masthead sheaves Mk 2

rmccall · 2016-12-03 00:02:29

I know there has been discussion in past forums as to replacing the rope to wire sheaves, but I cannot find any mention of sheave sizes. If anyone knows, I would appreciate it so that I could have the sheaves prior to pulling my mast for replacement of the original sheaves.
Thanks
J Netherland
1974 Mk II, Water Rat
Fairhope Yacht Club
Fairhope, Alabama

KenPole · 2016-12-07 06:53:36

Planning to keep the wire-to-rope halyards or replace with all-rope? If the latter, I can help/
Ken Pole, Ottawa
1975 Mark III Santiva

rmccall · 2016-12-07 07:10:18

I am presently running all rope, which I realize isn't great, but when I bought the boat and stepped the mast I overlooked the sheave problem. Any help will be appreciated so hopefully when I drop the mast again I can correct my oversight. Unfortunately (or fortunately) we sail year round so don't really have a hard date for pulling although will probably do it some time this winter to be ready for spring racing.
J Netherland
1974 Mk II, Water Rat
Fairhope Yacht Club
Fairhope, Alabama

rmccall · 2016-12-07 07:10:46

I am presently running all rope, which I realize isn't great, but when I bought the boat and stepped the mast I overlooked the sheave problem. Any help will be appreciated so hopefully when I drop the mast again I can correct my oversight. Unfortunately (or fortunately) we sail year round so don't really have a hard date for pulling although will probably do it some time this winter to be ready for spring racing.
J Netherland
1974 Mk II, Water Rat
Fairhope Yacht Club
Fairhope, Alabama

Last edited by (2016-12-07 07:11:03)

carriden · 2016-12-07 17:54:06

I recently shifted from rope/wire to all-rope genoa halyards. I took my original sheaves to Klacko Spars, who supplied much of the original C&C hardware and rigging, and currently do custom work. Rather than trying to find replacement sheaves, they simply took my existing ones and re-machined the sheave profile to a smooth curvature for the rope. Since it was the end of the day, and the staff was not elbow-deep in other work, they did the work while I waited. I simply took the sheaves back down to the harbour and put them back in place.

Although the re-machining of the sheaves does slightly reduce the effective diameter of the rope-handling portion of the sheave, the experts at Klacko did not feel that the change in size was sufficient to make a material difference to the movement of the line. I have been using the modified sheaves for racing with a spectra line and have not experienced any issues. If you make arrangements with a local machine shop ahead of time, they can probably do the same work for you while you wait or, at worst, with a 24-hour turnaround. Re-machining an aluminum sheave should be a fairly simple job for any properly equipped machine shop. The process should also be less expensive than sourcing new sheaves with appropriate bronze bushings.
Marcus from Carriden

Mk III, Hull #847
Oakville, Ontario

rmccall · 2016-12-12 08:57:59

Thanks Marcus for the suggestion. I would still be interested in the sheave sizes in case my local machine shop is not as helpful as Klacko.
J Netherland
1974 Mk II, Water Rat
Fairhope Yacht Club
Fairhope, Alabama

rmccall · 2016-12-16 11:43:54

Ken. I neve really answered your question. I plan to continue to run all rope, thus the need to change or modify the sheaves. Youe expertise with sizes would be appreciated.
J Netherland
1974 Mk II, Water Rat
Fairhope Yacht Club
Fairhope, Alabama

KenPole · 2016-12-17 22:30:33

Apologies for slow follow-up, but finally retrieved info you requested. When I switched to all-rope a couple of years ago, I found that my 30-year-old sheaves were in poor shape (surprise!). I had seen ads in Good Old Boat for a sheave manufacturer, http://www.zephyrwerks.com, in Washington state. After a couple of email exchanges with the proprieter, Ed Louchard, I ordered three custom-milled Delrin sheaves with brass axle holes. I'm extremely satisfied with the results. Sheave diameter and width were, respectively, 3" and 0.562" and the axle diameter was 0.432". My halyards are 3/8". However, Louchard advises measuring sheaves which he said can vary boat-to-boat. Cost, including shipping was about $105 but they'll outlast me. On the other hand, you can follow up on others' suggestions about having your old ones machined. Season's greetings from snowbound Ottawa.
Ken Pole, Ottawa
1975 Mark III Santiva

This information will be added to the Parts page in Black Arts if our ISP gets FTP working properly again. - Admin

Last edited by (2016-12-19 07:18:26)

rmccall · 2016-12-26 08:57:29

Thanks Ken I appreciate the information. Nice thing about this group is nine times out of ten someone has the experience or information needed.
J Netherland
1974 Mk II, Water Rat
Fairhope Yacht Club
Fairhope, Alabama

C&C 27 Association Forum

Announcement

#1 2016-12-03 00:02:29

masthead sheaves Mk 2

#2 2016-12-07 06:53:36

Re: masthead sheaves Mk 2

#3 2016-12-07 07:10:18

Re: masthead sheaves Mk 2

#4 2016-12-07 07:10:46

Re: masthead sheaves Mk 2

#5 2016-12-07 17:54:06

Re: masthead sheaves Mk 2

#6 2016-12-12 08:57:59

Re: masthead sheaves Mk 2

#7 2016-12-16 11:43:54

Re: masthead sheaves Mk 2

#8 2016-12-17 22:30:33

Re: masthead sheaves Mk 2

#9 2016-12-26 08:57:29

Re: masthead sheaves Mk 2

Board footer