J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Replacing Halyard & Sheaves - Advice Sought

Alex,

The J/30 and J/24 use the same size sheaves in the mast crane. There are two sheaves at the top. The Main Halyard Delrin Sheave is 1.75" OD x 3/8" ID x 1/2" wide with the Main Halyard Sheave Bronze Bushing 3/8" OD x 1/4" ID x 1/2" Wide.

Look at my old post at this link with the info. I bought new Delrin sheaves, pins and bushings from Annapolis Performance Sailing.

Your halyard is too thick and is probably binding in the mast crane. StaySet X is a good strong parallel core rope that is fairly low stretch, and has a good cover for the rope clutches. The recommended diameter is 3/8" to work with the sheaves and the stock rope clutch. Use this page as a guide for your rigging.

You can get Amsteel but if you aren't racing, there is no sense spending that kind of money. The StaSet X will last a long time and is much lower cost. I use 3/8" Endura Braid that has a Dynema core, but I race and don't want any stretch. It's more than double the cost per foot.

You probably want to lubricate the turning blocks at the base of the mast too. On Rhapsody, since I changed the sheaves and have a new halyard the main goes up and down very easy.

Now - for working on the mast.... You only have a single masthead halyard so it makes it difficult to work on the sheaves with the rig up. Best bet is to get a friend with a mast a little taller, tie the boats along side. Tilt the boats towards each other by crossing the jib halyards to the opposite boat and winching them together to pull the masts toward each other. I did this in a slip last spring to replace a broken main halyard. Check out this post with the picture.