Hobie Cat Forums

Many people have written about excessive weather helm with their TI's. I just spent about 2.5.hours on the water looking for it on mine and could not find it on any point of sail even when I would intentionally mal adjust my sail.

Forecast said winds out of the east at 9 with gusts to 27. I don't think the gusts got above about 20. I would line my boat up with either a fixed marker in the water or a boat that was anchored, trim the sail and let go of the rudder doing about 4 knots. The wind would gust and the boat would get up to about 6.8 knots at which time the boat would have fallen off enough to affect the sail trim and I would have to tweak the rudder to turn the boat closer to the wind. This is a symptom of lee helm.

The only time the boat would turn into the wind was when the wind would die. This makes sense because the slight lee helm I have requires the rudder to be turned slightly into the wind.

On the way home I had what might be a BFO (I will let you guess what that is. You can email me directly if your answer is not fit for this publication. I'm a sailor and tend to talk like one.). In almost all the videos and write-ups I see and read the mirage drives are installed. I carry a drive for emergencies but normally don't sail with it installed.

Has anyone had a problem with weather helm with their drives out? This could be an interesting discovery.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

Depends on the speed of the wind, angle of the hull and angle of sail for me.

If we've got serious wind and are close hauled, we generally will have weather helm until Cindy gets onto the upwind trampoline - then the helm becomes a lot more neutral and manageable. If the winds are more moderate - or if I ease the point of sail - the weather helm diminishes. But close hauled in solid winds with any amount of heeling will produce weather helm for me that will pop the rudder right out of the groove.

The same is true for me if I'm solo sailing with the blanks in place; moderate winds and lower angles of sail result in neutral helm, but stiff winds and close hauled will reliably result in weather helm.

Also, there can be some serious side slippage as well, even with the centerboard fully deployed.

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Mitch

2010 Tandem Island
2010 Revolution
Chesapeake Bay and Eastern Shore

My sailing blog
Our sailing videos

Mitch,

The rudder popping out is not being caused by weather helm. I bolt mine in place so it can't pop up and since I don't have any tension on the "Down" line the rudder is very smooth and easy to turn.

The big question is do you have your Mirage drives in when you sail?

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

Rather surprised you haven't experienced weather helm Jerry!

In stronger winds, when close-hauled, the mast bends considerably. This shifts CE further aft. Also, CLR moves forward as the ama submerges more. This results in weather helm.

Having the drives in can affect the CLR to a degree, especially if in the vertical position.

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Cheers, Max ● TI: the "Yella Terra" ● Website: www.MadYakker.com ● YouTube: madyakkermax

I tested a TI out in Kailua Bay on a typical day. Probably was averaging 14-15kt winds definitely had some weather helm when close hauled. After a short while sailing close hauled the rudder did pop loose and I had to stop and pull the rudder up and then re-seat it back down. Not saying it's related to weather helm.

dosjers, help me.
Why would weather helm not be a factor in twisting and raising the rudder, which it wants to do by design? When not locked down, they are just held in place my wet spectra line and cleats. It is supposed to give way and pop at some point.

I would expect a locked rudder to track better and feel more balanced than an unlocked (or poorly cleated one). At least on one side.

And I would expect helm (or lee) forces to exert additional rotation on the T&S mechanism. Along with current and swells.

I don't pretend to know the math involved here. (That's why we have Max around).

But if you repeated your experiment, once with the rudder cleated, and then with it bolted in place, the results might prove interesting.

By all means, test with and without the Mirage drives too. This was discussed at length, related to the AI.

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"You can avoid reality, but you cannot avoid the consequences of avoiding reality."
- Ayn Rand

I'm with Max on this one. And yes, it happens with the drives in or out, with or without the drive blanks in place.

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Mitch

2010 Tandem Island
2010 Revolution
Chesapeake Bay and Eastern Shore

My sailing blog
Our sailing videos

Mate, observations leads to theories, and then maths (such as in physics) finds the explanations, and so we have science. But apart from mega genius's like Einstein, it does usually begin with experiences.

Actually, aside from the CE moving aft, and CLR moving forward, there is a much bigger effect created by the craft heeling, and the mast also bending to leeward - a turning moment. Kayaking Bob posted a great pic of an Island ahead of him in strong winds, and you could easily see how far the CE had shifted to leeward.

This easily overpowers the drag effect of the leeward ama... imagine a twin engine aircraft, when only one engine has power (in our case, to leeward) - a very strong turning force.

Using your super models as ballast , you decrease the heeling angle, and thus also this turning force, so less weather helm. Just as Mitch has observed. So in strong winds, to keep weather helm to acceptable limits and maintain control whilst carrying a lot of sail, keep loading up the weather tramp with models.

Of course, if the wind dies down, or you turn downwind, you'll need to throw them overboard!

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Cheers, Max ● TI: the "Yella Terra" ● Website: www.MadYakker.com ● YouTube: madyakkermax

Ok I give up. What I was trying to find out is whether or not anybody experienced the problem with weather helm when sailing with their drive out and I still don't know. I guess I will have to break down and install them the next time I sail.

The reason I said the rudder popping out was not caused by weather helm is because the reason the rudder pops up is because of poor design which will be rectified soon, we all hope. Before I started bolting my rudder down I experienced considerable lee helm when sailing in high winds with my sail reefed.

Max used an analogy of a twin engine plane with only the lee engine giving power. He says the plane will turn to weather which I agree. Now, take this one step further and put the lee wing tip in the water and I bet the plane turns off the wind and crashes due to the excessive force from the water.

Someone mentioned an AI having weather helm and I agree. I have seen and felt it many times in an AI I we are talking only about the TI's having lee helm.

After all that, I guess I'm not giving up yet, I'm still interested in finding out how many of you have experienced weather helm with both drives not installed.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

Jerry, were you sailing solo from the aft seat when you experienced lee helm?

Max,

Yes and right now I weigh about 230 lbs.

I was sailing on Saturday with my son in the front seat. He weighs about the same as me and did not have any weather helm but the winds were not as strong.

In the past I had my wife in the front seat who is considerably lighter and in winds that required us to reef the sail I had some lee helm. That day the spray got the top of her head wet.

It doesn't make any sense that when the wind picks up my boat wants to turn away from the wind and all the rest want to turn into the wind. That's why I'm wondering if the drives are the difference.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

When I sailed solo, rear seat, it lifted the bow considerably, especially when underway. The vid showed the bow out as far as the mast. I've seen the same on another couple of vids. This moves the CLR well aft, and could be a cause of lee helm.

[edit] Forgot to mention I had only 5-10 knot winds, and neither weather nor lee helm, but wind was too light to see how the TI would handle. [/edit]

Next time you get out, try the forward seat, especially on your own, and with some wind - you should get considerable weather helm.

The TI is, I think, fairly susceptible to loading balance. I'm even thinking of some ballast (!!!) when sailing solo in good winds.

Max,

Have you experienced the weather helm problem with both your mirage drives out?

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

Yep. Haven't noticed much difference with drives in or out.

But note that I'm still sailing mostly in the forward seat until I get an aft furling cleat organised - I use it a fair bit when the wind picks up.

I agree that there is lee helm in a TI with the drives out. I sail from the front seat with my wife in the rear seat because I've noticed that the TI is sensitive to weight distribution and because I want to be able to raise and lower the center board quickly in our shallow tidal estuary. In 10 to 12 knot breezes and sheltered water, the TI definitely has a slight lee helm. When the wind speed gets higher and or there is more wave action, there is a shift to weather helm. Indeed, the degree of weather helm is the primary factor in my deciding to reef. Since I sail with the drives out unless there is a reason to have them in (drifting conditions or wind from where I want to go), I can't comment on whether the drives affect the amount of helm pressure. I assume there has to be an effect, but I don't know what it is.

PBurling