8:1 Harken 57mm ratch-matic blocks

My wife wanted christmas ideas for me so the 8:1 blocks came to the top of my list. This 8:1 system using Harken 2631 and 2632 blocks appear to be a very popular combination. I see the 2632 block is a triple 57mm with a single 40mm block and the 2631 is a quad block. Here is a link to one place to buy it.
https://store.catsailor.com/pc/viewPrd.asp?idproduct=7971
My questions are:
The 2632 recommends a max line of 3/8 where the 2631 has a max of 7/16. I am guessing the limiting factor is the 40mm single? Have people used 7/16 in these blocks or am I better off going with the 3/8 (10 mm) line?
Are these blocks as nice as they sound? Currently using 25 year old original H18 blocks with 3 upper single blocks.
Are there other 8:1 options out there that are similar?
Scott
Hobie 18M in Chicago

A tapered mainsheet would fix the diameter running through the smaller block pretty easily.
I think the 3/8 recommendation is b/c of the ratchet, though, not the size of the sheave of that extra block.
They certainly look like a serious upgrade to the 6:1's it sounds like you have. The one thing you might want to remember is the amount of mainsheet you need, and the amount you'll have to sheet in or let out will all increase.
Rob
Nacra 5.2
OKC, OK

Scott,
Yes, they are as nice and if you have never used this setup, it will be nicer than you will ever expect. The key though, is get a quality sheet, smaller and taper it. You will wonder how you ever lived with out it!
I'm using 8mm (5/16") Racing Sheet tapered down to 3/16" Amsteel and it is plenty big. My traveler end is tapered with a 1/8" Amsteel tail. Put your money into the mainsheet.
Philip

i purchased a triple top to replace the 3 single blocks that come stock on the Hobie 18. I had put them on hanging s hooks for easy removal but they would get tangled up.
i eventually upgraded the base block (on the traveler) and i liked it, but after about 1 year... i realized the Auto ratchet wasn't working so i called harken and sent it back. they replaced the ratchets (no questions or receipt needed) and returned it to me. This year i upgraded to the quad top.
I do very much like the system but completely agree with Philip... get quality line (like Robline racing sheet).
PS i use 10 mm racing sheet (8 was to small in heavy air and my local guys didn't have 9mm) and it runs great!
edited by: andrewscott, Dec 02, 2009 - 09:47 AM
MN3

I use a 7:1 and started out the 7/16" but it ran poorly through the blocks in light winds. I switched it out for 3/8" and couldn't be happier even in heavy winds even without a taper. I think the key is to purchase good quality main sheet with good grip properties (i.e. Robline, VPC, etc), that is more important in my mind than the difference in diamater 7/16 and 3/8. That being said if I sailed solo for 10 hours a time like Andrew I might change my mind.
Regards,
Dave
Dave Bonin
1981 Nacra 5.2



I use 10mm Salsa tapered to 1/4" vectran. Works great. The single braids are incredibly easy to splice. I can vouch that the salsa is incredibly soft, but I'm not familiar with the other dyneema blended single braids to know it compared to the others.
Rob
Nacra 5.2
OKC, OK





Most dyneema blends cleat fine, pure dyneema braids don't cleat well. Most web sites will tell you whether they are recommended for Main Sheet applications. Unless you are really serious I wouldn't worry about tapered lines too much. They roll nice but 3/8" line should be fine, and simpler (I'm not big on splicing myself).
Dave Bonin
1981 Nacra 5.2

Wolfman wrote: Most dyneema blends cleat fine, pure dyneema braids don't cleat well. Most web sites will tell you whether they are recommended for Main Sheet applications. Unless you are really serious I wouldn't worry about tapered lines too much. They roll nice but 3/8" line should be fine, and simpler (I'm not big on splicing myself).
I probably wouldn't have looked into splicing mine, but I needed a new mainsheet and I was in a cast for a few weeks this summer. I figured it was a good time to look into upgrades. Only about 7 or 8 feet (iirc, out of town atm) of the tail is tapered, and it definitely makes a difference on how well the line runs through the blocks. I have a 7:1 system; I'd have to have a higher ratio to use a longer taper. I actually think it would be better if I had a foot less of the vectran, but I'm not willing to cut it a foot shorter to experiment.
I don't agree with one line or another being 'simpler'. Once its tapered, you move on and enjoy the benefits...its just more work to get there in the beginning. It's not like I have to taper it every time I put the blocks on the boom.
I agree that 3/8's runs through 57mm blocks just fine, but I suggested it b/c the blocks in question also have that 40 attached, and the 40 should be the first sheave of the lower block that he uses....perfect setup for a tapered sheet.
Anyway, not trying to be argumentative, Wolf, but I'll stand behind the tapered sheet here. He needs a new one anyway.
andrewscott wrote: what technique do you use to taper from 10mm to 6.5mm (1/4") or do you purchase it?
Technically, I used the yale instructions for the most part:
http://www.yalecordage.com/pdf/yale_endforend_hi.pdf
IIRC, I used NE Ropes' instructions b/c it has illustrations instead of pics, which were easier to follow, but where they differ I followed Yale's instructions (which i think just differ in that yale has you pull the two through each other once or twice more than neropes.)
I lock stitched the splice, although it was my first time to do that, and it ends up in the cleat on occasion, and its pretty ugly now. If I ever notice it fray or start to come apart I'll replace it with a nicer stitch.
I also whip locked each end of the main sheet for whatever that's worth.
Another thing - I just bought end of spool sale lines with a focus on a thinner high modulus, and a thicker dyneema blend. There were quite a few options, which made it relatively cheap.
Rob
Nacra 5.2
OKC, OK

Yurdle, no problems. I just thought that it was easier to order one type of line over tapering. I glossed over the part about the 40, a 5/16" line would run better through that than 3/8". My blocks are all 57s so it doesn`t matter as much for me, but in this case a tapered line would have some definit benefit.
Dave Bonin
1981 Nacra 5.2

Technically, I used the yale instructions for the most part:
cool thanks for the data.
There is NO DOUBT tapered lines are wonderful!
I really want to move to a tapered main... but need to replace my 90' spin halyard with a tapered line first (as my current one burns holes in my spin every time)
MN3

So basically the tapered line runs through the blocks smoother while allowing you to hold on to a more substantial diameter line? I am new to the idea of using tapered lines, but presume if I buy my line from a good source they will do the splice.
I was looking at the APSltd site. Looks like I could taper to an amsteel line and then put an eye splice in the end of the amsteel to connect to the block without a knot.
I presume a good splice between line diameters runs through the blocks fairly well.
Scott
Hobie 18M in Chicago

So basically the tapered line runs through the blocks smoother while allowing you to hold on to a more substantial diameter line?
Yes
if I buy my line from a good source they will do the splice.
Yup, for a fee
I was looking at the APSltd site. Looks like I could taper to an amsteel line and then put an eye splice in the end of the amsteel to connect to the block without a knot.
exactly
I presume a good splice between line diameters runs through the blocks fairly well.
a good splice will have a nice long tail/tuck that has been correctly tapered and the transition is extremely smooth.
this is critical because HM line like dynema (amsteel/spectra,vectran,and others) lose up to 50% of their strength if tied in a knot (inside face of line holds no tension so the outside has double the load) or have a sharp curve to the (i.e. a non tapered tail/tuck would be a hard edge at the bitter end).
If you are also new to splicing... this HM line is single braid, 12 strand (there are others) and the easiest line to splice. its a good way to get started with splicing. I would have them do the end to end splice (taper) and do the eyesplice yourself (get some extra line to practice with if you are new..)
MN3

Let me add my 2 cents. Don't bother putting an eyesplice on the end. You will end up cutting it to the proper length after you sail it a couple of times. Don't worry about losing strength with knots (no disrespect Andrew)'cause it ain't going to matter. The stuff is so strong you could hang a tribe of cavemen with it, even if it were to loose 50% breaking strength. Tie the bitter end with a bowline and go sailing. Once you get the length right you can put the eyeslice on if you like. You can use the trimmed piece to practice you eyesplice with over and over until you get your confidence.
Let me add, the load on the bitter end that you will tie off or eyesplice is minimal, I repeat, it is an insignificant load. An added benefit is you can quickly remove the sheet for rinsing, drying, washing, storing, etc.
To put the knot nonsense in perspective, spin boats are knotting the spin bridals, as they are constantly being adjusted. The bridals are 1/8" HMPE and they do carry much more intense and significant loads.
Not calling you out Andrew, as knots and strenght are indeed important, but they don't really apply here.
Philip

andrewscott wrote:
I really want to move to a tapered main... but need to replace my 90' spin halyard with a tapered line first (as my current one burns holes in my spin every time)
Andrew, you might be in luck, if your current spin has a HMPE core you can taper it. I did it on a used spin halyard and liked it so much I used it. I can give you more details if you like. So easy a caveman can do it. . .
Philip

Thanks Philip ...
I am currently using 90' of xls (i think its Dacron jacket and polycore but unsure). I may strip the cover anyway.
Robbie D showed me how he strips and burys 5mm robline dingy control line (for his spin halyards) and i did it for my martingales (pole bridals)
MN3

Let me add, the load on the bitter end that you will tie off or eyesplice is minimal, I repeat, it is an insignificant load. An added benefit is you can quickly remove the sheet for rinsing, drying, washing, storing, etc.
Good point Philp, you are correct. Each line in the block has the same force, and that force is equal to what you have at the cleat. So if you can pull the line coming out of the block that is about the same force every line in the block has on it. The connections from the block to the crossbar and the boom are totally different then the force on each line in the block.
I was just thinking an eye splice would make a really clean connection that wouldn't come loose over time, but I see your point about likely having to trim to length the line once I use it. Guess I just need to check the knot periodically.
Scott
Hobie 18M in Chicago

andrewscott wrote: Thanks Philip ...
I am currently using 90' of xls (i think its Dacron jacket and polycore but unsure). I may strip the cover anyway.
milk back one end and inspect the core. If it has a good tight braid open it up and put a sample bury in it and see how it looks. Some cores are crap for burying that have a loose parallel braid. It's worth a look . . .
If you buy a new halyard you will only need about 55-60 feet. Endurabraid would work well and is reasonable $$.
Philip

its true you dont need to worry about the strenght of 4mm amsteel (around 1000lbs depending on which amsteel) but i still like an eyesplice at the end. it's only held to the blocks with a little becket and 1 pin.. not hard to remove if you want to wash your sheets.
and most important of all.. it looks cool!!!! (and no body will ever see it there if you dont point it out) but its cool!
MN3


If you buy a new halyard you will only need about 55-60 feet. Endurabraid would work well and is reasonable $$.
i am seriously considering going with 4mm robline racing sheets for my halyard.. no taper needed (dynema blend) and i have a friend with a discount... 🙂 but i will also look at Endurabraid
MN3

and most important of all.. it looks cool!!!! (and no body will ever see it there if you dont point it out) but its cool!
I had the same thought. As long as I was getting a custom tapered mainsheet I would be using for a long time, might as well spend the little extra for the cool factor. The fact it is technically a better connection is a bonus.
Scott
Hobie 18M in Chicago

If you are also new to splicing... this HM line is single braid, 12 strand (there are others) and the easiest line to splice. its a good way to get started with splicing. I would have them do the end to end splice (taper) and do the eyesplice yourself (get some extra line to practice with if you are new..)
Holy moly that looks complicated! Do you guys really do a lot of this tapering/spicing? Still always though provoking! I'll never look at ropes again the same way.
Larry Smith

smfinley wrote:
and most important of all.. it looks cool!!!! (and no body will ever see it there if you dont point it out) but its cool!
I had the same thought. As long as I was getting a custom tapered mainsheet I would be using for a long time, might as well spend the little extra for the cool factor. The fact it is technically a better connection is a bonus.
Scott, like I said before, you WILL trim to length, then you can add the eyesplice. It really is easy, . . . . and you will be . . . . COOL!
Philip

Andrew, regarding the issue with burning holes in the spin:
This is caused by the hard round covers on today's quality sheets, especially the popular double braids. It is when you pull hard that the round firm surface of the halyard pinches the spin between and against the hoop. So, how do we illuminate this problem. Two ways, one is with the douse technique, the second is to change the douse part of the halyard. The idea is to get rid of this hard firm round surface that is doing all the damage to the spin, which can be accomplished in many ways. In your case, you can fix this problem without replacing your halyard, if it is a double braid. How? Remove the core about 25-30 feet (for your boat) on the dousing end. This allows the cover to lay flat against the spin and hoop when dousing, rendering your burn problems a thing of the past. The added advantage is that when the spin is set in very light air, the dousing end of the spin is much lighter and has less effect on the shape of the spin.
If you have a stripable double braid now, rather than remove the core, just milk the cover back 25-30, bury the cover, and walla!, you now have a tapered spin halyard. Core for the head (less windage), cover only for the douse (lighter weight, no burns). So easy a caveman can do it!
So, with all the money you will save on a new 90 foot halyard, you can get that new tapered mainsheet and buy me a rummy.
Philip
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