Where can I find data for a Dufour 1800?

[seanfoster]

I've recently bought a Dufour 1800 and I'm having various head scratching problems (which this forum is helping with - an enormous thankyou to the people who have answered my questions!)

I'm designing a trailer for it, and I need to find out the centre of gravity (basically I want to know where to put the axles to make the noseweight of the trailer as low as possible)

This particular Dufour 1800 is slightly different to most of the others I've seen as it has a bulb keel and doesn't have an inboard engine.

Does anyone either know, or has any suggestions where I can look (I've trawled tinternet with no luck so far, and the dufour website points you to delears for contact info)

 

[MrCramp]

On modern trailer the axles are fixed to the frame by U bolts so that they can be moved backwards and forwards easily to adjust for different boats. Walk around any marina and have a look.

Here is a link to Indespension's site. Perhaps not easy to see the fising but read the text.

http://www.indespension.co.uk/b2c/app/I00810?ZTNOID=1230&slnk=1

Indespension used to produce a "Trailer Manual" which contained loads of information about building your own trailer, including plans. It also contains all the up to date legal information. For example are you aweare you cannot use hubs from a scrap yard. All braking systems have to be of the overrun (self-reverseing) type.

 

[Eygthene]

If your Dufour 1800 has the (moveable) plug-mounted outboard in the cockpit well and the water tank is empty and not too much heavy chain in the bows, I would start by taking the C of G as being close to the mid-length of the keel bulb, with the outboard in the cabin or off the boat.

When she is on the trailer, you will need to slide her forwards or aft a tad with a jack to get just the right amount of weight (to suit the spec of the towing vehicle) on the tow hitch (I used the old bathroom scales for that).

 

[rhumlady]

I owned a Doufor 1800 as my first boat. I believe there are three keel configurations, a swing, a fin and a shoal keel which I suspect had a bulb and is the one you have. We had an inboard 9hp Stuart Sole diesel and I remember the only time I dried her out she was bow heavy. Unfortunately I have no other info.
I do know she is quick though as Auberge is based on the Forth and regularly features in the results columns and wins the silverware.

 

[FullCircle]

[ QUOTE ]
If your Dufour 1800 has the (moveable) plug-mounted outboard in the cockpit well and the water tank is empty and not too much heavy chain in the bows, I would start by taking the C of G as being close to the mid-length of the keel bulb, with the outboard in the cabin or off the boat.

When she is on the trailer, you will need to slide her forwards or aft a tad with a jack to get just the right amount of weight (to suit the spec of the towing vehicle) on the tow hitch (I used the old bathroom scales for that).

[/ QUOTE ]

Good answer, second that.

 

[seanfoster]

Thanks for that, can you expand on shifting the boat with a jack?

 

[chamac]

I bought a Dufour 2800 in 2000 in South of France.
I picked up one of these.
http://www.rmtrailers.co.uk/fin.php
on the way from Ireland. The top one.
I priced the parts to make one myself and found it did not make sense to DIY.
The value of the trailer sold with the boat later.
Regarding positioning. Keep enough weight forward. If you don't the trailer will sway. You should be just about able to lift the tow hitch off the ground when its right....watch the back.
Your boats weights are different but with the 2800, the front of the bulb was slightly forward of the front axle if I remember right.
You might be able to (carefully) take the weight from under
the keel, through the trailer with a jack and gentle move the trailer back and forth. A crane or teleporter would be much safer.

 

[Eygthene]

Sorry not to have replied earlier Seanf, I rather lost sight of this thread until today. When I had built the trailer for my Eygthene 24 which is quite similar to your Dufour 1800, the keel rested in a steel channel which located it sideways, but left it free to slide fore/aft.

Then when the boat was in position, I rested the tow hitch on an old set of bathroom scales and used a couple of strong clamps to fix a block in between the sides of the channel, a foot or so in front of the bottom edge of the keel.

An old screw jack was fitted horizontally between the block and the front edge of the keel and by operating the jack I was able to slide the boat backwards a few inches until the weight on the tow hitch was right.

Then I welded a piece between the sides of the channel and just touching the front of the keel, to mark the proper place in future. This also stops any possibility of the boat sliding forwards when braking hard etc.

A stout warp round the back of the keel and brought forward is just there to avoid it slipping backwards going up any steep slopes.