Lowers Replacement

Use this section to ask any questions over current class rules or to make suggestions over new rules that may be worthy of consideration.
George354
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Lowers Replacement

Postby George354 » Mon Aug 10, 2015 12:56 pm

Afternoon all,

So the rules state:

(4) Standing rigging may be replaced and shall comply with the
following:
(i) Construction shall be 1 x 19 stainless steel wire rope.
(ii) The forestay, shrouds and lower shrouds shall be of a
minimum diameter of 2.9mm and a maximum diameter of
3.1mm.
(iii) Wire terminals shall be commercially available.

Following the rules to the letter this therefore does not allow me to replace my lowers with a set of 2.5mm lowers. Correct?

Cheers,

George

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Re: Lowers Replacement

Postby Rick » Mon Aug 10, 2015 2:56 pm

I'm no rules expert but I'd say 2.5 is not between 2.9 & 3.1 ...

However, why would you want to skimp on this anyway with 2.5mm wire; in what way would they be better?

The standard was increased as there were a few examples of breakage.
Rick Perkins. GBR

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paul manning
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Re: Lowers Replacement

Postby paul manning » Mon Aug 10, 2015 3:06 pm

For reference, if a product was class legal at the time of supply, it remains class legal.

So a 2.5mm lower shroud was class legal but to replace it would now require 3.0mm.
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George354
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Re: Lowers Replacement

Postby George354 » Mon Aug 10, 2015 4:49 pm

The main reason for not wanting to change is after having finally got somewhere near proper rig set up I don't fancy jeopardising it by going and chucking another variable into the mix.

Surely loos gauge tension then becomes a dark art of converting 2.5mm lowers tension numbers to 3mm? And there must now be greater sensitivity on kicker control due to less give from the lowers and therefore greater lower mast stability.

Anyone got any helpful hints?? Conversion table or something similar...

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paul manning
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Re: Lowers Replacement

Postby paul manning » Mon Aug 10, 2015 5:25 pm

I believe you can draw them together on one graph and then measure off the two numbers to compare.

Within the lower shroud range I then get the following but I'm not sure what the effect is of dropping off the scale. However, assuming you are reading say 11 on 2.5mm wire, then you'd be looking for just over 13 for 3.0mm.

2.5mm
9 = 52
10 = 58
11 = 62
12 = 67

3.0mm
9 = 40
10 = 45
11 = 50
12 = 55
13 = 60
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Re: Lowers Replacement

Postby George354 » Mon Aug 10, 2015 8:39 pm

Cheers Paul

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Re: Lowers Replacement

Postby Rick » Mon Aug 10, 2015 8:42 pm

George354 wrote:The main reason for not wanting to change is after having finally got somewhere near proper rig set up I don't fancy jeopardising it by going and chucking another variable into the mix.

Surely loos gauge tension then becomes a dark art of converting 2.5mm lowers tension numbers to 3mm? And there must now be greater sensitivity on kicker control due to less give from the lowers and therefore greater lower mast stability.

Anyone got any helpful hints?? Conversion table or something similar...


If you set a 3mm lower to have the same tension as a 2.5mm one then you will be fine.

The difference in elasticity in the short section of the lower will not be noticeable but the improved breaking strain will be most welcome.

If you are 11 on a 2.5mm lower then you will need 13 and a bit on a 3mm lower ... although the loose gauge is pretty poor at those sort of tensions anyway. I always recommend a Harken RigTune Pro for lowers.
Rick Perkins. GBR


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