Hi I've got an old Hawaiian pro line carbon boom and I'm setting up an adjustable outhaul on it.
If I want just one loop of rope through the clew eyelet its pretty obvious how to set it up. Also, if I use all 4 pulleys on the boom end its pretty obvious - but this does result in 3 loops of rope through the clew eyelet which tends to choke up on itself.
How do I lace it for just two loops of rope through the eyelet? I've come up with the following (see pics below):
Up the right side of the boom, through the lower opening an around BOTH pulleys on the underside, then out and through the clew grommet coming from the left side. Now around the upper pulley on the right side and back out, then through the clew coming from the right. Now around the top pulley and back down the left side of the boom. You'll have two loops offering 4:1 purchase. The only disadvantage is that the lines are headed in opposite directions coming through the grommet. If you just add a clew block such as the one below that problem goes away also and it's much faster to rig, too.
isthmussailboards.com/chinook-double-sail-pulley-outhaul.html
With the clew block you'd come up the right side, through the UPPER pulley first, then (around clew block and) now go through the lower pulley on the right and around both, coming out on the left side then around left side of block, back through upper pulley on the left and down left side of boom.
It's identical to the old Fiberspar boom end.
Get a Chinook outhaul pulley for the sail, one loop goes around each side, perfect for an adjustable outhaul setup. I have one for each sail so I do not need to remove them.
If you have a wide tail on your boom, the Chinook pulley is fine. However, with a normal narrow tail I used to catch my side forward running lines on the Chinook pulley when the outhaul was released for downwind. In that situation the lower-bulk Severne would have been better.
Some sails such as Maui Sails race sails had the pulley fitting built in to the sail. That was the best.
If, however, you have a sail with a grommet in the clew (most sails nowadays), either use the Chinook or Severne pulley or, better yet, use the Sailworks-style of adjustable outhaul. You have to get 8:1 multiplication overall. With the pulley you could use a single 2:1 multiplication on the boom arms. With a grommet, you have to use 2:1 x 2:1 on the boom arms, which the Sailworks AO provides.
Thanks all, I don't have a clew block - could I temporarily just use an old downhaul pulley or will that just fall out of the grommet?
I use chinook's but I want to try this one:
lisawindsurfing.com/#twist-lock-pulley