Centre Back Stay Plus Runners

Centre Back Stay Plus Runners

Frasmar
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Frasmar
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Joined: May 11th, 2017, 7:30 pm

May 14th, 2017, 3:58 pm #1

Hi all. I realise there hasn't been a lot of recent posting on this forum, but hopefully people are still connected.

I just took the plunge and bought Rascal, a pretty little Evolution 26. She has a fractional rig. I think 3/4, as that is what it says on the sail bags. (Haven't sailed her yet as I have a few things to sort out first.). Spreaders are swept back. Mast is fairly far forward.

She has a conventional centre back stay connected to masthead - adjustable on a y split. But she also has runners which attach to the mast at the same height as forestay and to each corner at the stern. These would clearly impede the main sail, but not the boom.

Question is - are the runners optional and just for trimming with the central back stay being enough for structural stability? Or are they structural and therefore required to not lose the mast? The chain plates for the centre back stay are much more substantial than those for the runners. So I'm assuming the centre back stay is the primary structure and that it would be OK to strap the runners out of the way at the mast. But don't want that to be a costly or dangerous mistake!

If I do need to use the runners, that will be new for me. (Might be a bit of a pain because I want to be able to single hand.) I assume it's just a case of slackening off the leeward runner and tightening the windward on each tack?

Hopefully this message will be picked by someone who knows whether it's safe To sail without them :-)

Cheers,

Fraser
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Toroa Boat
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Joined: May 20th, 2009, 6:03 pm

May 14th, 2017, 9:01 pm #2

Hi Fraser

Congratulations on buying an Evolution 26. Aren't they pretty!

My boat, Toroa of Axe, also has the tall 3/4 fractional rig with running backstays, set up as you describe. As well as the foot of the mast being further forward than designed for the original masthead rig, the attachment point for the shrouds is also further aft. This rig is the most racy and it is light, flexible and tweaky. The mainsail is quite big for the size of boat and there's a lot of power up there. That's why it needs running backstays. They were quite common among racy boats late 70s, early 80s

I've raced quite a lot on the river Exe and have found that on the flat water of the river I don't need to use the runners, which helps for short tacking in light winds. Even with full main & spinnaker in a good breeze I don’t use them, and I have quite a lot of rig tension set up. The standing backstay to the masthead can be tensioned up to induce fore & aft bend and flatten the mainsail. But in these conditions the forestay goes a bit slack downwind!

At sea I use the runners all the time and the mast is very well behaved. I found in only moderate seas that if the runners are not used the mast 'pants' in waves. I would not want to go to windward or reach into waves (when the boat slams) without the runners tensioned.

I guess you could do away with the running backstays if you don't use the full power of the rig, particularly by reefing the main early, but I wouldn’t recommend it.

I was unfamiliar with runners when I bought Toroa of Axe and uncertain how to use them. The previous owner, who had the boat from new for 25 years, did some serous offshore racing in it in the 80s so I continued with his set up. The movement of the runners when not tensioned is influenced by two lengths of shock cord, which serve to get the leeward runner out of the way of the boom.

The first pulls the runners forward at the height of the spreaders. Each end is attached to a runner at spreader height and runs forward around the mast above the spreader roots. When a runner is tensioned, the shockcord pulls the untensioned, leeward, runner forward at that height.
The second length of shockcord runs through a small block attached to the standing backstay well above head height and is attached at each end to the lower end of the runner wire. This serves to lift the leeward runner sufficiently up and aft so it doesn’t foul the boom.

I could try to post some photos if this site still allows that.

God sailing
David
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Frasmar
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Frasmar
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Joined: May 11th, 2017, 7:30 pm

May 17th, 2017, 5:16 pm #3

Hi David,

Sorry I just saw your reply now. Many thanks for this. What you've written here is really informative. For the next while I will only be sailing in light and moderate conditions in the Tay estuary. Sounds like if what I'm doing isn't too full on I can get away without the runners, but keep them ready in case needed for stronger or choppier conditions.

I would be interested to see photos of the shock cord arrangement you have, to fully understand where the leeward runner sits and any interaction that has with the main sail (or not). If the forum image posting doesn't work, I could pm you my email address.

Again, many thanks for responding. That has helped to clear up a lot in my understanding.

Cheers,

Fraser
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wicked
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wicked
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Joined: June 18th, 2006, 10:39 am

October 14th, 2017, 6:49 am #4

Hello Fraser

If you have the swept back spreaders with the chain plates in the original position (i.e.a few inches behind the bulkhead) then you can get away without using the running backstays in moderate conditions or if the sea is fairly flat. However if you are racing, loading up the windward running backstay will tension up the forestay and you will point into wind much better.

On my evolution I have replaced the stainless steel running backstays with dynema ones with a hard eye at the bottom end - and just long enough to reach the bottom of the stays. This allows me to unclip them from the tackle and take them forward to tie off at the bottom of the stays when you don't want to use them. Works really well.

Many of the racier Evolutions have been modified to move the chain plates forward to the bulkhead and the spreaders angled further forward. If yours has had this mod then I suggest you should certainly use the runners.

The main issue to watch for is catching the slack runner on the boom in a violent gybe - which could possibly take the mast down. You should have a small eye on the backstay - about as high up as you can reach if you stand on the seat. Then a bungee clips to one runner, goes through the loop on the backstay, runs down the backstay to a small block above the tensioner, back up and out of the loop then clips to the other backstay. This will (should) pull the one that is not under load back and out of the way of the boom. You need the extra length of bungee down and back up the backstay in order that there is enough stretch for the slack runner when the boom is right out on a run.

If you want some photos drop me a PM

Dave

Evolution 26 - 'Wicked'


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