J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Replacing spin halyard sheave

I'm looking to replace my spin halyard and sheave. Does anyone know the sheave and pin dimensions? Has anyone tried pulling out the jib box with the mast still up?

Slingshot is a '79, and I'd guess the box is near original. There are two wire jib halyards, and one rope spin halyard.

Thanks,
Grady

I had the sheave box off today on Rhapsody. It is not a simple answer because there are multiple sheaves fore and aft. The forward sheaves are the same diameter as the main halyard sheaves. On Rhapsody these are riveted in. The aft sheaves provide separation of the halyards through the center of the mast, hence different sizes and locations. I left the camera on the boat but will post pictures that I took today when I return tomorrow night.

Look on my blog at this link for the details.

Some teaser photos of the sheave box...

Thanks Bill. That is is the same Jib box I have. Rig-rite is now selling part K-11597-1 as a replacement, which they claim is much lighter. Do you have any idea how much yours weights?

With the existing sheaves being riveted in, you can drill the rivets out and replace them with cleaves pins.

Looks like we're pretty much stuck with rig-rite for the replacement sheaves. The sheaves are 31/64" wide, and 1/2" looks to be too fat to fit. I'm probably going to get the Nylatron replacements for the spinnaker and jib halyards.

I had a crazy idea to try and replace it with the stick up, but I've been told this is a bad idea, so I'm going wait until this summer, and do it when I drop the mast to inspect it.

Grady - not sure how much the box weighs, as I wasn't thinking about it when I was working on it. The box is stainless so does have some mass for its size.

If you replace flush rivets with clevis pins you'll need to notch the mast opening to get the box back in.

You could do this with the stick up if once the box is unscrewed, you slide it out, then lower it with the halyards in. You'd also need to work with a Dremel tool to notch the mast. I'd say wait if you can when the mast is down though.

so now as it seems that all J30s came factory issue with the ability for two spin halyards ... how many have actually run the second spin halyard? and what did you use for a exit hole in the mast?

Getting custom cut replacement sheaves here instead: http://zephyrwerks.com/.

I was not aware of the Rig-Rite K-11597-1 replacement sheave box.

Has anyone used this, or even priced it?

I've been contemplating this project for a long time - with the boat 4.5 hours away I really like the idea of a bolt-and-go solution.

-dan

I almost bought it last year but you have to change your forestay length to make it work. I think the pin is about 1" different than the old version. I do not remember if it is longer or shorter. So this ment futzing with my roller furler extrusions etc.

From what I remember it is quite a weight difference, particularly when it is 30 feet above the deck.

DB

The new one is $497. from the site:


How does this effect the class rule on forestay length? I think mine (with the old box) is at the class max. This doesn't indicate whether the hoist height changes for the jibs.