[Rhodes22-list] IMF "Reefing"

Sun Feb 18 11:29:10 EST 2007

Wally,

There are a lot of newbies currently on the list trying to figure out 
how to configure their boats. Most of them do not seem to possess your 
level of sophistication. I know what you mean, but I don't think they 
necessarily do.

In light air, when my wife is not on board, I also sit on the lee side 
to create heel and go faster. I believe this is because there is less 
wetted surface when you heel an r-22. But I believe there is also a 
shorter waterline than there is on a bow-heavy upright r-22 so your top 
speed in winds capable of driving you at hull speed is less when heeled. 
I don't think you can plane when heeled. Give me some good wind and I 
can plane upright at more than the hull speed of the boat every time.

Jay -- are you paying attention? You always have enough wind. Father's 
Day 07? (If you try this out before I get there you can't use your 
paddle wheel speedometer to determine boat speed--we must use a GPS. The 
boat doesn't have enough power to go through the water at more than 6.25 
kph, but it can go over land at 7-11 kph.

Bill Effros

TN Rhodey wrote:
> Bill, First as you know I do like IMF.... My original post stated you 
> may have to reef sooner with IMF than standard. I wasn't really 
> commenting about reefing sail shape or configurations.
>
> One thing you need to consider is the cut of the sails unfurled and/or 
> reefed. This is just important as the size. To my eye it looks like 
> the belly on most IMF sails (ours included) is higher than standard 
> main and perhaps a little further aft. With standard main you can 
> further tweak with downhaul, halyard, and cunningham controls.
>
> Also my boat likes a little heel and in light air I sit on lee side to 
> create heel....and I go faster.
>
> Wally
>
>> From: Bill Effros <bill at effros.com>
>> Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>> To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>> Subject: Re: [Rhodes22-list] IMF "Reefing"
>> Date: Sat, 17 Feb 2007 10:51:09 -0500
>>
>> Jim,
>>
>> I think you must add the optimal heeling angle to your equations.
>>
>> Since the R-22 is designed for 0 degree angle of heel, none of the 
>> weight aloft matters to the angle of heel, whether a standard or an 
>> IMF is deployed.
>>
>> With a 175 Genny the boat has so much more sail than it needs that it 
>> can always reach hull speed in 10 kts. of wind--the only significant 
>> variable is the skill of the captain.
>>
>> At 0-5 degrees of heel it is possible to bring the boat on plane. As 
>> the heel becomes greater I don't believe you can make the boat 
>> plane--at least I've never heard of anyone doing it while heeled over.
>>
>> Bill Effros
>>
>> Jim Connolly wrote:
>>> It seems to me that the difference between IMF and conventional from a
>>> weight distribution standpoint is two fold:
>>>
>>> 1. The furling tube which is negligible and the weight of the mast
>>> extrusion, heavier than standard. Both of these are fixed weights 
>>> (fixed
>>> height above deck with the mast raised in sailing position) and can be
>>> approximated by a weight "x" at the midpoint of the mast (i.e., 
>>> center of
>>> gravity or CG).
>>>
>>> 2. The weight of the sail (less than conventional, because it is 
>>> smaller).
>>> Since it reefs and furls on a vertical roller, the CG of the sail 
>>> also stays
>>> at the same height above the deck. The center of effort (CE) of the 
>>> furling
>>> sail will move down and forward as the sail rolls into the mast.
>>>
>>> Net effect, furling the IMF lowers the center of effort and not the 
>>> center
>>> of gravity of the mast and sail combination, while furling the 
>>> conventional
>>> sail lowers both the CG and CE. The CG of the conventional mast/sail
>>> assembly is lowered by the weight of the sail, which is not likely a
>>> significant part of the whole.
>>>
>>> It seems then to come down to the additional weight of the IMF 
>>> assembly with
>>> sail vs. the conventional mast and sail. I don't know this, but I am 
>>> sure
>>> somebody here does. Likely windage of the thicker mast extrusion 
>>> might be a
>>> factor in some wind conditions.
>>>
>>> For me, convenience trumps all.
>>>
>>> Jim Connolly
>>> s/v Inisheer
>>> '85 recycled '03
>>>
>>> -----Original Message-----
>>> From: rhodes22-list-bounces at rhodes22.org
>>> [mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of Bill Effros
>>> Sent: Saturday, February 17, 2007 9:55 AM
>>> To: The Rhodes 22 mail list
>>> Subject: [Rhodes22-list] IMF "Reefing"
>>>
>>> Wally,
>>>
>>> Comparing "reefing" on standard sails vs. IMF sails is very hard to 
>>> do when
>>> discussing among sailors some of whom have never even seen an IMF.
>>>
>>> "Reef Points" result in noticeable changes in sail size. The IMF is
>>> infinitely adjustable. I often adjust my sail in increments of 5% of 
>>> total
>>> sail size. I suspect most IMF sailors change the size of their sails 
>>> instead
>>> of using the traveler. We don't think of it as "reefing" -- it is an 
>>> adjustment the sailor can quickly make in response to changing
>>> conditions.
>>>
>>> The extra weight of the mast is insignificant. Remember that your 
>>> sail is
>>> larger, adding weight aloft compared to the smaller IMF sail. But, 
>>> since the
>>> boat is designed to be sailed upright, and can easily be trimmed to 
>>> sail
>>> upright, the difference in performance due to weight is probably no 
>>> greater
>>> in an IMF boat than the difference of carrying an extra bottle of 
>>> rum. Or
>>> not.
>>>
>>> I carry my extra sail on the Genoa instead of the main sail. Both are
>>> infinitely adjustable while single handing. When conditions change, 
>>> I change
>>> the set of my sails, all by myself, so easily that even a lazy 
>>> sailor will
>>> do it.
>>>
>>> I think the biggest surprise about the IMF is how well it works
>>> mechanically. The sail and mast are made for each other. There is no
>>> compromise here, and it is easy to extend and retract the sail under 
>>> any
>>> conditions. My wife enjoys doing it.
>>>
>>> Our harbor is busy on weekends with a very narrow neck, rocks all 
>>> over the
>>> place, and a 10 foot tidal variation every 6 hours. It is 
>>> irresponsible to
>>> sail into the harbor if you've got a motor, and most experienced 
>>> larger boat
>>> sailors take their sails down just outside the neck, and motor to their
>>> moorings. We turn on the motor and don't even stop while we retract our
>>> sails. When my wife sees other wives trying to control flopping 
>>> sails inside
>>> lazy jacks she shakes her head in disbelief. When other wives see my 
>>> wife
>>> roll up our sail they ask their husbands why they don't have sails like
>>> ours.
>>>
>>> Bill Effros
>>>
>>>
>>>
>>>
>>>
>>> TN Rhodey wrote:
>>>
>>>> Bill,
>>>>
>>>> Well I may be wrong here .....I guess it would depend upon how much 
>>>> smaller the sail is verses the extra weight of mast. Way back when 
>>>> (on the sailnet list) there was discussion about this. In my 
>>>> opinion even if the mast weighed the same you still might need to 
>>>> reef sooner with IMF. Pure speculation on my part and I will admit 
>>>> I may be totally wrong.
>>>>
>>>> The R22 is small enough to be quite sensitive to subtle changes in 
>>>> weight and trim adjustments. You pay a price with IMF in mast 
>>>> weight, sail cut, no downhaul, no cunnungham, no battens (except 
>>>> for the new rev). If you know how to use all these controls you can 
>>>> create a much flatter sail. You would be surprised at the 
>>>> difference adding a vang made even with IMF. I could still flatten 
>>>> the sail enough to make a big difference ...sailing much flatter, 
>>>> fast, and higher into the wind.
>>>>
>>>> Everything is a trade off and for me the pros for IMF are well 
>>>> worth any cons.
>>>>
>>>>
>>>> Wally
>>>>
>>>>
>>>>
>>>>> From: Bill Effros <bill at effros.com>
>>>>> Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>>>>> To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>>>>> Subject: Re: [Rhodes22-list] Harken Lazy Jack
>>>>> Date: Fri, 16 Feb 2007 09:02:30 -0500
>>>>>
>>>>> Wally,
>>>>>
>>>>> Why would a smaller sail need to reef sooner?
>>>>>
>>>>> Bill Effros
>>>>>
>>>>> TN Rhodey wrote:
>>>>>
>>>>>> Joe, There are some performance trade offs with IMF. The sail is 
>>>>>> smaller and I would think an IMF R22 would need to reef sooner 
>>>>>> but I am just guessing. That extra weight aloft must have some 
>>>>>> effect on balance.
>>>>>>
>>>>>> Wally
>>>>>>
>>>>>>
>>>>>>> From: Joseph Hadzima <josef508 at yahoo.com>
>>>>>>> Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>>>>>>> To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>>>>>>> Subject: Re: [Rhodes22-list] Harken Lazy Jack
>>>>>>> Date: Thu, 15 Feb 2007 16:45:37 -0800 (PST)
>>>>>>>
>>>>>>> I've seen some other cool sail systems, some with sail covers so 
>>>>>>> you only need to zip it closed. Several replace the slot in the 
>>>>>>> main with a track system so even a kid could hoist the main, and 
>>>>>>> it drops into right into the sail cover.
>>>>>>>
>>>>>>> A BIG advantage of the IMF (I believe) is the unlimited reef 
>>>>>>> points. Another is that is remains protected in the mast during 
>>>>>>> transport.
>>>>>>>
>>>>>>> I've only heard one mild complaint that the IMF mast is thicker, 
>>>>>>> and thus hinders pointing performance a little, but like Stan 
>>>>>>> says there are trade-offs ... unlimited easy to set reef points, 
>>>>>>> or slightly better pointing with the possibility you'd need to 
>>>>>>> bring down the main completely because you couldn't depower enough.
>>>>>>>
>>>>>>>
>>>>>>> And I only had a minor problem with lazy Jacks where one of the 
>>>>>>> lines got wrapped around part of the sail, and we had to lower 
>>>>>>> and raise it again. But this was aboard a 65 foot Schooner with 
>>>>>>> gaft. So it was a little more trouble than if it was a Rhodes 
>>>>>>> with lazy jacks :-)
>>>>>>>
>>>>>>> Speaking of the A28 video ... I like the piston powered Hoyt Jib 
>>>>>>> boom for down wind sailing .. very nice feature.
>>>>>>> Notice it's a working Jib and NOT 175 gennoa!
>>>>>>>
>>>>>>>
>>>>>>> --- "Michael D. Weisner" <mweisner at ebsmed.com> wrote:
>>>>>>>
>>>>>>>
>>>>>>>> While viewing the AE28 video, I was impressed with the ease 
>>>>>>>> with which the owner was handling the main. He was using a 
>>>>>>>> Harken Lazy Jack system (installation manual at
>>>>>>>> http://www.harken.com/pdf/4058.pdf.) At West Marine, the small 
>>>>>>>> Harken Lazy Jack is about $200.
>>>>>>>>
>>>>>>>> Has anyone ever used the Harken Lazy Jack on an R22 main sail? 
>>>>>>>> Does it interfere with boom movement? Does it jam easily?
>>>>>>>>
>>>>>>>> I know, with IMF, you have no need for it. I still haven't been 
>>>>>>>> able to justify the cost of the new IMF mast & hardware on our 
>>>>>>>> R22.
>>>>>>>>
>>>>>>>> I was just thinking that the Lazy Jack looked interesting. 
>>>>>>>> Maybe run the control lines (downhaul &
>>>>>>>> halyard) back to the front of the cockpit, next to the pop-top, 
>>>>>>>> opposite to Genoa furling line. Comments?
>>>>>>>>
>>>>>>>>
>>>>>>>> Mike
>>>>>>>> s/v Shanghai'd Summer ('81)
>>>>>>>> __________________________________________________
>>>>>>>> Use Rhodes22-list at rhodes22.org, Help?
>>>>>>>> www.rhodes22.org/list
>>>>>>>>
>>>>>>>>
>>>>>>> __________________________________________________
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>>>>>>>
>>>>>> _________________________________________________________________
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>>>>>>
>>>>>>
>>>>> __________________________________________________
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>>>>>
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