Problems with upwind performance on a J92

Ben Hall answers

Ben Hall joined Hall Spars & Rigging in 1984. The resident speed freak, Ben races the A-Class catamaran, and is a three-time North American champion. His envelope-pushing masts have led to tooling innovations for a wide range of craft. He is also Hall's leader in many development classes, including the maxZ86 and America's Cup rigs. Hall Spars & Rigging manufactures high-performance, autoclave-cured carbon fibre masts, booms, spinnaker poles, and reaching struts for boats from 40 feet LOA to Super Yachts. Hall Spars & Rigging introduced autoclave curing to spar making in 1992, and lead the industry in tonnage of autoclave-cured laminates. Hall’s knowledge, experience, and processes are unrivalled. Hall’s 100% autoclave curing has no equal when it comes to ensuring strength by eliminating voids and optimising fibre straightness. With factories in the U.S. (20-meter autoclave) and Holland (40-meter autoclave), Hall creates spars for clients around the world. Hall is the provider of spars to Alinghi, Swiss Challenger for America¹s Cup 2003.

John Nicholls asks:

I have recently started sailing on a J92 and the boat is a load of fun but its upwind performance is shocking. We sail in a PHRF fleet that includes J105's ,J80's and the legendary J24 - all of whom have a good ten degrees on us to windward. Now having used all the trimming tricks I know to make her point it is obvious to me that the rig needs some attention. The owner purchased a new set of Kevlar North's at the begining of the season but a couple of months ago we herd that most of the 92 owners immediately add about 8 inches in the forestay to get some more rake in the mast. I can see why.

What are the major effects of extending the forestay and raking the mast. Is it moving the CLR more aft. If not what? And or what else.

Once the forestay is extended, with reference to the mast but and through deck placement can you explain what would be the ideal characteristics we would be looking for and what would happen if we went to far. So we might go out and test positions to find the ideal.

The boats suit is a 150%, 130%, 110% head sails and main. How would these react to the forestay being extended? (they are not cut for a roller furler but are full hoist) would any adjustments need to be made?


Hi John,

Here are some basics to clarify what you probably already know.

The J/92 is reasonably successful sailing in PHRF fleets. Unless there's something dramatically wrong with your keel and rudder, the J/92 should have similar pointing ability to the J/105, J/24 and J/80 (certainly not 10 degrees lower!).

Mast rake is definitely a factor with many J Boats as they tend to have very neutral helm when set up with 'stock' headstay lengths. By increasing the rake, the helm goes from neutral (sometimes even lee helm in light air) to a bit of weather helm. Weather helm allows the boat to naturally sail upwind better.

The relationship between the headstay length and the butt position of the mast should be monitored so that a proper amount of prebend is maintained. If the forestay is extended 8 inches (which is a lot), then the butt should be moved forward -- maybe as much as 2 1/2 inches -- to maintain the prebend that best matches your mainsail.

The headsails will tell you if you¹ve gone too far with the rake. Headsails cut to the original rake will be a bit short on the hoist and may end up with the clews too low to sheet well.

Another indicator is running out of adjustment in your turnbuckles with the added rake.

By all means go out and try different headstay lengths and mast-butt adjustments. Keep an eye on the headsails and be sure you have enough turnbuckle adjustment to tighten up in heavy air. Any adjustments needed are worth the effort if it makes you go faster.

Ben Hall