Backstay adjusters allow racers and cruisers to adjust and control mast rake and headstay tension. Adjusting the backstay shapes the main to optimize upwind and downwind performance. On racer/cruisers, tightening the backstay increases headstay tension for upwind sailing, while loosening the backstay offwind reduces weather helm. When selecting blocks or systems for backstays, make certain blocks match or exceed the wire or line breaking strength.

Typical Boat Length:
Small Boat: 22' - 28' (6.7 - 8.5 m)
Midrange: 29' - 34' (8.8 - 10.4 m)
Big Boat: 35' - 42' (10.7 - 12.8 m)

6:1 Right Angle

This simple 6:1 system is used on small cruising boats with a single line or wire backstay.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.	Big Boat Part No.
A	Triple	344 2640
B	Triple	347 2648

12:1 Cascaded

This cascading 2:1/6:1 system provides a 12:1 purchase and is used on small racer/cruisers and daysailers.

Diagram Ref.	Description	Small Boat Part No.
A	Single	300
B	Triple	344 2640
C	Triple	347 2648

4:1 Split Backstay

This 4:1 system is used on small keelboats with split backstay systems. Pinching the wires together tightens the backstay and increases headstay tension to flatten the genoa, decrease weather helm, and stabilize the rig in heavy air.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.
A	Single	304	304 308
B	Fiddle	2655 2621	2621 1559
C	Fiddle	2658 2624	2624 1556

8:1 Split Backstay

A more powerful version of the split backstay adjuster uses a doubling wire running through a wire block for a purchase of 8:1.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.
A	Single	304	308
B	Fiddle	2655 2621	2621 1559
C	Fiddle	2658 2624	2624 1556

6:1 Double-ended Split

This double-ended split backstay system leads lines forward to cam cleats mounted just ahead of the helmsman so adjustments can be made from either side of the boat.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.
A	Single	304 308	304 308
B	Single	2636	2600
C	Double	2638	2602
D	Stand-up	349 2652	2652 2600 & 369
E	Cheek	350 2644	2644 2606
F	Cam cleat	338 150	150

Backstay Adjuster

This adjuster is ideal for small racer/cruisers and daysailers. The handles fold down when not in use.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.	Big Boat Part No.
A	Backstay adjuster		B1722

Backstay Adjuster with Winch Handle

This powerful backstay system operates without hydraulics. It is an excellent choice for larger racer/cruisers. The stay tensioner adjusts using a standard winch handle.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.	Big Boat Part No.
A	Backstay adjuster		B500 B501	B502 B503
B	Winch handle		B8AL B10AL	B8AL B10AL

Backstay Adjuster with Winch Handle

This 2:1 backstay adjuster is for boats with a split backstay. To rig, replace the two lower wires with a single wire and add a runner block at the top of the split. Size the block to match the breaking strength of the wire.

Diagram Ref.	Description	Midrange Part No.	Big Boat Part No.
A	Runner	737 1991 1853 3013	3013 1855 3019 3024
B	Backstay adjuster	B500 B501	B502 B503
C	Winch handle	B8AL B10AL	B8AL B10AL

Backstay Adjuster systems

6:1 Right Angle

12:1 Cascaded

4:1 Split Backstay

8:1 Split Backstay

6:1 Double-ended Split

Backstay Adjuster

Backstay Adjuster with Winch Handle

Backstay Adjuster with Winch Handle