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?
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Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
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8:1 Harken 57mm ratch-matic blocks
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Posted: Dec 01, 2009 - 10:41 PM
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Posted: Dec 02, 2009 - 12:27 AM
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.
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Rob
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Posted: Dec 02, 2009 - 12:30 AM
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.
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Philip
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Posted: Dec 02, 2009 - 09:43 AM
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 -
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Posted: Dec 02, 2009 - 10:21 AM
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
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Dec 02, 2009 - 10:37 AM
Also look at Salsa line. it is VERY soft, decent price, made in the USA (i think) and cleatable (unlike regular dyneema). -
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Posted: Dec 02, 2009 - 12:13 PM
So does the robline racing sheet not cleat well? I am looking for a good main sheet that does cleat. Sounds like I will go with the 3/8 now just need to determine what type and brand.
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Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
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Posted: Dec 02, 2009 - 12:48 PM
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.
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Rob
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Posted: Dec 02, 2009 - 02:39 PM
what technique do you use to taper from 10mm to 6.5mm (1/4") or do you purchase it? -
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Posted: Dec 02, 2009 - 03:33 PM
Scott,
you can also consider a strippable double braid made for the purpose, like Endurabraid. It also will work great. All you have to do is strip the 10 feet of cover and bury it. So easy a caveman can do it. . . .
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Philip
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Posted: Dec 02, 2009 - 03:37 PM
dont foget a lock stich with stipped / buried cover
Can cave men thread a needle with them big Barney Rubble thumbs? -
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Posted: Dec 02, 2009 - 03:41 PM
personally, I whip it. That transition point turns through the blocks continuously. I do not whip any other buries, though.
edited by: mummp, Dec 02, 2009 - 02:53 PM
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Philip
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Posted: Dec 02, 2009 - 06:37 PM
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).
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Dec 02, 2009 - 11:09 PM
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.
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.
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Rob
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Posted: Dec 02, 2009 - 11:48 PM
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.
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Dec 03, 2009 - 09:42 AM
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) -
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Posted: Dec 03, 2009 - 02:01 PM
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.
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Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
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Posted: Dec 03, 2009 - 02:35 PM
Yes
Yup, for a fee
exactly
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..) -
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Posted: Dec 03, 2009 - 03:17 PM
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.
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Philip
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Posted: Dec 03, 2009 - 03:26 PM
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. . .
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Philip
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