Genoa sheet size?

[Trop Cher]

Hi,

I'm looking to replace the genoa sheets on my new to me boat but what with? The boat is 12 metres with a 140% genoa, the present sheets appear to be too large, certain for the self tailing winches. What would I be best using and what size?

Thanks.

 

[sailorman]

Hi,

I'm looking to replace the genoa sheets on my new to me boat but what with? The boat is 12 metres with a 140% genoa, the present sheets appear to be too large, certain for the self tailing winches. What would I be best using and what size?

Thanks.

16m/m

 

[Trop Cher]

Wow, that was fast!
Thanks

 

[Tranona]

Good sizing information on Jimmy Green website. Suggests 14mm. Would not need to be bigger than 16mm, but depends on your fittings and winches.

 

[wklein]

12mm would be absolutely fine, no sense in going bigger than necessary, i don't find 14mm easier to handle than 12mm

 

[grumpy_o_g]

Good sizing information on Jimmy Green website. Suggests 14mm. Would not need to be bigger than 16mm, but depends on your fittings and winches.

I was just thinking that. How do you know what size the winch takes? Is there a rule to follow?

 

[Tranona]

Think you need to be able to get at least 3 turns on, probably 4, but the big constraint would be the jaws of the self tailing top.

 

[charles_reed]

As already pointed out, the sizing is dictated, 1st by the jaws of the self-tailer, 2nd by the size which is easily handled. Both are best done by on-site evaluation.
I'd think 12mm will probably be ideal - 16mm is OK for anchor rode but totally impractical for sheets.
I use 12mm on my 150% 30m2 genoa and 10mm on my 69m2 spinnaker and genniker.
Both work perfectly in the Enkes/Harken self-tailing winches.
Apart from the cost consideration, the smaller the rope diameter the more easily it runs through blocks - I use 10mm spectra on my mainsheet for that reason.

 

[LONG_KEELER]

easily it runs through blocks - I use 10mm spectra on my mainsheet for that reason.

Just wondering what spectra is like on the hands Charles.

Have tended to use double braid over the years.

I like the idea of lighter sheets to pull the genoa round in lighter winds.

 

[sailorman]

Just wondering what spectra is like on the hands Charles.

Have tended to use double braid over the years.

I like the idea of lighter sheets to pull the genoa round in lighter winds.

it is not as flexible as matt braid on braid, ok for halyards but i wouldnt use it

 

[charles_reed]

Just wondering what spectra is like on the hands Charles.

Have tended to use double braid over the years.

I like the idea of lighter sheets to pull the genoa round in lighter winds.

It takes longer to "settle" than standard polyester braid on braid, but is no better and no worse to handle.
As to relative flexibilty there is absolutely no difference, long-term between the two. I started using Dyneema in 1997 and have replaced all my halyards over time.
There are two grades of outer braid, one for use with jammers (usually termed racing or hard), and the other referred to as "cruising". The latter is the one I have used, out of respect for pocket rather than hands.
Though not quite as strong or as stretch-resistant as Vectran Spectra/Dyneema is more UV resistant and quite strong enough. I also use it for life-rails rather than coated wire weight/diameter far stronger than coated SS wire and gives enough to avoid cracked ribs if you get thrown against it.
It's certainly a vast improvement over Kevlar with its sudden fatigue failure and high rate of UV degradation.

 

[lw395]

I can't see the need for dyneema or spectra etc for sheets, apart from where the kite sheet is also a guy.
A few % stretch in a gust is often a good thing for other sheets, although it can result in chafe if you are on the same point of sail for days on end.
The size that works best in the winch also depends on the stiffness of the rope, a soft rope will often grip better in self-tailers.