoned voyagers have the mainsail’s clew-end reef point sewn in higher than the tack, resulting in the elevation of the outboard end of the boom, and making it less likely to submerge; some also lead a preventer to the outboard end of the boom. But if ocean sailing is not in the picture, such encounters are much less likely.

The bottom line is that end-boom sheeting delivers more mainsail control but places the tackle in the cockpit. So if you are satisfied with the sheeting afforded by a mid-boom setup, with its short traveler, at least the cockpit will be free of flying tackle during a jibe, and there’s room to rig a permanent bimini. But if you are about to tackle a mainsheet makeover, it’s worth considering whether or not end-boom sheeting might be more up your alley

Darrell Nicholson
Practical Sailor has been independently testing and reporting on sailboats and sailing gear for more than 50 years. Supported entirely by subscribers, Practical Sailor accepts no advertising. Its independent tests are carried out by experienced sailors and marine industry professionals dedicated to providing objective evaluation and reporting about boats, gear, and the skills required to cross oceans. Practical Sailor is edited by Darrell Nicholson, a long-time liveaboard sailor and trans-Pacific cruiser who has been director of Belvoir Media Group's marine division since 2005. He holds a U.S. Coast Guard 100-ton Master license, has logged tens of thousands of miles in three oceans, and has skippered everything from pilot boats to day charter cats. His weekly blog Inside Practical Sailor offers an inside look at current research and gear tests at Practical Sailor, while his award-winning column,"Rhumb Lines," tracks boating trends and reflects upon the sailing life. He sails a Sparkman & Stephens-designed Yankee 30 out of St. Petersburg, Florida. You can reach him by email at