Mast Rake

[Siamese]

The mast on my 309 has a pronounced rake. Sorry, about the lack of pictures, but we'll see if it gets to that. Suffice to say that it doesn't have the most rake in my particular marina, but it's very noticeable.

I'm curious if there's a set amount of rake for the 309, and how is that measured?

Also, is the forestay on the 309 a fixed length, or is there a turnbuckle under the roller furling gear for adjustment?

I'm aware of the trade-offs in performance with regard to mast rake, so what I'm asking here is what is the spec for the 309?

 

[jsalley]

Not sure if there's a spec, but most 309's seem to have a lot of weather helm after their initial commissioning. I was able to decrease it to a reasonable level by increasing rake about 2-3 degrees. Yes, there's a turnbuckle under the furler, but you have to partially disassemble the furler drum to access it - read up on it in the Schaefer manual.

 

[GKuffner]

Selden says that there should be 1degree of rake on the mast. The 309 has a mast that is 44'6" so 1 degree is about 9". I also put 4-5" of bow in the mast when I rig it (you can't put too much in as it could affect the furler). If you use less rake than you currently have you may have to shorten the length of the jib stay (to maintain the proper tension when adjusting the backstay) which requires removing the jib and partially disassembling the furler to access the turnbuckle.

Gary
Glory Days
C309 no. 136

 

[Pompadi]

After reading this thread I checked out our 309

We have almost no rake or bend in the mast, weather helm occurs after about 16 knots unless I've some extra bodies on the side
Our previous boat had an adjustable back stay which helped to de power the main and help point higher, but I now rely on the vang and out haul to flatten the sail then ease the traveller to reduce the weather helm

We haven't had the rig checked since the boat was purchased in 2006, so it might be over due now

What benefits have you guys found with the adjustments you've made ?
Any photos would be helpful

Cheers
Steve

 

[jsalley]

My boat as originally set up had maybe 1-2 degrees of rake, and would start trying to round up in 10 knots of wind under full sail, and become uncontrollable in more than 15 unless substantially reefed. I increased the rake to about 4 degrees, and it's like a different boat. Balances well under full sail (rudder nearly centered) up to about 15 knots, and I usually don't reef until about 18-20 sustained. I also keep the rig tensioned according to the previous threads and check it a couple of times a season with a Loos gauge.

 

[GKuffner]

We don't race our C309 but my wife and I do pay attention to our sails in order to maximize performance. Like I said in my previous post, I have about 9" of rake and 4" of bow in the mast. The rake was set by the dealer when he commissioned the boat. Also, since I have a 150 genny, i have a lot of tension on the backstay as I want to minimize any leeward sag in the forestay. I tension all the cap and intermediate shrouds to 15% of their breaking strength as measured with a Loos gauge.

I've also had the leach of the mainsail cut down by a foot. This was done to allow me to tension the boom and not hit the bimini. The benefit is that I can now get the main very flat with the outhaul and the boomvang. I then rely on the traveler to de-power the main in gusts. Once the boat persistently heals over 20 degrees I reef the main.

Like you I start to get weather helm at around 16K, so there doesn't seem to be much difference between our setups.

Gary
C309 No 136

 

[Pompadi]

I'll have a closer look to see what we have and get the rigger to check things over

Gary , It's interesting that you reef the main first , is there a particular reason to do that ?

We always reduce the head sail first which means less winching and quicker tacking, if we still have to ease the traveller too often then we start reducing the main.

We fitted a clutch to the head sail furling line so it's easy to pull in a couple of feet as we tack. We soon got fed up with burnt fingers trying to tie off the line with 20 knots hitting the sail

We also find the boat points higher with the smaller head sail, it doesn't hit the top spreader when winched on and has a flatter shape

 

[GKuffner]

Steve,

I reef the main first as a personal preference. I've tried doing both though. I also put a clutch on the jib furling line and recommend it to everyone. I find furling the main while underway and on a starboard tac to be quite easy. If the boat is still heeled at over 20 degrees then I reef the jib. I've also installed adjustable jib cars which I really like.

Gary

 

[Pompadi]

Gary
I've been thinking about getting adjustable cars
What brand are your jib cars, can you make all adjustments while under load ?
Do you have any photos of them on your boat
Steve

Hmmm seem to have got off the topic ...
Might need to start a thread listing all the 309 modifications people have done

 

[GKuffner]

Genoa Cars

Steve,

I finally took some pics of the Garhauer E-Z Adjust genoa cars that I installed. They work really well even in stiff winds and were were easy to install.

Gary

 

[Pompadi]

Thanks Gary
I'll add those to the list
It's a long one ..!
Steve