Why tack the code halfway on the sprit?

Here’s a question from a reader and fellow J/111-sailor in Detroit.

Reminds me I need to sail on the Great Lakes at some point…


I own a J111 in Detroit USA. FREEDOM
We are getting a code Zero.
I notice that you might have your code Zero tack on a bobstay 1/2 way out your pole……why?, advantages and disadvantages….. secondly, I am guessing you got it measured differently…….. or is it cut the same for either location of tack?
great racing last week.

thank you So much.
we follow all your efforts on Blur j111.

James Cooper

There is a separate article on the setup: “J/111 Blur³ | Code 0 setup”

There’s a number of reasons we run it from 1 meter out.

1) Early on we decided we needed a super flat code 0, as we in light wind build apparent wind like crazy. So it’s bascally as big as possible and 50% half-width (not possible in all rules). Key here is to get MAXIMUM luff tension (as hard as humanly possible on 2:1 halyard + maximum backstay after that.

2) J/boats advised that the loads would be to big if we put it at the end of the sprit, but 100 mm out would be ok. Also the angle for the bobstay is much better.

3) We wanted to be able to connect/disconnect the code when a gennaker was hoisted without climbing the sprit. Solo sailing, I can reach the tack point from the relative safety of the pulpit (still scary).

4) The alternative would be a halyard lock and a 2:1 tackline. This is how most boats with a fixed sprit do it. But it’s costly, and requires modifications to the mast.

5) We’ve raced against J/111 #85 Dacapo, that run their from the end of the sprit: both a code (more liike the code 1 that are typical in IRC or on some of the boats in the US (ex Kashmir), as well as a J0.

Measurements: SLU SLE SFL SHW Area

Blur C0 15,74 14,00 8,75 4,82 = 69,47 m2
Dacapo C0/1 16,68 14,93 8,78 6,77 = 94,46 m2

Blur J0 15,84 14,65 5,75 2,82 = 43,27 m2
Dacapo J0 15,95 14,50 7,13 3,86 = 57,27 m2

Naturally Dacapos code have more area, but our shape delivers more punch at tight angles in TWA 80-90. And that the cross-over to the A5/A3 feels ok. On a long leg with TWA 100 they will crush us, but we seem to have an overall edge with our setup.

And as the J/111 is a weak boat, the code more often gets to big, rather than to small :-)

So, there’s not one easy answer – it depends on what you’re trying to achieve. But if I had to reconsider I’d probably do the same priorities again.


  1. F424 Sep 7, 2017 Reply

    1000 mm out I guess?
    Nice set-up!

  2. spud Sep 8, 2017 Reply

    Why do you have the sprit all the way out?
    Can´t you just have it out 1 meter and the sail at the end?

    • Author
      Peter Gustafsson Sep 8, 2017 Reply

      Because we want to be able to tack gennakers at the same time as the code is hoisted/rolled.

      the common scenario is that you’re on code, go to A3 as the wind moves aft, but then go back to code again. Now you just leave the code furled and ready to deploy.

      Also, with your setup you need an adjustable bobstay, which isn’t easy to do if you want some serious tension.

  3. Pelle Pedersen Sep 8, 2017 Reply

    Combination can be seen on this Picture.

  4. Rozgonyi Balázs Apr 16, 2019 Reply

    Hi! It looks the bobstay only supports the code? Do you move that forward when you have the genakker on or that is not supported? Also it looks like the bobstay is not connected to the pole but the bottom of the Furler. That’s a bit strange for me? How the forces would transfer?

    • Author
      Peter Gustafsson Apr 16, 2019 Reply

      We don’t think the bobstay is necessary for soft flying sails, just the ones with a luff cable (ie Code/J0).

      The thinking is to get ALL loads (bobstay + furler + Dyneema-line to end of sprit) in the titan ring, and NOT on the sprit itself. Ideally the only load on the sprit is inwards.

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