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Lynch

J105 IRC

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Think I'll be going with a 105 for next boat

Any advice on what works best for IRC - headsail size spinnaker etc

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We raced against a J105 some ancient years ago with our J35. The 105 had a Genoa and was just quick as us upwind. Suffered downwind because of the short hoist of the kite.  So, I would say, go Genoa and masthead hoist for the kites. 

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I am doing a new jib 29 m2

we have problems in light winds but dont want to go with genoa.

 

next step is a new main 36 m2

oue kite is 96m2 probably the new one will be bigger

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Sack off the furler and give it a proper headsail with horizontal battens on hanks or foil. Nice non overlapping headsail with an inhauler system. Push spinnaker area up by 5% and get yourself a good spinnaker staysail and code 0. A super smooth racing hull finish is also a must. Strip out all excess weight you don’t need and lastly sail it the right way

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Well, most common response is bigger kites.  IRC treats kite nicely.  However I have a real problem with getting people to understand that when a boat is designed to carry Genoa’s as the 105 was originally designed. Why sacrifice up wind performance for the sake of a good rating.  
 

take two J35. One with Genoa, the other with a Jib.  W/L course.  The Genoa boat will owe the Jib boat roughly a minute and ten seconds per hour.  
 

they come off the line. By the time they get to the windward mark, the Genoa boat is easily two minutes ahead.  Downwind, no gains or losses. That race was over at the start.   And this come from experience.  
 

the only time I can see rating for a jib is for a long distance race with 75% of the race in reaching/running conditions. Or if you know it will blow 18kts from start to finish when you need to be on a jib instead of a Genoa.  But generally speaking, I favor a Genoa over a jib if the boat is designed that way. 

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In the UK in the Solent many of the irc racing fleet have moved away from overlappers, some of the J109s with a non overlapping J1 haven’t seen much of a performance loss unless it’s sub 6kts of wind. I’ve raced a couple of boats that made the switch including a J92 and the main observation is that in over 8kts or wind the boat doesn’t have the same low and fast speed mode that a boat with an overlapper has but it has a better height mode and net vmg was similar up to 12kts and then over that having a jib is better. All that whilst carrying a lower irc rating. To benefit from a non overlapper you kind of need to be on a headfoil or hanks. A boat with a headstay furler will be seriously compromised with a non overlapper.

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We have changed the wheel and now we are going with tiller.

also put inhauler like j99 and changed the hidraulic to cascade system.

could be interesting change rhe rudder to a newer design

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7 hours ago, JL92S said:

To benefit from a non overlapper you kind of need to be on a headfoil or hanks. A boat with a headstay furler will be seriously compromised with a non overlapper.

This is an important point that isn't made frequently enough. With a furler I found it extremely painful trying to get a nice shape with a narrow sheeting angle without choking it and stalling the boat. Especially if the furler is mounted above deck and you have a 9" gap between the bottom of the sail and the deck.

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On 10/7/2020 at 7:28 PM, Lynch said:

Think I'll be going with a 105 for next boat

Any advice on what works best for IRC - headsail size spinnaker etc

Inshore or offshore?  Crewed or shorthanded?

 

Did my time in the Solent 105 fleet (when that was a thing) and a bit on IRC.  Now race against 105s from time to time.  

I'd echo the advice to go big on the kite, but unless you're really wanting to clean up in sub 10 knots don't bother with a Genoa.  I haven't seen a successful IRC boat with a genoa for years, they just don't pay unless your venue is especially light.  If you're inshore racing then the crossover is probably less than 10 knots as to when the rating hit is worth it, and offshore it's only going to be times when you have long light wind beats, or legs too fine for a code zero that a genoa will pay.  Against that you carry a lot of rating around, and will probably spend more time with the Jib up anyway.


In general, compared to similar rated IRC boats around now, the 105 will be a little lacking upwind, and deep downwind in light/medium, but punches above its weight reaching in all wind strengths and downwind in big breeze.   It's perfectly possible to do well an a ww/lw track in a 105, but you have to be smart about it.  If you come off the line needing to point well to avoid falling into the dirt of a 109 or similar you're going to have bad time.  Being able to sail your own race will be key against a decent IRC fleet on a ww/lw track.  Offshore I'd take a 105 over anything even remotely in the same price bracket.      

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Inshore and offshore fully crewed but might do some double handed when crew not all available,

Any thoughts on code zero especially for offshore work

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1 hour ago, Lynch said:

Any thoughts on code zero especially for offshore work

de rigeur in IRC fleets but not sure whether the 105 sprit is suitable at full extension without modification

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13 hours ago, Snowden said:

de rigeur in IRC fleets but not sure whether the 105 sprit is suitable at full extension without modification

It'll need a bobstay.  

15 hours ago, Lynch said:

Inshore and offshore fully crewed but might do some double handed when crew not all available,

Any thoughts on code zero especially for offshore work

Give Key Yachting a bell, they'll know how to do it or be able to put you in touch with someone who's done it. 

Inshore a 105 won't hang with the Corbys or 109s upwind, but you should be considerably quicker downwind.  Especially when the breeze is up.  105 wouldn't be my pick if ww/lw IRC racing is your primary focus, but for a mix of inshore/offshore it's a very good boat for the price that they now ask.  

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J105 , Jester won the 2 handed division of the 2017 Fastnet beating the previous winner Night and Day ( JPK1010 ). It was setup hanked Jibs using horizontal battens. They had a J1 and a reefing J2+. Downwind was a Masthead A2 and A4 as well as a furling FRO. See picture of Jellybaby from Lymington using the same FRO.

 

IMG-2067.jpg

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Jester won 2H in 2015, we were next to them on the way down the DST.

It's been said before105 do very well offshore because of their reaching abilities, small headsails (#2) and big spinnakers always work in IRC and do well with the 105.

Diablo J was a riot double-handed (less so with the 3600) and many more did well, although less now with other allround design such as SF3200 (see Fluke going from 3200 to 105...)

Great design for cheap & fun sailing

 

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