Im just prepping my mast for removal and noticed these halyard sheaves didnt look too healthy. Are the wheels meant to turn? My jib and main ones dont. They are quite worn also
If those were fitting in your mast
find a size off this link and dont use sheaths www.ronstan.com.au/marine5/range.asp?RnID=109
No moving parts = last forever
Don't think that will work HG, the Top Hat halyards come out of the mast almost at the deck and turn at right angles back to the cockpit.
They only work if the load direction doesn't change
Steve your rigger can get new sheaves or you will have to find a replacement among Ronstan's stuff.
Mine were Ok, so did not have to fix or replace when I did Seaka's mast.
Cant i just replace the wheels/bearings. Im the rigger 
Mine dont come out near the deck. Theyre quite high up the mast.
Can anyone tell me if these sheaves are non turning sheaves? Theres no washers or anything which makes me think theyre not meant to.
They are meant to turn. The halyard will dig into the nylon if they don't and create a groove increasing friction.
Thanks MB. I recently upped the diameter of the halyards from about 5mm to 8mm. yes they were very thin the old halyards. I should be able to keep the old sheave holders and just put in new wheels that turn and fit my new halyards.
Some people just remove them and run the halyard out the mast hole
The less moving parts on a boat the better 
Select to expand quoteSectorsteve said..Select to expand quoteCant i just replace the wheels/bearings. Im the rigger
Mine dont come out near the deck. Theyre quite high up the mast.
Can anyone tell me if these sheaves are non turning sheaves? Theres no washers or anything which makes me think theyre not meant to.
These are what are called plain bearing sheaves. They just spin around a single axel/pin supported by a bushing. Provided you can remove the pin/axel you can get another sheave.
Ball bearing sheaves will have (as the name implies) lots of ball bearings which means they spin with less friction so are faster. The down side is that they have a lower working load and can wear faster.
Select to expand quoteStratussailor said...Sectorsteve said..Cant i just replace the wheels/bearings. Im the rigger
Mine dont come out near the deck. Theyre quite high up the mast.
Can anyone tell me if these sheaves are non turning sheaves? Theres no washers or anything which makes me think theyre not meant to.
These are what are called plain bearing sheaves. They just spin around a single axel/pin supported by a bushing. Provided you can remove the pin/axel you can get another sheave.
Ball bearing sheaves will have (as the name implies) lots of ball bearings which means they spin with less friction so are faster. The down side is that they have a lower working load and can wear faster.
Thanks! Luckily the pin and axel come out easy so we should be right! Replacement plain bearings are only $5.
No worries. Just make sure the centre hole of the sheave fits the pin/axel for smooth rotation. $5 is very cheap! Are they Ronstan?
Select to expand quoteSectorsteve said..
Mine dont come out near the deck. Theyre quite high up the mast.
That makes a difference Steve, HG's idea would work quite well
Select to expand quotenswsailor said...Sectorsteve said..
Mine dont come out near the deck. Theyre quite high up the mast.
That makes a difference Steve, HG's idea would work quite well
I thought i might splash out and get actual ball bearing sheaves for low friction especially for the main as i pull it up manually from cockpit. Mast winches are gone and now an ornament in my garden. Im wondering what would be less friction. Hgs ronstans or ball bearing sheaves.
Re thinking it a bit: these non bearing sheaves would have to offer resistance under load so not ideal for my fully battened main which, the other day in a blow was a bit of a mission to raise. I only have cockpit winches at this stage. Not sure yet whether to get a cabin top winch as i only need a little winch action to get the main halyard tight which i can do with the cockpit winches. With ball bearing sheaves for the main i think we could have blissful smooth lowering and raising of the main. Theres been alot of talk of this on here lately and to me i think its important to get the main up and down as easily, and frictionless as possible.
I'm a little confused about what sheaves you are talking about here. For the masthead I would prefer solid non ball bearing sheaves. Now that you have removed the winches from the mast the fixed guides that HG linked to for where the halyard exits the mast and at the mast base, ball bearing turning blocks for leading the halyards back to the cabin top through a jammer to a winch and a back up cleat. A winch either side of the cabin top with jammers so the winch can be used for other stuff too like Cunningham eye, reefing lines etc. There will be more friction with cockpit operated halyards, especially with fully battened mains but the benefits far outweigh a little friction.
Perhaps you had wire halayards before and they needed the exit holes with sheaths and we're never changed out to suit rope halyards that what mine were
Corroded and stuffed
a very healthy mast with great halyards suitable for rope the stainless exits are there so the rope doesn't wear on the mast some people don't bother and just make enough room for the halyards to pass though some times they wear into the mast
Below what was on my old mast when it was fitted with wire halyards it could still be used but there no point as it only creates fiction
Select to expand quoteStratussailor said...
No worries. Just make sure the centre hole of the sheave fits the pin/axel for smooth rotation. $5 is very cheap! Are they Ronstan?
Yes theyre ronstan from whitworths
Select to expand quoteHG02 said...
a very healthy mast with great halyards suitable for rope the stainless exits are there so the rope doesn't wear on the mast some people don't bother and just make enough room for the halyards to pass though some times they wear into the mast
Below what was on my old mast when it was fitted with wire halyards it could still be used but there no point as it only creates fiction
Hmmmm they look good aye.
Select to expand quoteHG02 said...
Perhaps you had wire halayards before and they needed the exit holes with sheaths and we're never changed out to suit rope halyards that what mine were
Corroded and stuffed
The halyards that came with boat were 5mm and went straight to mast winches. The sheaves were for 5mm rope. vive just PUT 8MM Halyards on. I think the original halyards have been on the boat since the first owners at the end of their time with the boat. No wire, just small diameter rope.
does the 8 mm rope fit on the sheaths ok I machined mine to suit 8 mm rope as before it would have been for 6 mm wire
Select to expand quoteHG02 said..
does the 8 mm rope fit on the sheaths ok I machined mine to suit 8 mm rope as before it would have been for 6 mm wire
Im still replacing the mast head as its really tight for room for 8 mm halyards(friction) . Should see me out .
Russ at south east yacht services is making me a new mast head. Hes just down the road from home.
Select to expand quoteSectorsteve said..
I thought i might splash out and get actual ball bearing sheaves for low friction especially for the main as i pull it up manually from cockpit. Mast winches are gone and now an ornament in my garden. Im wondering what would be less friction. Hgs ronstans or ball bearing sheaves.
Re thinking it a bit: these non bearing sheaves would have to offer resistance under load so not ideal for my fully battened main which, the other day in a blow was a bit of a mission to raise. I only have cockpit winches at this stage. Not sure yet whether to get a cabin top winch as i only need a little winch action to get the main halyard tight which i can do with the cockpit winches. With ball bearing sheaves for the main i think we could have blissful smooth lowering and raising of the main. Theres been alot of talk of this on here lately and to me i think its important to get the main up and down as easily, and frictionless as possible.
I know the feeling and always good to have minimal friction especially on the main which is why racers use ball bearing blocks everywhere. However
a good quality plain bearing block is almost as efficient as a ball bearing block.
Also the working load of a ball bearing block is lower than a plain bearing block for the same size sheave. This is why plain bearing are used for halyards where there are high static loads which eventually wear the ball bearings overtime increasing friction. The solution is to go for a larger sized ball bearing block (or roller bearings) but that depends on space and budget.
Of course a sailor who uses their boat a few weeks a year for cruising does not subject his blocks to the same stresses as the hardcore racer so the wear factor on ball bearings is probably not a big issue in this case.
You won't get half the life out of ball bearing blocks as plain bearing blocks, and when they spit out their balls you are back to high friction. In a mast exit situation there is not much load or friction anyway and HGO2s plain exits are perfectly OK - simple and non fail and very little chafe..
