Jib Leads, Cars, and Inhauler
Controlling where the headsail sheet pulls from — and why a few inches of change transform the sail's shape
Jib Track, Cars, and Fore-Aft Position
The jib (or genoa) sheet runs from the clew of the sail through a block mounted on a car that rides on a track bolted to the side deck. The car's fore-aft position on that track is one of the most powerful headsail trim controls available — and one of the most neglected on cruising boats. The position of the car determines how the sheet's pull is distributed between two competing demands: foot tension and leech tension. Every inch of car movement shifts the balance between them.
Moving the car forward increases leech tension and eases foot tension. The sheet pulls more upward on the clew, closing the upper leech (reducing twist) and allowing the foot to become deeper with more curvature. This is useful in light air when you want the upper sail working hard — a closed leech keeps airflow attached higher on the sail where it would otherwise separate. In light air, twist is your enemy because the upper sail simply stops generating lift if it is too open.
Moving the car aft does the opposite: it reduces leech tension and increases foot tension. The sheet pulls more horizontally on the clew, opening the upper leech (adding twist) and flattening the foot. This is the correct response to heavy air — twist lets the upper sail shed power by allowing airflow to escape, reducing heeling force where it has the greatest leverage (high on the sail). A flat foot also reduces total sail depth, further depowering the headsail.
The diagnostic test is straightforward: ease the jib sheet slowly until the sail just begins to luff (the leading edge flutters). Watch where the luff starts. If the sail luffs at the top first, the car is too far aft — the upper sail is too open and stalls before the lower sail. Move the car forward. If the sail luffs at the bottom first, the car is too far forward — the lower sail is at a wider angle of attack than the upper and stalls first. Move the car aft. If the luff breaks evenly from top to bottom, the lead position is correct for the current conditions.
The even-luff test works in any wind strength. Make it a habit every time you change sails, change heading by more than 10 degrees, or notice a significant wind speed change. It takes 10 seconds and gives you an immediate, accurate answer about lead position.
You ease the jib sheet and the sail begins to luff at the top first. What does this indicate?
In heavy air upwind, you should move the jib car:
The Inhauler
An inhauler is a line that pulls the jib sheet lead inboard — closer to the boat's centerline. Standard jib tracks are mounted near the edge of the side deck, which sets a default sheeting angle determined by the boat's beam and track position. The inhauler overrides this default by pulling the sheet's effective lead point inboard, narrowing the sheeting angle. The effect is significant: a tighter, more closed leech, reduced twist, and a narrower sheeting angle that allows the boat to point higher.
When to use an inhauler: upwind in flat water where maximum pointing ability matters and the boat can tolerate the increased heeling force from a more closed headsail. In moderate wind (roughly 8-15 knots on most boats), the inhauler is at its most effective — enough breeze to fill the sail properly, not so much that the additional power creates excessive heel. In very light air, the inhauler can close the sail too much for the available wind energy. In very heavy air, the extra power and reduced twist make the boat harder to control — you want twist to depower, not less twist to add power.
Not all boats have purpose-built inhaulers. They are most common on racing boats where every degree of pointing angle matters. However, a simple inhauler can be rigged on almost any boat: mount a block on the cabin sole, the base of the mast, or a pad eye on the cabintop near centerline. Run a line from the jib car (or from a ring on the sheet itself) through this inboard block and back to a cleat in the cockpit. When you tension the line, the sheet's effective lead point moves inboard. Release it, and the lead returns to the standard track position.
The amount of inhaul matters. Too much narrows the sheeting angle past the point of benefit — the leech closes so tightly that airflow stalls and drag increases. Start with 1-2 inches of inhaul and assess the effect on boat speed and pointing. If the boat points higher without losing speed, add slightly more. If speed drops, you have passed the optimum. The sweet spot varies by boat, sail, and conditions — it is a control to adjust actively, not set and forget.
On a J/105 in 10-12 knots of breeze and flat water, the crew tensions the inhauler about 2 inches, pulling the jib lead inboard from the standard track position. The effect is immediate: the headsail leech tightens, the slot between main and jib narrows, and the helmsman can point 2-3 degrees higher without the jib luffing. Boat speed holds steady. As the breeze builds past 14 knots, the crew eases the inhauler back to the standard position to prevent excessive heel. In a lull back to 8 knots, they tension it again. This active management of the inhauler is a measurable advantage on every windward leg.
What is the primary effect of tensioning an inhauler?
In which conditions is the inhauler LEAST appropriate?
The Barber Hauler and Outboard Leads
The barber hauler is the functional opposite of the inhauler — it pulls the jib sheet lead outboard, widening the sheeting angle. Named after the Barber brothers who popularized the concept in racing, this control solves a specific problem: standard jib track positions are designed for upwind sailing, where a relatively narrow sheeting angle is appropriate. As you bear away from close-hauled to a close reach or beam reach, the wind angle changes but the sheet lead does not — the clew is being pulled to the same inboard position that worked upwind, which is now wrong.
Without a barber hauler or outboard track, the jib on a reach gets pulled too far inboard. The sail collapses against the spreaders and rigging, the leech over-tightens at an angle where you want it open, and the sail shape degrades into an inefficient, stalled configuration. The deeper the reach, the worse the problem. On boats with overlapping genoas, this is particularly severe because the large sail has even more area to press against the rig.
A barber hauler fixes this by providing an outboard pull on the sheet or jib car. The simplest version is a line from the jib car or from a ring on the sheet running outboard to a block on the toerail or an outboard pad eye, then back to a cleat or clutch in the cockpit. When tensioned, it pulls the sheet's effective lead point outboard, widening the sheeting angle and allowing the sail to set properly for reaching. Some boats have dedicated outboard jib tracks or adjustable cars with inboard/outboard capability built in — these accomplish the same function with less additional rigging.
The barber hauler is essential for boats that race or reach regularly with overlapping genoas. Even on cruising boats, reaching with a genoa that is pressed against the spreaders is inefficient and causes unnecessary sail wear. If your boat does not have a barber hauler and you frequently sail reaching angles, adding one is a straightforward improvement. A block on the toerail, a length of line, and a cam cleat are all you need. The improvement in reaching performance and sail longevity pays for the hardware quickly.
What problem does a barber hauler solve?
Which boats benefit most from having a barber hauler?
Adjusting Under Load
Here is the practical reality of jib lead adjustment: moving a jib car under load is hard work. Sheet tension creates friction between the car and the track, and that friction increases with load. In moderate breeze on a 35-foot boat, the jib sheet load can exceed 500 pounds — and the resulting friction makes the car resist movement stubbornly. You need techniques to manage this, or your perfectly planned lead adjustments will stay theoretical.
Technique one: ease, move, re-trim. The simplest approach — ease the jib sheet 6-12 inches, which drops the load enough to move the car freely, then re-trim. This works on every boat but has a drawback: you lose trim momentarily, which costs speed and disrupts the helm feel. On a cruising boat, the interruption is trivial. On a racing boat, the seconds matter. To minimize the disruption, the trimmer and the car operator coordinate: the trimmer eases, the car operator moves immediately, and the trimmer re-trims in one fluid sequence.
Technique two: car control lines with purchase. Most modern jib tracks have car control lines — typically a forward line and an aft line running through turning blocks to clutches in the cockpit. If these lines have sufficient purchase (2:1 to 4:1), you can move the car against friction without easing the sheet. This is the preferred method on racing boats because it maintains trim continuously. The key is that the control lines must have enough mechanical advantage to overcome the friction — many factory installations use 1:1, which is inadequate in any real breeze. Upgrading to a 2:1 or adding a fine-tune purchase block is a simple improvement.
Technique three: mark your positions. Use tape, pen marks, or the numbered holes on the track to establish repeatable positions for different wind ranges and sails. After each sail, document what worked: "J1 in 8 knots = position 5, J1 in 15 knots = position 7, J2 in 12 knots = position 4." This eliminates guesswork, reduces the number of on-the-water adjustments needed, and makes it easy for any crew member to set the correct lead without the skipper needing to micromanage. Over a season, you build a trim card that covers every sail and condition — set the car before the tack, not after.
Mark your jib car positions with a permanent marker or numbered tape before you leave the dock. Use different colors for different sails if you carry more than one headsail. This five-minute investment saves minutes of fumbling on every tack and gives you a starting point that is already close to optimal.
Never force a jammed jib car by wrapping the control line around a winch and grinding under extreme load. If the car will not move, the track or car bearing may be corroded, damaged, or fouled with debris. Ease the sheet first, inspect the track, and address the root cause. Forcing a jammed car can break the car, bend the track, or send the control line block flying when it finally breaks free.
What is the most effective way to move a jib car without easing the sheet?
Why is documenting jib car positions valuable?
Summary
The jib car's fore-aft position controls the balance between foot tension and leech tension — forward closes the upper sail (less twist), aft opens it (more twist).
Use the even-luff test: ease the sheet until the sail luffs. Top first means the car is too far aft; bottom first means too far forward; even luff means correct position.
The inhauler narrows the sheeting angle for higher pointing in moderate breeze and flat water — ease it in heavy air to allow twist and depowering.
The barber hauler widens the sheeting angle for reaching, preventing the genoa from collapsing against the rig — essential for boats with overlapping headsails.
Mark jib car positions and document settings by sail and wind range to build a repeatable trim card that eliminates guesswork.
Key Terms
- Jib car
- A sliding block carrier that rides on the jib track, through which the jib sheet runs — its position determines how the sheet's pull is distributed between the foot and leech
- Jib track
- A rail mounted on the side deck along which the jib car slides fore and aft, allowing adjustment of the headsail sheet lead position
- Inhauler
- A line that pulls the jib sheet lead inboard toward the centerline, narrowing the sheeting angle for tighter pointing and a more closed leech
- Barber hauler
- A line that pulls the jib sheet lead outboard, widening the sheeting angle for reaching — preventing the headsail from collapsing against the rig
- Sheeting angle
- The horizontal angle between the boat's centerline and the line from the jib clew to the sheet lead — narrower angles favor pointing, wider angles favor reaching
- Lead position
- The fore-aft location of the jib car on the track, which determines the vertical angle of the sheet's pull on the clew and thus the balance of twist and depth
Jib Leads, Cars, and Inhauler — Quiz
You ease the jib sheet and the sail begins to luff from the bottom up. What adjustment is needed?
In 20 knots of breeze upwind, a boat with an inhauler should have it:
On a beam reach with an overlapping genoa, the sail is pressing against the spreaders. What control addresses this?
Factory jib car control lines at 1:1 purchase are often inadequate because:
A trim card notes 'J1 in 8 kts = position 5, J1 in 15 kts = position 7.' What does the higher position number (further aft) indicate?
References & Resources
Related Links
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North Sails — Headsail Trim Guide
Comprehensive guide to headsail trimming including lead position, twist control, and sheeting angle optimization.
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Quantum Sails — Jib and Genoa Trim
Detailed articles on jib lead adjustment, inhauler and barber hauler use, and building systematic trim settings.