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Racing Mainsails: X-Drive Carbon

Arcona435 Minimal partial taffetaBW
Depending on the boat size, performance level, weight and price, carbon X-Drive load-path fibers can be bonded to laminates reinforced with aramid scrims as shown above, or laminates reinforced with polyester scrims. Both laminates can gain chafe protection with a taffeta layer; the extra longevity comes at the price of extra weight and cost. Shown above is an Arcona 465 whose mainsail leech has a partial taffeta strip to protect the sail from flogging and UV damage when the sail is flaked on the boom.
X332 Sophie
Above is the X332 SOPHIE racing with X-Drive Carbon sails.

Carbon fiber is the highest-performance yarn used in sailmaking. As seen below, carbon yarns are at the top of the chart in three out of four ways to measure their performance.  Carbon fiber’s resistance to stretch is three times greater than S-Glass yarns, which are three times more stretch resistant than polyester yarns.

The almost complete coverage of continuous load path yarns on the sail leads to a smooth flying shape. UK Sailmakers’ yarn laying machine puts down up to 11 yarns at a time, which means there are hundreds of continuous yarns on the sail. Since each yarn has 4,000 carbon filaments there are up to 44,000 filaments of carbon are laid at a time, giving the sail great strength along with the ability to keep its designed shape without distortion. This means UK Sailmakers can use lighter and less expensive laminates and those savings are passed on to sailors.

All the carbon yarns used in X-Drive yarns are dry (not coated in glue) which keeps them from becoming brittle. Keeping the carbon yarns dry improves their flexibility.

X DriveCarbonMainVid
X-Drive Carbon main video. The continuous carbon fibers are on a black polyester laminate.
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Carbon X-Drive on laminate with black yarns making a square-top main.
X Drivedetail
A close up photo taken near the tack of a mainsail showing how closely spaced the X-Drive yarns are on a sail.

UKSailmakersX DriveCarbonMainsailYarns

Batten Configuration Options



For maximum roach racing mainsails, UK Sailmakers builds sail with a  full-length top batten. The batten running leech to luff stabilizes the leech while projecting the narrowest part of the sail fully.



For sails with extra roach or that have a lower aspect ratio, we offer two full-length top battens. The combination of full-length upper battens and shorter battens in the rest of the sail combines the best of both batten systems. The full-length battens support the large roach and add longevity to the highly loaded head section of the sail. The shorter battens reduce weight and allow for better sail shape control.



Racing sails with full-length battens are used by ocean racers and shorthanded racers where sailing conditions and sailhandling can be more extreme requiring extra durability. Mainsails with all full-length battens last longer because the long battens prevent flogging, the violent snapping back and forth that occurs when tacking, reefing, hoisting or lowering the mainsail.

Titanium Sq Top Left 1 e1665594637582


Square Top mainsails improve performance by increasing the sail area at the top of the mainsail. By avoiding having a pointy head, the sail gets air flow across this wider section, which reduces drag. These sails improve upwind and downwind speed.

Extra Durability With Lite Skin® or Taffeta

To help protect today’s sails and extend their peak performance lives, UK Sailmakers can build all our X-Drive racing sails where one or both sides of the laminate is fully covered with a lightweight finely-woven polyester taffeta. Not only does taffeta protect the film layer from abrasion, but it also prevents cracking of the film and reduces creasing. While taffeta doesn’t add any strength, it does make sails last longer. We also offer the option of putting a layer of taffeta over the X-Drive load path yarns only on the leech of the sail as shown below.

Lite Skin, is a thin, lightweight sheet of random, non-woven, polyester filaments applied to what will be the outer sides of the sail giving the sail a mat-black or dark grey appearance. Lite Skin is a proprietary product of Dimension-Polyant Sailcloth.

Taffeta is a lightweight, finely woven polyester cloth. Taffeta is slightly heavier than Lite Skin but it also more rugged. Taffeta is available in white or a medium grey color.

Partial Taffeta Option

Shown above is a main with taffeta on one full side and over the load path carbon yarns on the second side.
SantaCruz50X DriveMainwithLiteSkin
An X-Drive carbon main with Lite Skin on a Santa Cruz 50.
GreyTaffetaX DriveGenoa
An X-Drive jib with grey taffeta.

The leech of any sail benefits from having extra taffeta protection. Adding taffeta to the leech of an X-Drive mainsail reduces the destructive effects of leech flutter, luffing and flogging. Mainsails can flog in heavy air as the boat is de-powered and when the sail is being hoisted or lowered. Leech flutter happens when the leech line is not properly tensioned. The X-Drive construction method allows sailors to choose a sail with taffeta on one side of the sail, on one side and on the leech of the second side, or fully covering both sides. The more taffeta, the more protection — at the cost of more weight aloft.

UK Sailmakers will work with you to determine the right amount of taffeta to add to your sails based on your boat, the kinds of sailing you do, and your budget. Having both sides covered with taffeta makes a sail more durable, but also would make the sail heavier. UK Sailmakers offers a Partial Taffeta option to save weight and cost.

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