The sheaves on my 86 H31 are more than tired and since I will be stepping the mast, this seems like the time to replace all of them. I would like to have them on hand before the mast comes down. Since these boats have passed their 3rd decade, I have to assume someone had replaced all the sheaves, top and bottom, on the B & R rigs Hunter used. Were they all the same size? Anyone know the dimensions? Part numbers?
Sheaves
- Thread starter wufibugs
- Start date
If your spars are by Z-spars, then you need to call these guys...
US spars bought Z-spars. I replaced all of the sheaves in my boom this spring. I called them, told them the year and model of my H26 and they mailed me a pouch with sheaves. Easy-peasy.
US spars bought Z-spars. I replaced all of the sheaves in my boom this spring. I called them, told them the year and model of my H26 and they mailed me a pouch with sheaves. Easy-peasy.
From what I read, during the 80's Hunters almost exclusively used B & R sticks. The 83-87 H31 used the Gen I B & R mast with backstay. I did as you suggested and contacted U.S. Spars to see if they can reference the sheaves. I also contacted Rig-Rite. If anyone has any vendor you think can supply these sheaves, I would certainly appreciate it.
You probably know this but B&R stands for Bermuda Rig and is not the name of a vendor. Do you have any serial numbers or stickers on your mast that will give you a clue to who made it?
For instance, this resembles my boom and is made by Z-spar (now US Spars)
Do the end caps on your boom look similar?
Alternatively, you can measure you sheaves with a caliper. This site sells sheaves if you know the diameter.
You might also try calling the SBO store. Many of the guys who work at this site used to work for Hunter.
For instance, this resembles my boom and is made by Z-spar (now US Spars)
Do the end caps on your boom look similar?
Alternatively, you can measure you sheaves with a caliper. This site sells sheaves if you know the diameter.
You might also try calling the SBO store. Many of the guys who work at this site used to work for Hunter.
As I recall, the 1985 H31 came with an Isomat mast system. It was an anodized aluminum spar that had molded in the front a pair of grooves for a nice wisker pole car. Does yours look like that? The H34 of the same era had a Kenyon spar which was painted white. The B&R refers to the design used for the rigging (swept back spreaders, diamond stays and eventually no backstay).
Allan, it is indeed an aluminum mast but I think it has a track on the front for a pole car similar to the jib car track on the deck. According to Wikipedia the mast used on the Hunters were of the Bermuda Rig family, but the Hunter masts were patented by Lars Bergsrom and Sven Ridder and I believe that's why they were named B & R rigs. However, as rgranger points out, that does not solve the mystery of who actually manufactured them.
Yeah, I had run down that road also, but am still unsure. I sent an email to US Spar. I'll communicate the answer when I get it.
I am in the same situation, 1984 H31 with the 42' Isomat Spar. My mast is down while the standing rigging is being replaced.
The sheaves at the base are 60 mm OD, 10 mm id, and 14 mm wide, there are 4 of them.
At the mast head (see photo) the sheaves at the front of the mast (right side of photo) are the same diameter as those in the base. The aft sheaves (left side of photo) are smaller 50mm OD, 10 mm id. Curiously there are two additional 50 mm sheaves in the center of the mast head casting that are unused and when i took them out for inspection they look pristine.
Any thoughts on the middle two?
I have submitted a quote to Rig-Rite, any other suppliers I should look at?
The sheaves at the base are 60 mm OD, 10 mm id, and 14 mm wide, there are 4 of them.
At the mast head (see photo) the sheaves at the front of the mast (right side of photo) are the same diameter as those in the base. The aft sheaves (left side of photo) are smaller 50mm OD, 10 mm id. Curiously there are two additional 50 mm sheaves in the center of the mast head casting that are unused and when i took them out for inspection they look pristine.
Any thoughts on the middle two?
I have submitted a quote to Rig-Rite, any other suppliers I should look at?
Bob. You might want to identify your mast head.
On rigrite site I found one that looks similar. It could explain the sheave set up as it described the purposes of the various fittings.
On rigrite site I found one that looks similar. It could explain the sheave set up as it described the purposes of the various fittings.
An industrial bearing supply. mine being Norfolk Bearing because I live in Norfolk sells delron shives. And can order just. About any size
A very productive discussion and I thank all for their contributions. I'm going to gamble that my mast is the Isomat NGI , same as bobmorning's and identified by John. One of the two extra sheaves is most certainly for a spinnaker halyard. I will use the second for a jib sock. Here in San Diego we pay for year-round sailing with almost 12 months of exposure to UV rays that virtually dissolved my headsail. I intend to protect the replacement with a sock.
Sail almost every Saturday and only missed one because of very high winds. Beer Can on Wednesdays but now that daylight savings is over it get's too dark too early for those that still have to work for a living.
Sail almost every Saturday and only missed one because of very high winds. Beer Can on Wednesdays but now that daylight savings is over it get's too dark too early for those that still have to work for a living.
Check with local rigging companies. They either stock sheave material and can make from their inventory or should know what size and where you can acquire. In Houston (Kemah area) Styx-N-Rigging has sheave material and made my deck turning block replacement sheaves. If u know sizes you can contact them if not able to get locally.
After doing some research, I reluctantly conclude that the stock size as measured by bobmorning is actually quite rare. I was unable to find a 60 X 14mm sheave with a 10mm axle. I got to thinking, however, that aside from making sure the axle fits the bores in the masthead, the other dimensions can be altered. I am replacing all the running rigging and went with 1/2" halyards. I suspect the stock 14mm width would be a tight fit for a 1/2" line. At least 16mm would be better. Similarly, the 2 1/4" [57mm] OD is easier to find than the 2 3/8" [60mm].
Don’t know if this helps but there is a company in the UK called EUROSPAR . They do parts from a french company who took over Isomat and are called SPARCRAFT and have Isomat spares. I obtain a mast foot for my Legend 295 . Found them very helpful
I have watched our rigger take a sheave designed for a rope/wire halyard and convert it for a rope only halyard by that same technique. Sand paper in a U shape applied to a spinning sheave, widening the groove to accommodate a rope not a wire.
We offer Selden and other brand name sheaves:
