Plain bearing vs ball bearing blocks, and where?

[patrscoe]

I am in the process of replacing my older blocks along with a few line replacement.

All my old blocks appear to be plain bearing type. I read that you should not change out all your blocks with ball bearings or roller bearings blocks, as they tend to potentially flatten the ball or roller under high static loads. I am not sure if this is accurate or would anyone notice over time.

But if it is, does that mean that your halyard mast base blocks would need to be plain bearing type and mainsheet and boom vang should be ball bearing blocks?

Outhaul and cunningham plain blocks?

Any thoughts?

 

[Loren Beach]

Any thoughts?

Oh sure! Worth about two cents before Holiday discounts...
I have changed out all of the OEM Lewmar solid axle turning blocks at the base of the mast over the last 20 years. they all roll/spin just as nice as the day(s) they were installed.
I suspect that flattening the balls or rollers takes a LOT of force, and that Garhauer or Harken factors that in back in the design phase. Ours have been all Garhauer. This year saw the finish of the total upgrade to the running rig with the replacement of the OEM Lewmar solid axle organizers with new Harken's. Same attachment hole size, too.

 

[HerbertFriedman]

Loren , please clarify, Have you replaced the solid axle blocks at the top of the mast with ball bearing blocks, and same question about the organizer blocks?

 

[Christian Williams]

The general idea is that ball bearing blocks are not for continuous load, the way a halyard block is on a mast collar.

I last saw that stated by Yves Gelinas on the install sheet for his Cap Horn wind vane.

Matter of dollars and cents, mostly. Standard blocks are cheaper.

 

[Teranodon]

I replaced all the blocks at the base of the mast, and in the mainsheet tackle, with Garhauers. I recommend doing this.

I simply cannot believe that ANY load on a sailboat could noticeably change the shape of a steel bearing ball.

 

[Loren Beach]

Harken and Garhauer blocks have "plastic" compound bearings, and I know that both builders ID's theirs as Torlon. Tough stuff.

 

[Loren Beach]

Loren , please clarify, Have you replaced the solid axle blocks at the top of the mast with ball bearing blocks, and same question about the organizer blocks?

No, but a friend of mine did that years ago with a $$ Harken sheave for that large mainsail on his E-33RH.
This time around we sourced new sheaves for all of the masthead from https://www.zephyrwerks.com

Sheaves for masthead, staysails, booms, halyards — Zephyrwerks, The Sheave Factory

Zephyrwerks is The Sheave Factory! We make sheaves, both anodized aluminum sheaves and isomat sheaves. Get your sheaves customized to individual specifications for mastheads, staysails, booms, halyards, and for all sailboat rigging new and replacement sheave needs.

www.zephyrwerks.com

This guy uses a high load plastic and they have a stellar reputation in the rigging industry.

We replaced sheaves for main, jib, and both spinnaker 'wing' halyards with new ones from Zephyrwerks. All while the spar was down -- best time to refurbish everything!

 

[HerbertFriedman]

so, I gather that Zephyr does not use ball bearing but rather delrin and oil impregnated bearings. Garhauer and Harken use torlon ball bearings but no one seems to use steel for ball bearings. I did replace the mast blocks on my collar at the base of the mast several years ago with Garhauer to try to reduce friction, no problem observed. Now the two blocks at the top of my mast (spinnaker and spare halyards) are frozen and I want to replace the with the lowest friction block available. I am dealing with the yard and it is not clear what blocks they recommend but I will try to get them to use Garhauer since I think delivery will be quicker than with a custom supplier such as Zephyer.

 

[Christian Williams]

Right, sheaves don't use ball bearings. Static force, not necessary.

So if the force on a block is static, ball bearings unnecessary.

They're great for running rigging.

(posted simultaneously with Herbert)

 

[HerbertFriedman]

Thanks Christian, I understand the static load issue, My problem is the large force necessary to raise the mainsail. I have tried cleaning the track but I think the real solution is the Tides system, But short of that, I was hoping to reduce some friction using a ball bearing block at the top of the mast for the main halyard,

 

[Christian Williams]

You must have sheaves and internal halyards, I don't see how a block would work.

I think the Tides system for my 38 was somewhere around $1300, plus sailmaker to add the proprietary slides to the sail, and a new sail cover (the Tides makes a high stack on the boom). Really worth it.

My 9 oz. full-batten mainsail is still work to raise, but it comes down like a falling piano. Lighter mainsails must be easier all around.

 

[HerbertFriedman]

I apologize, I miss-spoke, I used the terms block and sheave interchangeably. To be clear, the sheave at the top of my mast for my mainsail halyard has frozen and I was considering replacing it with a ball bearing sheave to reduce friction.

 

[Loren Beach]

I apologize, I miss-spoke, I used the terms block and sheave interchangeably. To be clear, the sheave at the top of my mast for my mainsail halyard has frozen and I was considering replacing it with a ball bearing sheave to reduce friction.

Thanks for clarifying, and I had kind of assumed that anyway.
Good luck with the project.

 

[goldenstate]

I apologize, I miss-spoke, I used the terms block and sheave interchangeably. To be clear, the sheave at the top of my mast for my mainsail halyard has frozen and I was considering replacing it with a ball bearing sheave to reduce friction.

@HerbertFriedman

If I were in your shoes, my first task would be to get the existing sheave at the masthead freed and rotating. Then determine if it is worth ordering a replacement.

1. Replacing the sheave has the potential to be a huge Pain In The Rear.

Depending on how your masthead sheave axle is installed (mine is a knurled pin) if your sheaves aren't moving, the axle is likely to be murderously frozen. So, to remove it, you'll be hammering/heating/oiling (god forbid breaking) your old masthead cast piece in an attempt to repair the sheave.

2. Simply freeing the existing sheave will be a huge performance improvement.

If you are really hauling your halyard up over a 180 degree turn on a locked wheel, then of course you are having a heck of a time with your main. Just get it rolling and you will experience far more of an improvement than bearings or the SailTrack will be able to offer. Cheaper, easier, and very high return-on-effort.

Assuming you have a steel axle and an aluminum sheave, I would start with a squirt bottle of white vinegar, then move on to PB Blaster if that fails. If you are replacing the masthead sheave, this process of getting things loosened up will be a requirement regardless.

-Tom

 

[HerbertFriedman]

Just for clarification, the sheave for the main halyard is not frozen, only the ones for the spinny and (I think) a spare. I am 80 so I aint going up there anytime soon. Last year at haulout for a bottom job, I asked the yard supervisor to look at those two halyards because I was noticing a lot of friction. He sent a tech up using the yard crane and reported that both sheaves in question were indeed frozen. I dont know if he tried lubricants but suggested changing those sheaves but he warned of problems (dropped parts, etc.) and wanted permission since if there was a problem, he would need to pull the mast, $$$. Since I dont even have a spinny, I decided to "live with it". But at some point, these sheaves, and maybe the one remaining sheave that is not frozen, should be replaced, hence my question about replacing sheaves with standard bushing or ones with ball bearings. There is so much friction raising the mainsail that I need a winch to get past the first spreader, and on my E34 I should be able to do better, even with a heavy sail rated for SF Bay conditions.

 

[goldenstate]

Just for clarification, the sheave for the main halyard is not frozen, only the ones for the spinny and (I think) a spare. I am 80 so I aint going up there anytime soon. Last year at haulout for a bottom job, I asked the yard supervisor to look at those two halyards because I was noticing a lot of friction. He sent a tech up using the yard crane and reported that both sheaves in question were indeed frozen. I dont know if he tried lubricants but suggested changing those sheaves but he warned of problems (dropped parts, etc.) and wanted permission since if there was a problem, he would need to pull the mast, $$$. Since I dont even have a spinny, I decided to "live with it". But at some point, these sheaves, and maybe the one remaining sheave that is not frozen, should be replaced, hence my question about replacing sheaves with standard bushing or ones with ball bearings. There is so much friction raising the mainsail that I need a winch to get past the first spreader, and on my E34 I should be able to do better, even with a heavy sail rated for SF Bay conditions.

Makes sense, but the guy from the yard on a crane or a rigger in a bosun's chair with a bottle of PB blaster and a pair of pliers won't drop any parts. I find house contractors and boatyard guys are frequently pre-disposed to replacement rather than repair.

I suspect your track/slugs are the central problem if your main sheave is turning freely. I wound up with the Tides system. I did it the foolish, time-expensive way, (by myself) but with my mast down, which is a cost it sounds like you want to avoid.

Kevin (@K2MSmith) had a rigger install the track on his boat in Sausalito for a reasonable sum, if I recall correctly. He may have a tip/reference for a professional second opinion.

 

[Christian Williams]

I don't know how easy raising a main should be. Even with the Tides, it's still work. My mainsail sheave is original and no great shakes.

Here's a two-minute segment of my 45-year-old daughter jumping the halyard and then cranking up the last few feet. I am (somewhat) stronger, (maybe), but it's still work for me. She does it again at minute 05:30. The sail comes down at minute 20: 07. (view embedded videos using "watch on YouTube" for higher resolution)

 

[Loren Beach]

While our mast was down for much of a year, the last project was replacing all sheaves at the masthead. You have to secure those old sheaves so they do not fall out or go anywhere you do not want. One method is to use a small piece of tape and string to rotate around the sheave and give you a loop to hang onto.
For a Kenyon spar the axel pins are held in place with a welded-on SS tab on one end, and the screw that holds that tab in place is likely to be frozen to the alum. spar. Some moderate swearing will be involved.
Use an isolating substance around all of these parts when reassembling. Tef-Gel is the best for this, by far.

 

[HerbertFriedman]

thanks all for the info and advice

 

[Guy Stevens]

I last saw that stated by Yves Gelinas on the install sheet for his Cap Horn wind vane.

This is for a completely different reason. Almost all blocks are much better with bearings. Mast base blocks etc. The mast head sheaves I generally replace with solid self lubricating bronze bearings and better sheaves.
Yves and Eric and the cape horn don't crush the bearings so much as melt them. Most of the bearings in ball bearing blocks are various plastics that can be melted if constantly moving. (Which is generally only the case with self steering loads).
We did a study on these and had blocks made up with differing ball bearing composition from Garhauer. Indeed we melted the standard composition in about 1500 miles of steering, when replaced with higher heat bearings we have sailed over 3000 miles with no problems.
Not mentioned here is the fact that nylon "standard" blocks egg out under load and turn poorly under loads in almost all usages. Yes they are cheap, and they do suffer uv damage and are harder to use under load, but other than that standard nylon blocks are fine for light loads on things rarely used.
Guy