The Offshore Voyaging Reference Site

Rig Tuning, Part 3—6 Steps to a Great Tune

In Part 2 we defined our goals for rake and prebend. Now let’s do it.

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More Articles From Online Book: Sail Handling and Rigging Made Easy:

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  2. Don’t Forget About The Sails
  3. Your Mainsail Is Your Friend
  4. Hoisting the Mainsail Made Easy—Simplicity in Action
  5. Reefs: How Many and How Deep
  6. Reefing Made Easy
  7. Reefing From The Cockpit 2.0—Thinking Things Through
  8. Reefing Questions and Answers
  9. A Dangerous Myth about Reefing
  10. Mainsail Handling Made Easy with Lazyjacks
  11. Topping Lift Tips and a Hack
  12. 12 Reasons The Cutter Is A Great Offshore Voyaging Rig
  13. Cutter Rig—Should You Buy or Convert?
  14. Cutter Rig—Optimizing and/or Converting
  15. Cruising Rigs—Sloop, Cutter, or Solent?
  16. Sailboat Deck Layouts
  17. The Case For Roller-Furling Headsails
  18. UV Protection For Roller Furling Sails
  19. In-Mast, In-Boom, or Slab Reefing—Convenience and Reliability
  20. In-Mast, In-Boom, or Slab Reefing —Performance, Cost and Safety
  21. The Case For Hank On Headsails
  22. Making Life Easier—Roller Reefing/Furling
  23. Making Life Easier—Storm Jib
  24. Gennaker Furlers Come Of Age
  25. Swept-Back Spreaders—We Just Don’t Get It!
  26. Q&A: Staysail Stay: Roller Furling And Fixed Vs Hanks And Removable
  27. Rigid Vangs
  28. Rigging a Proper Preventer, Part 1
  29. Rigging a Proper Preventer—Part 2
  30. Amidships “Preventers”—A Bad Idea That Can Kill
  31. Keeping The Boom Under Control—Boom Brakes
  32. Downwind Sailing, Tips and Tricks
  33. Downwind Sailing—Poling Out The Jib
  34. Setting and Striking a Spinnaker Made Easy and Safe
  35. Ten Tips To Fix Weather Helm
  36. Running Rigging Recommendations—Part 1
  37. Running Rigging Recommendations—Part 2
  38. Two Dangerous Rigging Mistakes
  39. Rig Tuning, Part 1—Preparation
  40. Rig Tuning, Part 2—Understanding Rake and Bend
  41. Rig Tuning, Part 3—6 Steps to a Great Tune
  42. Rig Tuning, Part 4—Mast Blocking, Stay Tension, and Spreaders
  43. Rig Tuning, Part 5—Sailing Tune
  44. 12 Great Rigging Hacks
  45. 9 Tips To Make Unstepping a Sailboat Mast Easier
  46. Cruising Sailboat Spar Inspection
  47. Cruising Sailboat Standing Rigging Inspection
  48. Cruising Sailboat Running Rigging Inspection
  49. Cruising Sailboat Rig Wiring and Lighting Inspection
  50. Cruising Sailboat Roller Furler and Track Inspection
  51. Download Cruising Sailboat Rig Checklist
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Hi John,
this is really great stuff, however one thing keeps me pondering: in case you have no rodkicker and have your boom supported by a topping lift only, the weight of the boom will produce a pull from the mast top and a pressure point at the gooseneck, thus generating a pre-prebend that cannot be eliminated. In such a situation, would you advise to (a) remove the boom for setting initial rake and prebend, or (b) simply ignore this as the amount of inaccuracy would be so minimal it wasn’t worth the hassle?


And one more: your summary lists setting the rake before moving the mast base. But if I understand correctly moving the base will itself again alter the rake, so shouldn’t one redo step 2 if the mast base has to be moved?


Sorry, one more – when thinking this through I believe when adjusting prebend the rake might change (grow) as well – if I get you correctly the prebend should NOT change the rake, thus the prebend is reached by “bulging” the mast forward (a bit), more or less keeping the mast top at the same location. Am I correct?
I tried to make a sketch for this question here – – if I am correct the distance marked in green should be the same before and after setting prebend?

Drew Frye

A good read. A few thoughts that may have been in there, but I missed them.

My experience has been mostly with mutihulls, which like B&R rigs, have no backstay and generally no vang. This leads to several differences:
1. Mast bend comes primarily from raked diamond wires. Mainsheet tension may have some effect on fractional rigs, but it is minor.
2. If the mast rotates, this can have major impact on draft for two reasons. First the cord of the mast section is added to the draft. Second, rotating the mast pushes cloth into the center of the sail (prebend pulls it out, but a rotated mast is straight), increasing draft. Thus, it is common to over rotate off the wind and under rotate beating in heavy air.
3. Forestay tension comes almost entirely from mainsheet tension. Ease the main in a gust and the jib instantly becomes more full due to forestay sag, defeating part of what you were trying to accomplish. Thus, playing the traveller or reefing are better alternatives than a loose, twisted main. A small jib upwind is also a common solution, since it is hard to maintain a tight forestay. This is why it is common to see performance multihulls beating in heavy air with a small jib hauled out slightly to maintain slot, eased traveller, and a tight mainsheet.

Tyler Reeder

Hi John,

I unstepped my mast for the first time and had new standing rigging made last year. upon setup it appears the starboard aft side of the mast is touching at the partner. I used the original wood wedges for the first thousand miles to let the new rigging stretch before installing spartite. I got the boat leveled and installed a rieker 1 degree inclinometer, which is a great addition btw. using the plumb bob method my masthead is still off 3″ to port at the gooseneck but is just barely touching the afth starboard side at the partners….i can move the butt about1/16th” fore and aft but there is no play at the butt for athwartship adjustment. have you come across this? would it be better to have a bit of bend at the partners to allow for the spartite or let the starboard side of mast rest on the partners? thank you for the great article!


Vesa Ikonen

Hi John.

Seeing this whole process written down in an article does make it seem very laborious indeed. That’s what it felt like the first time I did it too.

However, for anyone contemplating giving up and just going with poor tune, I would like to share some encouragement:

Our boat has a longish keel with an attached rudder. It was always known for being hard to steer with an amazing amount of weather helm when beating in a breeze. So much so that I had to support both legs on a coaming, sitting sideways on the cockpit seat, and pull with both hands on the tiller like I was deadlifting weights any time a puff came along.

I started learning about sail trim, which did help some. But still, steering with one hand only was not possible in a stiff breeze.

Enter rig tuning. After spending two long days learning a process very similar to the one You describe, the result was simply astonishing:
the boat sails with one hand on the tiller, heels far less as tuning the rig helps flattening the sails much further, and weather helm is modest.

After learning with some trial and error, getting a good tune is easy and the process seems logical once learned – takes a few hours every spring nowadays.

As a bonus, proper rake & bend makes the boat look a lot better.

Time very well spent!!