By: Andy Camarda
Most roller furling headsail systems allow you to shorten sail by partially rolling up the jib or genoa, reducing sail area to control heel and leeway in heavier wind conditions. This helps balance the boat, especially when the mainsail is reefed. While this is a quick and effective way to depower, sails designed for roller furling need specific features to maintain durability and performance.
Load Shifts and Reinforcement
When roller reefing, the primary loads on the luff shift aft, moving away from the reinforced corners to where the roll meets the furler. This creates stress in areas that aren’t typically reinforced on non-reefing sails. To address this, we extend the corner patches further down the foot and leech—typically covering 20% of the foot length, with markings at 10% and 20% for repeatable reefing settings.
On composite sails like our Expedition Cruising series, additional reinforcing fibers are integrated along the luff to strengthen these load-bearing zones, ensuring long-term durability under reefed conditions.
The Problem of Luff Depth
One of the side effects of roller reefing is reduced luff tension. As a sail furls, the leading edge can become fuller, increasing power—exactly the opposite of what’s needed in high winds. To counteract this, we add a foam luff (a series of foam strips) or twin tapered ropes along the luff. These inserts help maintain shape by compressing when furled, forcing the sail to roll more evenly and retain a flatter profile, reducing power and improving performance when reefed.
Foam Luff or No Foam Luff?
Foam luffs are beneficial for boats that are often overpowered, whether due to design or frequent sailing in high-wind areas. We strongly recommend them for offshore cruising or for boats with large genoas that can easily overpower the rig.
However, if your boat primarily sails in lighter air venues or remains balanced across its typical wind range, a foam luff is often unnecessary. Racing boats, in particular, tend to avoid them since the added material slightly disrupts airflow at the leading edge, making telltales harder to read and causing minor performance loss—something critical in competition but negligible for offshore cruising.
Ultimately, the decision to add a foam luff depends on your sailing conditions and priorities. If reefing is a frequent necessity, a foam luff can make a significant difference in maintaining sail shape and performance. But if you rarely reef or prioritize clean airflow over reefed efficiency, skipping the foam luff may be the better choice.
