J/30 Class Association Forums J/30 Forum One Design Class Rules Mast Step Postion

The advantage of threaded inserts would be to reduce contact between the screws and the mast step? Would that still work for a step with adjustment slots?

From personal experience it took time, penetrating oil, and an impact driver to loosen the screws. Even with patience it tore up the screw heads. I replaced them with stainless hex head cap screws thinking that would make it easier next time using a socket wrench. Not sure now based on this discussion if that was the best choice but I have no plans to move not that the step is where it belongs. I did have to tighten the step soon after when the mast it slipped aft during a daylong spinnaker run in heavy air.

So OK ... is this what you guys are talking about... and is this good or bad what you see here???? This hasn't been touched since 1984.

Vic. That is legal per class rules:

5.7.3 Position of the mast shall be fixed at the deck 3505 mm plus or minus 13 mm from stemhead tip to the front edge of the mast. And it shall be permanently fixed to an immovable mast step so that the forward edge of the mast is not less than 25 mm aft of the forward vertical face of the molded step in the sole liner.

You are more than 25 mm aft. Effectively this moves the top of the mast forward. Not optimal tune. Read comments in this thread

this may explain why I can't get to legal max on forestay.
I've always hated light air sailing and this weekend we had 4-9 wind with 3 races where I was not keeping up with boats I had before i changed the roller this season. It currently has too much sag.

Temporarily I will just zonk the forestay a bit shorter to tighten up the sag, which seems to be "enhanced" with the weight of the roller furling. I am currently longer than the old roller but will return to that measurement if not a bit shorter to get more sag out of the forestay. next time i have the mast out will modify.

This may also explain the severe backstay/top batten problem I've had with new mains.

This sound like a workable plan?

Back to rules for a moment
5.7.3 Position of the mast shall be fixed at the deck 3505 mm plus or minus 13 mm from stemhead tip to the front edge of the mast. And it shall be permanently fixed to an immovable mast step so that the forward edge of the mast is not less than 25 mm aft of the forward vertical face of the molded step in the sole liner.

Since I don't block my mast at the partners,one could argue my mast is not fixed at the deck. Is it class legal not to block the mast at the deck?

Aaah the dreaded weather helm ....
If you haven't viewed Kid Peel

zip to the start of the close haul segment where 11 year old William is operating at nearly no weather helm running around 5.7 +kts.

It would be really interesting to see ,using a fish scale say for example, just how many pounds is required to point optimally under good wind conditions runing around 5.5kts.

I add this into the discussion as there have been comments that the J30 is not a kid boat and is tiring to sail close haul for most gals. Are we are talking about a very narrow tuning/wind-speed range? that may be related to mast step offset? {also consider that 505 has a modified rudder to somewhat offset weather helm}

later this week Brian J30 #22 and I will be shortening the forestay perhaps as much as 1.5 in. to get some of the wobble out of the forestay. Notice I am not saying sag, but wobble.

we will do the whole thing with back stay and shrouds off. I'm thinking tuning the lowers first to establish a "fixed" point in regard to the forestay ... In othe rwords basically tuning to a forestay length geared to eliminating wobble but a reasonably straight mast.

We're stepping a bit outside the perameters of discussing rules so someone may way push back - regardless.
Weather helm and balanced helm need to be separated for a minute.
Moving the center of effort fore or aft will induce a need to steer with either lee or weather helm, (in the sense that the tiller/rudder will need to offset the tendancy of the boat to want to fall off or steer to weather. A "balance" of the helm will determine the load on the helm but not the angle of attack of the rudder. By modifying your rudder you have balanced it but I'm guessing that in a 20k blow, with #1 and a full main trimmed in tight, you'd still have "weather" helm
I'm of the beleif that the helm should be pretty neutral and thus adjusting crew weight and sail trim (as in depowering the rig) is faster than sailing with "weather helm"

Folks - this is a great discussion. Between the rules and the functional review of how the step, partners, etc. changes affect the way the rig sets up, it's a great overview of how to optimize the boat's performance.

Back when Bill and Dave asked for feedback, one of the things I suggested were more "How-To" articles. Often, great ideas and knowledge are buried in not just one thread but even cross-linked between multiple threads. For a newb visiting the site trying to figure things out, find good guidance, etc. it's not terribly easy to find what's needed to get the boat and rig in tune (and in optimized class conformance). Same for other topics.

It would be great to see folks, as they do these projects, take the content in the threads, their own pics, measurements, and whatnot, and create one document that highlights the process. That would help bring the entire class up to speed, demystify some of the more obscure projects, and help establish authority of a great community and class across all sailing communities.

Some sample topics that jump to mind include:
- Updating the mainsheet to gross/fine trim
- Updating the backstay adjustment controls
- Installing a boomvang/kicker
- Installing new halyard stoppers
- Replacing the standard hatches
- Rebuilding the original Barient winches
- Replacing the fixed portlights

There are some great sites (like Bill's!) that feature some of this content but it would be great to either host some of it on the J30.org site or at least develop more organized links to it.

Creating a new forum post is likely not the best mechanism. What's the best way to create a document like this - with pics - that can then be added to the repository of How-To documents on the site?

Thanks! - Jeff

In order to get the best up wind performance you want to have the max straight rake in the rig this is achived by have the mast step at min setting (ie as far forward as possible) and the mast as far aft at the deck (mine is set with spar tite) and yes it has to be fixed for the N/A's.

Then you can set the forestay for max lenght. Back stay should be totally loose. With those settings you can follow the tuning guide from your sail maker. I have settings for light (< 10 knots true) medium (8-14) and heavy 14 and up

I only adjust the shrouds not the head stay

That said when we are hard on the wind going up hill the helm is totally balanced (two finger driving) up thru about 13-14 knots

After that the amount of mainsheet trim and travel becomes key to keeping the boat flat and balanced I have never had to two hand the boat when hard on the wind Reaching is a different matter that can be real work

Hope this helps

I kind of like the give and take here, even the occasional differences of opinion. This being a volunteer, underfunded, and participatory organization the 'do-it-yourself' aspect of the forum helps reduce the need for a moderator or maintenance. If you want something just ask. Anyway back to the rules...