Mast sheave box - Compatible Ronstan part?

[Ben16737]

Hi all, I’ve been away from this forum (and sailing in general) for some time as life moved me in other directions, but I’m finally doing long overdue maintenance to get me back on the water. Among other things, I need new sheave boxes for spin and job halyards.
Hoping someone has already solved this problem - What current Ronstan product is the equivalent to RF459? That’s what I pulled out of the mast, but they no longer make that part. From looking at their site, I think RF41712 would do the trick, but not sure.

Background info: I have an 86 Capri 22. The main and jib halyards appear to be 3/8, and the spin halyard looks smaller - 1/4”?

I appreciate any advice.
*Edited to add photos

 

[jssailem]

Ben.. Here is a link showing sheaves, a mast head fitting and an attachment called a "crane"for a spinnaker halyard.

Masthead

Catalina Direct, publishers of the Catalina 22 and Catalina 25 Owner's Handbooks and the largest supplier of parts and Lewmar winches for Catalina Yachts in the country

www.catalinadirect.com

 

[Ben16737]

Ben.. Here is a link showing sheaves, a mast head fitting and an attachment called a "crane"for a spinnaker halyard.

Masthead

Catalina Direct, publishers of the Catalina 22 and Catalina 25 Owner's Handbooks and the largest supplier of parts and Lewmar winches for Catalina Yachts in the country

www.catalinadirect.com

Thanks, I’ll check it out. Also added pics to my original post to show what I’m looking for.

 

[Ben16737]

I went ahead and ordered what I think is the right part, everybody cross you fingers for me!

 

[jssailem]

Just looked at the added pictures. It is a standard in mast box sheave. Typical for a jib halyard on a fractional rig (not a mast head)
Yes the sheave has broken down. Time, use, and UV just wear the parts out.
There are similar parts available from a number of stores. Looks like you drilled out the rivets.
Your on the right track.

 

[jssailem]

Ben, here is a link to an Ullman sail rigging guide. May be of help.

https://ullmansails.com/wp-content/uploads/2016/03/Ullman-Sails-Capri-22-Sailing-Guide.pdf

 

[jssailem]

Here is the “exit block” you seek from Catalina Direct.

Exit Block Single CP-22 Early Production

Catalina Direct, publishers of the Catalina 22 and Catalina 25 Owner's Handbooks and the largest supplier of parts and Lewmar winches for Catalina Yachts in the country

www.catalinadirect.com

You may find the same at a better price point. If longevity is a factor I would seek the best sheave material. The white plastic in the cheaper products tends to break down sooner then the higher quality Delrin sheaves.

 

[Ben16737]

Here is the “exit block” you seek from Catalina Direct.

Exit Block Single CP-22 Early Production

Catalina Direct, publishers of the Catalina 22 and Catalina 25 Owner's Handbooks and the largest supplier of parts and Lewmar winches for Catalina Yachts in the country

www.catalinadirect.com

You may find the same at a better price point. If longevity is a factor I would seek the best sheave material. The white plastic in the cheaper products tends to break down sooner then the higher quality Delrin sheaves.

Thank you! That does look exactly like what I need. So that gives me a backup plan if the ones I just ordered from Ronstan don’t do the trick.

 

[Ben16737]

Here is the “exit block” you seek from Catalina Direct.

Exit Block Single CP-22 Early Production

Catalina Direct, publishers of the Catalina 22 and Catalina 25 Owner's Handbooks and the largest supplier of parts and Lewmar winches for Catalina Yachts in the country

www.catalinadirect.com

You may find the same at a better price point. If longevity is a factor I would seek the best sheave material. The white plastic in the cheaper products tends to break down sooner then the higher quality Delrin sheaves.

Thanks for the info. I’m still struggling - I got the Ronstan RF41712, and it would be a perfect fit except it’s too thick to go in the slot in the mast. It’s 11/16”, and the original is 9/16”. The Catalina Direct offering you listed says the mast slot must be at least 3/4” wide, which is even bigger than the Ronstan part I just bought that doesn’t fit.

I’m going to call the nice folks at Ronstan today and see if they have anyone knowledgeable that can walk me through this. Any other advice, much appreciated!

 

[Sailor Sue]

If I understand what you're saying, your existing opening is an eight (1/8") of an inch too narrow. That's 1/16" per side. Should be able to file that small amount of aluminum quicker than waiting for a replacement part.

 

[Ben16737]

You may be right. Just got off the phone with Tommy at Ronstan (who was very helpful) and that was one of his suggestions as well. The part I pulled out of the mast hasn’t been in their catalogue for 20 years, and there is no exact match. The one I already ordered is about as close as it gets.