Go Back   Starboard Forums > Windsurfing School

Reply
 
Thread Tools Display Modes
Old 28th July 2009, 01:22 AM   #1
johntr
Member
 
Join Date: Jun 2007
Posts: 26
Default Gemini Experience

Roger:

So: our Gemini arrived last week, and we finally got to try it on Friday. It went great! I sailed with my wife and daughter (at different times), and we had no problem sailing out and back. Way easier than we had hoped. (It was essential that they're both experienced sailors. With beginners I imagine it would be very frustrating trying to keep th two sails up.) I was the only one who fell off the whole time, and I only fell twice in an hour or so of sailing. (Turns out we can't figure out tacking on the board. Gybing went great, though.) We found planing really easy on the board -- though it didn't seem to "take off" like my Start or Go board does. (But we were a bit underpowered, with only about 10 knots, sailing with a 7.4 on back, and a 5.0 Ripper on front. We had to turn downwind a bit to get planing.)

The one *huge* problem we have is that we need a weed fin. We were dragging a pile of weeds literally a meter in diameter by the time we finished! The problem is that our 56cm Curtis Someweed has a big extension on the front that would interfere with the slot for the centerboard (so we used the 70cm pointer that came with the Gemini). Do you have a weed fin that does not have this problem?

Also: how do you decide about fins for the Gemini? If you're planning to schlog do you just use a small fin and the centerboard (which kicks up to drop weeds)?

Also: our weed fin has a different screw thread than the big fin screws that came with the Gemini. I'd like to change my fins to all use the same screws. Is there one of these screw sizes that is more standard with Starboard boards these days? Is it easy to change the fin screw size?

Thanks,
John
johntr is offline   Reply With Quote
Old 28th July 2009, 06:30 AM   #2
Roger
Dream Team - School Guru
 
Join Date: Aug 2006
Posts: 2,112
Default

Hi John,
Glad to hear your first "voyages" on the Gemini were both fun and successful.
I use a 40 cm Design Lessacher Formula Weed on the Gemini to avoid the interference between the fin overhang and the rear end of the CB.
The Lessacher fin has no overhang.
If you are in Hatteras this weekend, I'll be down and you are welcome to try out my
40 cm Lessacher Formula Duo.

http://www.designlessacher.com/Websi...mula_Weed.html

I wish I had a Gemini to measure, but I'm not in Hatteras and the only Gemini I know of is the rental board at Sailworld Hatteras.
What is the dimension (inches or cms) from the front of the fin box to the rear of the CB slot.
I'm thinking that maybe a Tangent Reaper 42 might have less overhang and would work OK.

I always used the Lessacher 40 cm Formula Duo as it's all the fin the Gemini needs, even with 9.0 m2+ rigs on the rear.

As far as the theads, the Curtis Someweed probably has 1/4"-20 tpi UNC threads in it.
Most were made with 6 mm-1.0 metric barrel nuts, but some did have the 1/4-20s.
It's not a real good idea, but you can tap the 6 mm x1.0 metric inserts out to use 1/4-20 fin screws. There's just enough diameter left in the barrel nut to get some about 1/2 strength 1/4-20 threads if you get a 1/4-20 tap.
Better to check with Gorge Fin Co. (used to be Curtis Fins) to get some metric barrel nuts for your big Someweed. Get the new barrel nuts and use an appropriately sized round punch to drive out the old barrel nuts and insert the new metric barrel nuts.
All Starboard fins come with 6mm-1.0 pitch barrel nuts and all Starboards (except "A" box boards) come with 6mm-1.0 pitch fin screws.
Check this link on the fin screws:

http://www.star-board.com/2009/pages...st_finBolt.php

Hope this helps,
Roger is offline   Reply With Quote
Old 28th July 2009, 11:15 PM   #3
johntr
Member
 
Join Date: Jun 2007
Posts: 26
Default

Thanks, Roger. Great stuff as always. I'll write Curtis about the fin bolts, as 1/2 strength doesn't sound wise the way I drive those fins .

Where do you buy your fins? I can't find Lessacher fins for sale. I wrote Wolfgang in my pidgeon German, so we'll see what he suggests. (In a slightly related note, I found a forum post in which Wolfgang suggests moving the mast foot back 8-10 cm when using a weed fin. Is that your experience? On Sunday with my Curtis Someweed on my 2001 Start, I had my 11 meter Retro *all the way forward*, and it felt pretty balanced. The reason I had it so far forward is the previous outing with the 11 meter Retro -- my first with the new sail -- I was struggling to stay off the wind. With the mast foot forward I was planing any time the wind got above a gentle breeze (I'd guess 7-8 knots), and the rig was easy to sail.)

I'll measure the amount of room I have for the overhang tonight. I don't think it's very much .

Thanks,
John
johntr is offline   Reply With Quote
Old 29th July 2009, 10:48 AM   #4
Roger
Dream Team - School Guru
 
Join Date: Aug 2006
Posts: 2,112
Default

Hi John,
I got my Lessacher fins straight from Wolfgang.
You can also order them from TekknoSport, DE in Germany.
Either way, the international credit card transaction is pretty easy.
You will have to buy Wolfgang's fins in Europe, there is no USA distribution
that I know of.
I always run my mast foot fairly far back in the slot, and I use weed fins (all kinds and
sizes of weed fins) but I've never really found it necessary to change the trim of the board.
If your board is well balanced with the mast foot well forward with your 11.0, then sail it that way.
For me, at my weight, that would really slow the board down, but I haven't sailed an 11.0 m2 in a number of years.
If you are having trouble heading off the wind, why not simply stand the rig up slightly to turn you off the wind.
Also, if you are using the big Curtis Someweed, you won't get the same upwind performance that you would with a vertical race fin.
If you were planing as easily as you suggest, you must be doing all the right things, right?
I'll await your measurment of the overhang distance.
Hope this helps,
Roger is offline   Reply With Quote
Old 31st July 2009, 07:12 AM   #5
johntr
Member
 
Join Date: Jun 2007
Posts: 26
Default

The Gemini fin slot is 1 1/8" from the start of the cutout for the centerboard, or 1 3/4" from the place where the centerboard comes out of its slot. (The slot is a little bigger than it has to be.)

Any weed fins that have that small of an overhang?

Thanks,
John
johntr is offline   Reply With Quote
Old 31st July 2009, 07:48 AM   #6
Roger
Dream Team - School Guru
 
Join Date: Aug 2006
Posts: 2,112
Default

Hi John,
I'll check the Tangent Reapers this weekend down in Hatteras.
Send me a private message if you will and I'll give you my phone number.
I've got some ideas on a roof rack for the Gemini on your Wells Cargo.
Hope this helps.
Roger is offline   Reply With Quote
Old 12th August 2009, 01:00 AM   #7
johntr
Member
 
Join Date: Jun 2007
Posts: 26
Default

Thanks, Roger. I'll contact you privately too.

Was on vacation last week at a my family's lake place. Got in four days of sailing, which is a miracle for a midwest lake in the summer. I didn't get out on a single once, because everyone was so excited to try out the tandem.

We had a great experience. Most of the sailing was with my on the back with a 9.0 Retro sail, and my wife or daughter on front with a 5.0 Retro Ripper sail. We were in 10-14 knots most of the time, and were having great rides across the lake. The board jumps to third gear really easily. It took a little more wind to get into fourth: in third gear the front of the board would lift the front sailor six inches or so into the air (!), and we'd be going probably 15 mph. Just a little more wind and the board would flatten out and take off. I wasn't wearing a GPS, but based on "feel" from when I've worn a GPS on my start I'd guess we were going 22-24 mph in fourth gear. The ride was silky smooth, even over moderate waves, and my wife and daughter really enjoyed the experience of flying over the water without having to carry a monster sail. (My daughter said "this makes windsurfing a team sport"!)

I also sailed with my brother in similar wind. He carried a 7.4 meter O2 from the Loft, and I carried the 9.0 Retro. Even with two 200 pound men on the board, she still lit up and took off. We had an absolute blast tearing across the lake. I even sailed with my dad (he's 70, and carried the 5.0 Retro), and in the gusts the two of us were able to take off, too. A very fun way to share the speed and excitement of planing with other windsurfers!

However, I would be very careful about sailing that fast with less experienced sailors. (My dad, brother, wife, and daughter are all good solid sailors on their own, who don't generally plane, but seldom fall in the water or even drop a sail.) In schlogging mode the board is fine with a beginner (I tried with my brother-in-law, who was a good sport), but it is very scary to go fast when you don't trust the person in front to be able to handle his or her sail as the apparent wind comes up, or if you come across chop. At speed, that extra mast and boom could become dangerous!

Two minor questions about the board: (1) I don't have a clear idea when to use the drop-down centerboard. We used it all the time in schlogging mode, and often in third gear (because I didn't know the gust was coming). Very occasionally in fourth gear the big extra centerboard became a bit much to handle, but for the most part two sailors could muscle it down. (2) We didn't install the straps, so I didn't have a chance to try them, but they seem further back then I usually wanted my feet. Any experience with the straps? (I should say that it was surprising to me we could get the Gemini into fourth gear without the straps, and without it feeling scary most of the time. I think it's because the board is just so huge that it planed early and easy, and was very controllable even at high speed. On my single I would have been terrified at that speed out of the straps.)

Thanks!
John
johntr is offline   Reply With Quote
Old 13th August 2009, 11:45 AM   #8
Roger
Dream Team - School Guru
 
Join Date: Aug 2006
Posts: 2,112
Default

Hi John,
"Two minor questions about the board:"
"(1) I don't have a clear idea when to use the drop-down centerboard. We used it all the time in schlogging mode, and often in third gear (because I didn't know the gust was coming). Very occasionally in fourth gear the big extra centerboard became a bit much to handle, but for the most part two sailors could muscle it down."

I never really used the centerboard unless it was really sub planing conditions.
In clear water (no weeds) the stock fin does a good job and adding the CB just seemed to cause alot of extra drag and slow things down.
You can tip the Gemini upwind rail down a little (both sailors step a little off center toward the upwind side) and it goes upwind in nearly planing speeds, and once you are planing, if you put the footstraps on, you can crank upwind off the fin really well.
Balancing the front and rear sails (smaller in front for sure) can help you stay upwind as well.

"(2) We didn't install the straps, so I didn't have a chance to try them, but they seem further back then I usually wanted my feet. Any experience with the straps? (I should say that it was surprising to me we could get the Gemini into fourth gear without the straps, and without it feeling scary most of the time. I think it's because the board is just so huge that it planed early and easy, and was very controllable even at high speed. On my single I would have been terrified at that speed out of the straps.)"

I used all the straps on the Gemini I had since day one
They seem really far back, but that's where your weight needs to be.
Get your board strapped up, and you will find it's real comfortable back there.
And, for your crew up forward, having their feet in the straps always seemed to
get them to settle down so you could really get the board cranking.
Bill (from NC/NH (I think??) and I took the Gemini out with 2 4.8 m2 Sailworks Huckers one day.
I have to tell you that in high winds the Gemini really get rolling, even with 2 very small rigs.
Only issue that day was we needed a big steam whistle to get the guys on 80-100 liter shortboards out of our way, cause when the Gemini gets rolling that fast, it steers about like an aircraft carrier or super tanker.
Hope this helps,
R
Roger is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +7. The time now is 10:39 PM.