Select to expand quoterobhow2 said..
Information & photos for L & H and Joe's queries.
1700mm to front track car centre; 440mm front car centre to rear most centre of track car.
2375mm front tip of board to 1st centreboard slot (centre of). 2nd rear most slot a further 75mm back.
Note 99.99% of the time sailing with the 7.3m2 sail & smaller I use the rear centreboard slot. The front position never seems to have the same balanced setup once on the rail sailing upwind. From memory all AUS racers used this location for the centreboard. The mast track is again 99.99% of the time at the very front for upwind sailing in all breezes. On my old IMCO One Design I found that the mast track can provide a better balanced setup, set back to 2 - 3 for upwind in the lighter range of winds. So similar sail sizes but different outcomes board to board.
The mast foot pin measures 25mm O/A in length (main body) & has a diameter of 13.85mm. Odd size, but it is what it is ! The white plastic washer sits on the track car.
robhow2, THANKS.. you have perfect sources (!) these pictures are taken from some olympic manual? or Lechner brochure? Its so hard to find any DII info on the web, so such input is really appreciated :)
Sorry to bother, but can you add more details about original NP 7.3m2 Olympic rig also? /boom x luff?/.
And concerning FINE tuning - suppose that Lechner s massive nose allows push track very forward in light wind/flat water/ to decrease tail drag. By the way :) ..how heavy you were those racing days? My 98kgs /90 in eighties/ used to be a handicap even for 340 l dinghy :).. I remember very light DII guys in light wind with nose and TAIL out of water - no drag, smooth and light... nightmare for me :)
The pin & catalogue photos come from the following Facebook site www.facebook.com/lechnerwindsurfing/ Scroll through it to find helpful information. I personally don't have any Lechner parts. For help tracking down Lechner parts I suggest you use the contact link on the following site www.opendivision2.org/
I used it about 3 years ago to find & access the centreboard flaps, which I had thought would be impossible to find. Eric B & Aymeric de P found them & within a few days they were on their way here via airmail. Absolutely fantastic ! 
Regarding the L & H query, D2 racing previous to 1988 had two weight divisions, with the heavies starting at 72 - 75 kgs. With only the 6.5m2 soft sail being used you could get away with being in the low to mid 60's as a lightweight for most wind conditions. I don't remember many heavy weights being in the high 80's or early 90's.
From 1989 / 1990 on the Lechner One Design didn't have weight divisions for the Olympics. With the more powerful 7.3m2 rig it favored a slightly heavier & fitter sailor (still no pumping, unlike the current Olympic class), so the general weight for the top sailors was around 65 - 70kgs. A few heavier sailors probably came to the fore in stronger winds.
If you were racing with us in the mid 80's & early 90's in NSW, AUS, I and a few others were your 'nightmare' !! I was definitely in the lighter weight range.
The one design rig consisted of a Neil Pryde cambered (nearly every batten !) sail, alloy boom & carbon C60 one piece 5m mast. It rigged up on a very short 120 - 130mm extension. The boom length required was approx 2400 - 2500mm. Both mast & boom were very light by even by to-days standards. The sail weighs 4.1kgs.
As far from sailing the board with your weight it's hard to say. The hull volume should be more than enough to make forward progress. Just experiment with rig fullness, mast location & foot placement. Perhaps just wait for stronger wind conditions to maximize the boards potential.
Select to expand quoterobhow2 said..
If you were racing with us in the mid 80's & early 90's in NSW, AUS, I and a few others were your 'nightmare' !! I was definitely in the lighter weight range.
Yep, you were a nightmare.....Grumble, grumble, grumble. 
The one design rig consisted of a Neil Pryde cambered (nearly every batten !) sail, alloy boom & carbon C60 one piece 5m mast. It rigged up on a very short 120 - 130mm extension. The boom length required was approx 2400 - 2500mm. Both mast & boom were very light by even by to-days standards. The sail weighs 4.1kgs.
As far from sailing the board with your weight it's hard to say. The hull volume should be more than enough to make forward progress. Just experiment with rig fullness, mast location & foot placement. Perhaps just wait for stronger wind conditions to maximize the boards potential.
Rob, do you know how the Lechner NP 7.3's mast compared to an IMCO mast in bend? I've got one of the NP 7.3s in storage but due to boom length issues I don't know if I've ever rigged it to see how it fits on an IMCO mast.
Chris, I have no definitive answer to your question, only a few insights from using both pieces of equipment over all those years.
The Lechner 7.3 luff round is definitely greater (in un-tensioned curve) than the IMCO 7.4. Both sails weigh nearly the same.
My IMCO 2 piece mast is 4955mm long & 2.6kgs. I think some referred to it as a carbon mast , but I doubt it, just look at the weight !
The 5010mm C60 NP Lechner mast (one piece) is only 2.15kgs, and it's definitely carbon.
In the distance past I did some bend tests, but not comparing IMCO to Lechner. The impression I have of both to-day is that the IMCO mast is slightly softer overall.
I would just rig it up & observe how the fullness appears progressing up from boom level, right to the top. The 7.3 Lechner rig has luff shape all along the mast even under high DH tension. Whereas rigging up the IMCO 7.4 on the 2 piece it flattened out quite appreciably in the head under high DH tension.
Hope that assists, cheers, Rob.
I once hung the required weight from the middle of the IMCO mast in the usual measuring method. I was wondering what in today's world would be similar. I don't have the numbers (or the mast) anymore unfortunately, however I remember clearly that the flex characteristic was way floppier in the top and way stiffer in the lower half than anything available at the moment. Of course the diameter is larger through the boom area too, so that tally's up in a sensible way. Can't speak for the NP7.3 mast, have always liked the look of that sail though.
Select to expand quote Another set of a390 measurements that I've copied from an email a while back to someone thinking of building one.... These from the tail so if anyone wants to get all OCD with it they could be checked against the 'from the nose' measurements above.
---------------------------------------------
Measurements to the stern are taken to a line at deck level perpendicular up from the keel line at the most aft tip of the transom.
1) Centerboard pivot to stern.
There are two c/b pivots at 1445 and 1515 from the stern. I use the forward one most of the time, shifting to the aft one when it's over 18 - 20 knots. You can achieve much the same effect as shifting to the aft pivot by simply raking the board a tad.
2) Back of mast track to max stern.
Back of the mast track fitting, including the foot pedal is at 1645 from the stern.
3) Mast track length.
The fitting in total measures 630 long.
4) Where the universal would be in furthest back position in relation to any of the other measurements.
Furthest back centre of mast step is at 1765 from stern, furthest forward is at 2215. There are 8 positions between these two, evenly spaced.
I very rarely use the forward most position, I think it might come into it's own with a longer boom and/or lighter rig. I mostly use the second forward position at 2150 as my most forward. The very aft position is really only for fully (fully!) powered up off the breeze, 20 knots +, the stern bogs otherwise.
My board is a '92 model, which has the mast track and c/b a little further aft than the earlier models. How much exactly I don't know. The footstrap inserts are placed slightly differently too.
Woah!!! Note: copying from gmail and pasting into Seabreeze does unexpected things!!! My previous post just needs reading through ignoring all the 'quote' boxes.
There's not enough time in life to fix computer glitches for me, I've got better things to do.
SAILBOARD - OPEN CLASS - 1982?
Hello DII community, maybe it 's OT, but maybe somebody can help. I can 't find any info about this SAILBOARD. Serial Nr. 4639240682 /so I suppose can be June 1982?/. Central sticker proudly says: 3x World Champion, Open Class 1981 USA. Probably it wasn 't DII, but hull is rounded enough :). I 'll appreciate any info: comments, memories, data, brochures. Thanks.
P.S: and thanks once more for previous answers and comments concerning Lechner dimensions, technique and tuning
Select to expand quotelongandheavy said..
SAILBOARD - OPEN CLASS - 1982?
Hello DII community, maybe it 's OT, but maybe somebody can help. I can 't find any info about this SAILBOARD. Serial Nr. 4639240682 /so I suppose can be June 1982?/. Central sticker proudly says: 3x World Champion, Open Class 1981 USA. Probably it wasn 't DII, but hull is rounded enough :). I 'll appreciate any info: comments, memories, data, brochures. Thanks.
P.S: and thanks once more for previous answers and comments concerning Lechner dimensions, technique and tuning
It's by Sailboards Germany and went under the name of Regatta. It was certainly a D2, early '80s style as Nelson Foils says.
We had a few out here, sailed by some of the best sailors in Australia. They were probably outmoded soon after by the Mistral M1 and then the Crit D2, before the class went Olympic and everyone switched to Davidsons and Lechners. It should still be fun to sail in the right conditions.
This is the Sailboard " Race" or called again Sailboard " Regatta", a very popular D2 from early 80s...Here is Brest FRA Championships
Same generation than Tornado DII, Oceanite Competition, Magnum + 390...
Very pleasant to sail apparently.
Select to expand quotelongandheavy said..
SAILBOARD - OPEN CLASS - 1982?
Hello DII community, maybe it 's OT, but maybe somebody can help. I can 't find any info about this SAILBOARD. Serial Nr. 4639240682 /so I suppose can be June 1982?/. Central sticker proudly says: 3x World Champion, Open Class 1981 USA. Probably it wasn 't DII, but hull is rounded enough :). I 'll appreciate any info: comments, memories, data, brochures. Thanks.
P.S: and thanks once more for previous answers and comments concerning Lechner dimensions, technique and tuning
There was one for sale here in the ACT recently , i wonder how well the plastic construction would last after 35 years or so.
this is mine in 1984 ;
Select to expand quoteKA360 said..
^^^ Hey Doug,Is that a photo of you or is that me?
this is yours with the pink sail ;
^^ Well there you go . I'd have guessed tightass brown would be his preferred choice.
Select to expand quotefjdoug said..longandheavy said..
SAILBOARD - OPEN CLASS - 1982?
Hello DII community, maybe it 's OT, but maybe somebody can help. I can 't find any info about this SAILBOARD. Serial Nr. 4639240682 /so I suppose can be June 1982?/. Central sticker proudly says: 3x World Champion, Open Class 1981 USA. Probably it wasn 't DII, but hull is rounded enough :). I 'll appreciate any info: comments, memories, data, brochures. Thanks.
P.S: and thanks once more for previous answers and comments concerning Lechner dimensions, technique and tuning
There was one for sale here in the ACT recently , i wonder how well the plastic construction would last after 35 years or so.
this is mine in 1984 ;
They last very well. ...Pending how owners take care of them of course.
We regularly find some in good shape in the US
Second sail on the DB2 went well except for the gybing part, I can sail it downwind ok but can't gybe the thing.
Sailed the raceboard yesterday in gusty westerly conditions up to or maybe even over 20kts and didn't fall off all day, sailed the DB2 today in 8-10knts and went swimming multiple times, they certainly are a challenge to gybe I will have to take another look at that french team from the 80s to get some technique tips
I've had a round hull board and love my new old raceboard.
Its kind of like comparing really spastic to just spastic.
Nothing compares to planning a short board.
But any long board is way better than sitting on the beach .
New Wally's , old Wally's , better than sitting on the beach.
A $ 50 dunger is better than sitting on the beach.
Fifty bucks and a trip to the beach , gold. At least it's worth the fish and chips !
..... Mabee dad wants another go......?
Select to expand quotecammd said..
Second sail on the DB2 went well except for the gybing part, I can sail it downwind ok but can't gybe the thing.
Sailed the raceboard yesterday in gusty westerly conditions up to or maybe even over 20kts and didn't fall off all day, sailed the DB2 today in 8-10knts and went swimming multiple times, they certainly are a challenge to gybe I will have to take another look at that french team from the 80s to get some technique tips
Woohoo! Nice one. Latest repair feeling solid?
Yes the repair felt solid, I spent a couple of hours on it, still have a leak somewhere, had maybe a cup of water in it when pulled it out but nothing like it was. Will have to do the soapy water test to find it.
I modified the Lechner centreboard so it works perfectly now, its very sensitive to centreboad adjustment, it can actually go a little to far forward when fully down and if it is either a little far forward or a little far back it doesn't roll easily onto the rail but once in the sweet spot it rolled onto the leeward rail, increased speed and pointed a little higher. Have to be careful when it powers up that it doesn't roll to far, I ended up flipping it once (no footstraps to muscle it back down like a raceboard), that will just take a little getting used to how far to let it roll or adjust the board to suit wind strength I guess.
I love the technical aspects of longboards, when you get everything tuned and working together they are a pleasure to sail, its that "balanced efficiency" you described at the beginning of this thread.
The gasket's work very well, just Dacron sewn over pattern mylar and glued in place.
I took the opportunity while I was repairing the deck to remount the mast track, its an old RSX track that was made up of spare parts so its was a bit dodgy to start with but seemed to work ok out of the board but jammed once screwed in place. I think it was getting twisted or bent a bit as it was screwed in place (I had to modify the board for it to fit), anyway a couple of washers placed under the track seems to have fixed that and the track is now working correctly as well.
I might try it with my Aerolte sail next to see how it goes with a different sail
Select to expand quoteCan10 said..
And to finish so you know everything about ........ SAILBOARD REGATTA / RACE
Thanks for good news.. 2nd D2 board in my "collection".
Looking forward to test it. Joint/base is piece of art... I am not sure if boom is an original one, any memories?
Select to expand quotecammd said..
Yes the repair felt solid, I spent a couple of hours on it, still have a leak somewhere, had maybe a cup of water in it when pulled it out but nothing like it was. Will have to do the soapy water test to find it.
I modified the Lechner centreboard so it works perfectly now, its very sensitive to centreboad adjustment, it can actually go a little to far forward when fully down and if it is either a little far forward or a little far back it doesn't roll easily onto the rail but once in the sweet spot it rolled onto the leeward rail, increased speed and pointed a little higher. Have to be careful when it powers up that it doesn't roll to far, I ended up flipping it once (no footstraps to muscle it back down like a raceboard), that will just take a little getting used to how far to let it roll or adjust the board to suit wind strength I guess.
I love the technical aspects of longboards, when you get everything tuned and working together they are a pleasure to sail, its that "balanced efficiency" you described at the beginning of this thread.
The gasket's work very well, just Dacron sewn over pattern mylar and glued in place.
I took the opportunity while I was repairing the deck to remount the mast track, its an old RSX track that was made up of spare parts so its was a bit dodgy to start with but seemed to work ok out of the board but jammed once screwed in place. I think it was getting twisted or bent a bit as it was screwed in place (I had to modify the board for it to fit), anyway a couple of washers placed under the track seems to have fixed that and the track is now working correctly as well.
I might try it with my Aerolte sail next to see how it goes with a different sail
Cool! You're going to have a lot of fun with it I'm sure. Congratulations on pushing through with the rebuild.
The new Davidson !
www.facebook.com/alain.cadre.9/videos/1143402815811395/
www.facebook.com/alain.cadre.9/videos/1143402939144716/
A bit of lightwind cruising footage on my Dobelman D2 a couple of weeks ago while my kids were training with the Techno squad
