Tuning an O'Day 25

Brian S · Aug 22, 2014

First, get Selden's "Hints and Advise" mast tuning booklet here: http://www.seldenmast.com/en/resources/rigging_instructions.html

You want about 3-6º of weather helm, so that the rudder provides some lift beating to windward. Your rake will be set to achieve this in your most common wind range, through trial and error. Since you don't have a one design class racing type boat, there will not be any tuning guides for an O'day 25, so trial and error is the name of the game...

Next, get this: http://shop.sailboatowners.com/prod.php?51998/Sail Trim Users Guide and possibly the companion laminated charts: http://shop.sailboatowners.com/prod.php?51997/Sail Trim Chart

Have a gander at the Don Guillette forum here: http://forums.oday.sailboatowners.com/forumdisplay.php?f=17

Finally, consider replacing your headsail. From what I have read on Don's forum, particularly with regards to Catalinas, it may be good to consider a 135% genoa unless you sail mostly in lighter winds. A 150% tends to overpower pretty quickly… But that is a debate for much later on...

RichBone · Aug 28, 2014

Racing can be very frustrating, especially against sailors that have their boats along time and know how to 'sail' them. It can take awhile to get to know your boat.
When you get your new sail have someone from the loft go out with you. He (or She) will trim it up and see how the the boat sails. They want you to be satisfied with your sail.
Like already mentioned tune the rigging so it has a little weather helm. The 25 was designed as a trailerable boat and the rigging isn't meant to be really taut. There were some posts on this a few years ago. Original instructions said something like "tighten turnbuckles one turn past hand tight" (what's hand tight on a 30 year old boat?). I don't readily recall. It's something that you need to play with. the forestay especially is important in that tension on it determines how full or shallow the draft is on the headsail.
Anyhow, the sailmaker can be very helpful in getting the sails to work right.

Jackdaw · Aug 28, 2014

Job #1 is getting a boat to sail to its rating.

If your sails are old/crap that will be very hard. Same goes with bottom condition. Excess stuff on board. Etc Etc.

The best place to find this out is on the initial starboard beat after the start. Look at similarly rated boats near you... how is your boat-speed and windward angle compared to them?

If you are with them then the game is about tactics, and sailing better/smarter.

If you are off the pace, make sure you are trimmed well. Then look at standing rigging adjustments, and sail condition.

The O25 is NOT a great raceboat. Don't expect great things. But it should be close to boats like Catalina 25s.

LANCE ON CLOUD NINE · Aug 28, 2014

it is very easy for too much stay tension to compress the deck under the mast or to pull out a chain plate from the wooden bulkhead (especially if the bulkhead has had the slightest bit of water wicked in down the side stay and through the deck). I would examine these areas first. Many O'Days that are raced have had these areas reinforced. Also the side stays are placed out so far that it is hard to get tight sheet angles - it would be interesting to play with a barber hauler on your new jib. Given the slow rating I always thought it would be fun to really get to know the boat, and to keep making slight improvements, to attempt to sneak up from the back of the pack. They sure don't expect us! Good luck, please keep posting your race results as you make changes.

Brian S · Oct 19, 2014

Isla-Mae, it is my impression that ablative paint is not recommended for racing, because it is not particularly smooth, and will slough off continuing to not be smooth. You would want a hard finish paint. Interlux VC-17m or Pettit ViVid are examples often applied to racing hulls.

Sunbird22358 · Aug 17, 2015

Rounding up In puffs is the boat's way of telling you that you have too much sail area up. It is also considered a safety feature since rounding up into the wind reduces the wind pressure on the sails and helps the boat recover and right herself instead of taking a knockdown.
Since you have the K/CB model 25, I'd try raising the CB a little in puffy conditions, experiment with just how much you need to raise the CB to "dial out" some of the weather helm. Raising the CB a little will move the center of lateral resistance (resistance to leeway) further aft, reducing the weather helm, however be careful not to raise it too much while beating as it may increase lee-helm (tendency of boat to turn off the wind instead of into the wind when a puff hits.) Changing the angle of the CB is one way to "fine-tune" the balance of the sail plan, thereby adjusting the amount of weather-helm vs Lee-helm, and should be much easier than adjusting the rake of the mast. You will most likely need to point up a little into the wind in order to take some of the sideways pressure off the CB in order to adjust it's position. I know that on my DS II I almost need to adjust the CB only when the boat is pointing nearly into the wind, or sailing nearly downwind.

Brian S · Aug 17, 2015

There is a post from Stu on the Catalina forums regarding the choice of a 150% vs. 135% genoa. I think the end result was that for most sailors, a 135% is the better sail choice, in that it can handle a higher range of wind. A 150% or 155% should probably only be flown by racers, and in lighter air.

If you aren't as keen on sail controls, then you might wish to start here: http://shop.odayowners.com/prod.php?51998/ This book by Don Guilette will really help you understand sail controls and effect on performance. It's not a racing performance book, but it's probably the be best book for non-technical racers I've seen that will get you at least 75% there.

In your earlier post, you say that up around 15 knots wind speed, the boat is definitely overpowered with the 150%. If you are routinely rounding up in winds less than that, then perhaps you could adjust your jib fairleads aft a bit to allow the top of the genoa to twist off, flatten the foot of the sail, and thus depower some. Also, you might relax your main leech tension to allow the top of the main to twist off. Does the O'day 25 have a traveller? If so, you'll use the mainsheet to control leech tension and twist, and angle of attack with the traveller, and having an easily adjusted traveller will allow you to let the traveller down for puffs. If you don't have a traveler, then you'll be trying to use the vang and easily adjusted topping lift to control leech tension, and allow the mainsheet to control angle of attack independently of leech tension. This is called vang sheeting. Unfortunately, vang sheeting is not as effective as a traveller, because with a traveller you can bring the boom higher than the centerline, and thus keep the main twisted properly (leech tension) while allowing higher pointing angles.

Sunbird22358 · Aug 18, 2015

The 25 does have a traveler, but the factory installed ,standard equipment traveler is a plain-Jane no frills track across the forward end of the cockpit, on the bridgedeck. Adjustment side to side is by track stops if I recall what my friend's 1979 25 had.

James19955 · Aug 24, 2015

I agree with Jackdaw and many of the other posts here, especially those about the size of a 150 jib.
I have an O'day 23 and it gets interesting in winds above 20 kts.
I do not race my boat but do strive to get the best out of her every time I hoist the sails.
I think a 150 is too big in winds above about 15 kts for a center-board type boat like ours where the major keel weight is close to the waterline. As you have noticed the boat will round up especially in winds greater than 15 kts with a 150. I have a 150 and it makes the boat point higher and go well in steady winds up to about 12 knots with puffs up to about 15. For winds greater than that the boat becomes a chore to handle rounding up etc etc.

About racing ... I have crewed in a number of boats for more than 20 years and my experience is that flying the telltales and keeping the main adjusted is the first step to doing well. The info by Don G on this web site is excellent as are the simpler sail adjustment sights which talk about the use of tell tales.
New sails help but getting what you have to "Sail well" is critical. There are lots of adjustments which can be made, - weight distribution of the crew, halyard tension, position of the cars, traveler position, boom position, Cunningham on the main, outhaul, leach lines on the jib, to name just a few. All of these make small differences but the first step is to drive a steady course and keep the power on. Rounding up is like putting a brake on. Having too much sail up and healing the boat is another issue Yeah it looks good and hearing the water rush along the rail is fun but it does nothing for boat speed or the ability to point towards the mark - bigger boats with significant keel depths and weights can carry a larger heel but the O'Days perform better - in my opinion - if you keep them on their feet by tucking a reef in for the upwind leg. When reefed the boat will sit better in the water, there will be less rounding up and they will sail faster, at least that is my experience.
The next time you are out enjoying a cruise in winds greater than say 15 and the boat rounds up, take a look at the stern and the position of the rudder and you will see the water flow showing you that the rudder is a brake and with a huge amount if water turbulence behind. This is just drag and now you have to get the boat going again. Try putting a tuck into the main and see how the boat sails.
If you have a speed indicator you can check speed improvements for the changes you make.
Either way its all just fun and everyday is a chance to improve your skills.
Fairs winds and keep us informed of your progress.
James

sdstef · Aug 24, 2015

Isla-Mae said:
Here is an update on the Isla Mae. A 2HP Honda replaced the Johnson 9.9. A full sized tri radial spinnaker by UK has been added. It took us a long time with lots of hairy moments to learn to deploy and retrieve this kits. Wow, it adds a lot of speed while flying. Raising and removing the spinnaker is still taking good time out of the advantage but we are encouraged. The remaining problem is overcoming "rounding Up" in the puffs. Is there a technique for overcoming this tendency when using the 150 genoa? Is there a mast rake that will work best for the 150 and also for a 135? I do not think it is normal to change the rake with the sail of choice. What is the most effective way to tweak this boat for speed? I just want to have the O'Day 25 sail to its rating. Thanks.

I have a 77 and I am pretty slow. I have an 8 h.p. Mercury 4 stroke hanging off the transom and some older sails . My 2 cents...
rounding up..shorten sail is all you can do. Be Johnny on the spot with the main sheet and dump the air. On the mast rake, without swept spreaders, I was told not to. Plus you will apply tons of undue stress to the cabin top and the chain plate/bulkheads.

ebsail · Aug 24, 2015

We do race our 25 in our club's Wed eve events. We set our mast with 0 rake. We use a new 2 full batten main and a 135% jib from a Catalina 25. We give away a lot of area here, since the jib is high cut. But visibility is great. Of course we don't win (except once) but we are always in the top 5 (out of 9 or so).
Things that helped us move up are:
Clean bottom, that's been faired and has no bumps. Clean the bottom every 30 days or more.
Tight headstay. As tight as you are willing to risk to reduce headstay sag.
Get a new traveler with roller bearing car. VERY IMPORTANT- Make sure the cam cleats are on the CAR. Not on the traveler ends. Otherwise you won't be able to open the starboard lazzeret Guess how I know?
Being able to lower the traveler to avoid rounding up is important. Also being able to haul the boom to centerline without a lot of leech tension in light air
As previously mentioned, move the centerboard aft by pulling it up and inch or two in strong wind.
Pick up the centerboard completely when going down wind.
And lots of practice. Reading all those books will help too.

Kestle · Aug 24, 2015

Rounding up is a bit overstated, IMHO. We routinely round up (slightly) in races as a way to bleed off gust energy. It is a degree of how much. It is also true that the rudder position tells you sail balance and rudder drag; that has to be reduced first. A balanced sailplan is the fastest.

Jeff

Stu Jackson · Aug 25, 2015

Brian S said:
There is a post from Stu on the Catalina forums regarding the choice of a 150% vs. 135% genoa. I think the end result was that for most sailors, a 135% is the better sail choice, in that it can handle a higher range of wind. A 150% or 155% should probably only be flown by racers, and in lighter air.

Well, he IS a racer and is still having issues with his 150. IIRC, he said he's getting a 140 even though many of us suggested a 130 or 135. Don's book, which has excellent sail trim information, also has about the very best How to Start a Sailboat Race discussion I have ever seen. Don's book should be required reading for anyone who owns a sailboat, unless they just want to tighten in their sails and leave them there regardless of what direction the wind is coming from.

Some do, ya know!

Here's the link:

A very illuminating and interesting discussion on co.com for those of you who might be in the market for a new jib.

http://forums.catalina.sailboatowners.com/showthread.php?t=155362

Please read all three pages. Enjoy.

Believe it or not, sometimes a smaller jib can do MUCH better than a bigger one. I have smoked a one-design boat with a larger headsail a few times. Heavy winds, to be sure, but it happens.

Jackdaw · Aug 25, 2015

Stu Jackson said:
Believe it or not, sometimes a smaller jib can do MUCH better than a bigger one. I have smoked a one-design boat with a larger headsail a few times. Heavy winds, to be sure, but it happens.

Once the breeze is up, a blade jib is the weapon of choice. Everyone with genoas will be trying to deal with excess pressure. Our F260 has a non-overlapping rig, so jib only. In very light air it sucks racing, but every boat on the lake fears us in 15+ knots. That's called a 'BlueJ day' on Lake Minnetonka.

Overall, best performance comes from matching your head-sail to expected conditions, with the proviso that you do so for the lulls/average, and deal with the puffs. Modern raceboats are almost all non-overlapping jib-only affairs, so this choice goes away. Only down-side is the a fore mentioned problem with racing in very light airs. But on older genoa boats like a oday 25, switching down to a blade in breeze will pay huge dividends.

Tuning an O'Day 25

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