J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment backstay

A couple of questions regarding the backstay: 1. To the best of my knowledge the backstay lends no structural support to a 7/8's fractional rig with swept back spreaders albeit for inducing mast bend for main sail trim. 2. Is approx. 6" mast bend with the backstay adjuster all the way down normal? 3. Are modifcations to the backstay adjuster subject to class rules ie. replacing the 3/16" stainless with amsteel and replacing blocks?

1. To the best of my knowledge the backstay lends no structural support to a 7/8's fractional rig with swept back spreaders albeit for inducing mast bend for main sail trim.

Mostly true - it does prevent the mast from rotating forward with forces from the headsail and spinnaker.

2. Is approx. 6" mast bend with the backstay adjuster all the way down normal?

That sounds about right

3. Are modifcations to the backstay adjuster subject to class rules ie. replacing the 3/16" stainless with amsteel and replacing blocks?

You can't replace it with Amsteel under class rules. You can use whatever purchase system you want with the "pincher" on the backstay. Hydraulic cylinders are not legal, nor are direct connected purchase adjustments to shorten the backstay.

One thing you can do is shorten the backstay if it should need it. Often, when you go to max rake, the backstay has a lot of play, even with the turnbuckles tightened.

I was looking at backstay configurations and am thinking about doing it little differently than the standard J30 set up.

Do you have to use the stainless triangle pincher per class rules? or can you attach a block directly to the end of the backstay, run wire through it with one end of the wire fixed to one corner of the transon, on the other end of this wire attach another wire block, then run wire through that block from the other side of the transom, to your standard-purchase rope block and tackle and back down to a pad eye.

This configuration looks ligher and faster to take adjustment, plus you can move the pad eye outboard toward to one of the transom corners to keep things out of the way and have better angles for runnign the line forward in the cockpit.

I have seen this on some J30's and J27's.

Paul,

The backstay arrangement was discussed at the 2008 BOG meeting. Bottom line is that the changes you propose are not considered class legal. You can read about it at this link. See paragraph 4 with the explanation.

any suggestions on the better way to accomplish this? Go to the top of the mast, the bottom of the single stay, or shorten the two tail ends?

So OK ... I never considered the J30 to have swept back spreaders. Say like the modern day hunters. This concept changes my thinking seriously re my use of roller furling and trying to get the sag out by tightening the backstay.

Actually I should be releasing the backstay to remove forestay sag?

Today I wedged the mast to the back of the deck hole ... actually it was there anyway but I put wedges in to lock it in place..

By the way ... arrived Naples Sun. low 90s, sunny, on shore breeze at 10-12 --- kicks in around 1. same Mon., same today, same set for Wed, Thur, and Fri. I have found my summer we didn't get in Newport this year.

The existing backstay adjuster works fine, but you do want double ended controls led somewhere near the traveler. It's rare to see a race boat with the original fiddle block and cleat on the transom but we did a couple early NA's that way.

These days up to 10 knots we sail with the backstay slack, loose enough for the main to gybe with just a flick on the backstay if the top batten catches. The original spec is 38'2" for the upper backstay, so measure before you cut. The only boat I've ever done this to was hull #1, Warwhoop, which we used as a loaner in the 1988 Midwinters. Remove the upper backstay from the mast crane, cut and swage a new eye at the top—it's probably cheaper replacing the fork at the bottom.


From 10-15 take the slack out so the rig doesn't bounce in the chop. At 15+, when dropping the traveler isn't enough, progressively tighten the backstay to open the leach and depower the main. If we expect to see 15+ all day, we tighten the turnbuckles to take out the slack. The adjuster is more powerful near the top of triangle. I've not convinced the backstay does much to tighten the forestay upwind, but downwind in a blow (25-40) a bit of backstay helps keep jib luff from bouncing around. And the rig onboard.

a quick attach fork can be installed at the bottom for less than $25 eliminating the need to climb the mast. I've gone the full route to double ended line led to traveller back to the original much simpler configuration which I prefer. I don't race.....