sunfish mainsheet block update

early this spring, I laid out my plans to upgrade to a Sunfish mainsheet block for controlling/holding the mainsheet, as my current setup on the Sunfish left a little to be desired (but was better than nothing on my Super Porpoise).  here is the picture of my old set-up, a swiveling fairlead with a cam cleat to hold the mainsheet if I wanted.  I also had the old hook on the cockpit edge (the really old method used to hook the mainsheet and relieve the tension you had to hold with).

my original plan was based on a few posts over at the Sunfish Forum that recommended trying to use a low-profile swiveling cam cleat and modify it with an eyestrap and stand-up spring, and then add your mainsheet ratchet block of choice — similar to this diagram below:

but, the more I looked at the diagram, and thought about how this system would work, I couldn’t wrap my brain around something: after I fed the mainsheet through the ratchet block, and then the through the little strap over the cam cleat, I didn’t think I would be able to really take advantage of the ratcheting action of the mainsheet block.  turns out my suspicions were correct as noted here – scroll down to comment #38 on this post over at the Sunfish Forum.

I decided I’d instead go with a simpler and slightly cheaper route: I would just remove the old swiveling cam cleat, and install an eyestrap on the deck.  the mainsheet ratchet block would then connect to the eyestrap.  then, to give myself the option to cleat the lines in light air or similar situations, I removed the old hook, and added a standard cam cleat.  for my setup, I used the Harken 2135 57mm ratcheting carbo block and the Harken 150 cam cleat.

here is a picture of what the ratchet block looks like with the mainsheet running up to the sail, and the other end of the line held in your hand (picture is simulated – I didn’t want to set up the whole rig, so my 9-yr old son was just holding both lines up in the air).

here is a picture with the mainsheet fed through the ratchet block and then cleated in the Harken cam cleat, with a stopper knot tied in the end of the mainsheet.

I had also bought a stand-up spring that would keep the ratchet block standing upright, and prevent it from bouncing around on the Sunfish deck, but honestly – it was ridiculously hard to compress the spring down and then to try to slowly feed the little split ring onto the pin holding the ratchet block in place (in fact, I never did get it fully installed).  after talking a bit with other sailors at the Sunfish Forum – some have had success using zip-ties or something of that nature to compress the spring, then install the ratchet block, and then cut off the zip-ties.  most of them leave the ratchet block on permanently, though, and I wanted to be able to easily and quickly install mine before sailing and then remove it after sailing so that I wasn’t trailering the boat with the ratchet block flopping around.  so as of right now, I will probably skip the stand-up spring, but keep it in case I figure out a way to cover/protect the ratchet block while I’m trailering the boat.

overall, I’m extremely happy with the setup I have now.  I really enjoy playing the mainsheet through the ratchet block, and enjoy how the sheave on the ratchet block grips the mainsheet, so that the amount of pull I see is reduced, helping to keep my hands and arms from tiring as quickly.  I also like that this setup will force me to focus more on the sail trim, instead of just using my old setup to set it and then forget it.  I’d highly recommend this upgrade to other Sunfish sailors.

19 Responses to “sunfish mainsheet block update”

  1. 1 Andrew May 29, 2011 at 3:03 pm

    I’m trying to put together a similar setup on my much-loved Sunfish. How do you mount the cam cleat to minimize the chance of damaging the fiberglass in high-wind conditions?


    • 2 my2fish May 30, 2011 at 8:29 am

      Andrew, I just mounted it with bolts and the bigger sized (fender?) washers through the fiberglass lip at the cockpit. I would NOT have the mainsheet cleated in high winds, though. I only cleat the line in very light winds, and only briefly to grab a drink or adjust my position.

      I’ve heard that some people use a backing plate (made of steel, epoxied wood, or even cut up pieces from those plastic cutting boards) for when they mount the mainsheet block, but I didn’t use anything other than those fender washers. for the mainsheet block, the backing might make good sense – but for the cam cleat, I don’t think it should be loaded in high, strong winds, so I don’t think you should need the backing there.


  2. 3 Shoreline Sailboats (@Shoreline_Sail) April 13, 2013 at 3:26 pm

    I see what you are saying about the fairlead on the cam cleat. The line angle through the block is too low. If you take the fairlead off the top of the cam cleat it would be become a crazy moving target. This is a good fix!


  3. 4 Anne June 15, 2014 at 10:45 am

    I bought the same block for mine and am installing it today. I’m fixing up an older sunfish as well. Love your blog.


  4. 6 Steve Kelley July 16, 2014 at 11:18 am

    Maybe I misunderstand the ratcheting block, which is much more popular than I would have thought. I’m all in favor of having what might amount to a third hand while sailing my Sunfish, which a cleat would do, but a ratcheting block would seem unsafe to me, as it would prevent you from quickly releasing the sail in an unexpected increase or direction change of wind. And the “on/off” on these ratcheting blocks seems awfully small and difficult to switch on and off. So…do I misunderstand the idea of a ratcheting block?

    (1990 Sunfish, bought 2014)


    • 7 my2fish July 16, 2014 at 12:05 pm

      Steve, the ratchet block never “locks” the mainsheet in place. it just uses friction on the face of the sheave block to grip the line, and reduce the pull your hands ultimately see. that is, once you loosen your grip or let go of the mainsheet, then the force on the sail will pull the line through the block.

      I never use the on/off switch on my 2135, although I guess in really light wind you might turn if off so the block can spin freely.

      the real area to be careful with is with the cam cleat – that will lock your mainsheet control in position, and a sudden gust can flip you over for sure. by mounting my cam cleat on the cockpit lip, it forces me to only use the cam cleat in very light winds. with my newer Sunfish (a 2000), I didn’t even mount a cleat – I just always sail with the mainsheet in my hands.


  5. 8 cwkaiser August 2, 2014 at 1:52 pm

    Hi fish2: What size screws do you use to secure the clam cleat to the cockpit lip? Also, how much lift do you get from the fenders? 4 or 5 mm? your set up looks great and I am going to steal your idea for my new fish




    • 9 my2fish August 3, 2014 at 4:35 pm

      cwkaiser, I usually just carry the cam cleat into the hardware store and fiddle with a few sizes until I find a size that fits the best. for mounting the H150 through the cockpit lip, I think a #8 or a #10 machine screw with a large flat washer (fender washer) and the nylon lock nuts would work.


  6. 11 Glennnnnnnnnnnn February 23, 2016 at 8:35 pm

    I have a Sunfish knock-off someone gave me, with all Sunfish hardware. The issue I have is getting inside the bilge area to put a backing plate, washer, or nut. Do Sunfish have some kind of inside access to this area or do you have some other magic way of getting behind there? Thanks!


    • 12 my2fish February 23, 2016 at 8:59 pm

      Glennnnnn, if there is a lip edge around the cockpit, it is easy access. But if is like my Super Porpoise and the cockpit is just a depressed area molded into the deck – then there is not an easy fix. At that point, your best option will be to install a deck plate (or often called an inspection port). This will allow you to reach inside the hull to put a backing plate and fasteners for your hardware.


  1. 1 sunfish mainsheet block « my2fish: a blog about sunfish sailing Trackback on October 25, 2010 at 10:03 pm
  2. 2 10% off Harken at APS « my2fish: a blog about sunfish sailing Trackback on March 5, 2011 at 1:43 pm
  3. 3 mainsheet block stand-up spring « my2fish: a blog about sunfish sailing Trackback on August 4, 2011 at 9:19 pm
  4. 4 sunfish rigging knots | my2fish: a blog about sunfish sailing Trackback on June 7, 2013 at 7:46 pm
  5. 5 sunfish mainsheet controls upgrade | my2fish: a blog about sunfish sailing Trackback on June 3, 2016 at 7:02 am
  6. 6 10% off Harken at APS | my2fish: a blog about sunfish sailing Trackback on June 15, 2020 at 2:16 pm

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 1,531 other subscribers

my2fish archives

my2fish stats

  • 678,415 hits

%d bloggers like this: