Announcements
New Discussions
Previous Thread
Next Thread
Print Thread
Rate Thread
Hop To
Page 1 of 2 1 2
vmg for uni #231946
05/05/11 05:35 AM
05/05/11 05:35 AM
Joined: Jan 2009
Posts: 5,525
pgp Offline OP
Carpal Tunnel
pgp  Offline OP
Carpal Tunnel

Joined: Jan 2009
Posts: 5,525
Most of the uni guys I've talked to are ready to throw in the towel. The feeling is the sloops walk away upwind.

So what is the best vmg for uni? Seems to me that if the sloop is faster the only thing left is to point higher.

Seriously, what are the technical reasons a Uni doesn't go to weather as well as an A cat?

Last edited by pgp; 05/05/11 06:22 AM.

Pete Pollard
Blade 702

'When you have a lot of things to do, it's best to get your nap out of the way first.

--Advertisement--
Re: vmg for uni [Re: pgp] #231953
05/05/11 07:12 AM
05/05/11 07:12 AM
Joined: Nov 2005
Posts: 69
Live in Germany, House in UK, ...
DanTnz Offline
journeyman
DanTnz  Offline
journeyman

Joined: Nov 2005
Posts: 69
Live in Germany, House in UK, ...
I'm no expert and I've never raced an A, but I reckon these would be big factors:

Less windage (no spin gear causing drag).
Much lighter weight
2 ft extra length = greater displacement mode hullspeed.
Higher aspect rig.
The guys sailing them have been doing it a lot longer!


Re: vmg for uni [Re: DanTnz] #231960
05/05/11 08:15 AM
05/05/11 08:15 AM
Joined: Jul 2007
Posts: 439
Memphis, TN
M
mikeborden Offline
addict
mikeborden  Offline
addict
M

Joined: Jul 2007
Posts: 439
Memphis, TN
The only time that I think the Sloop guys walk away from us is when it's blowing over 15 knots. More leverage which equals more weight. Where as the Uni guys are lighter with less leverage.

Here is the way I see it and some of the other guys I talk to see it.

0-5 kts everyone is pretty much equal.
5-10 kts- Uni guys have the advantage if they know how to sail the boat. They trap out earlier and can go downwind better because they can get the hull flying.
10-15 kts everyone is equal again except a few exceptions of where the Uni guy might not be heavy enough to leverage the boat or they can't depower enough.
15+kts-Sloop has the advantage because of weight/leverage. This is where the Sloops can and will walk away from us. They have more weight to leverage the boat.

A-cats are lighter, but light weight doesn't mean they can go faster or the F16 Uni's would be flying upwind in 15 kts of wind with no problems. The A's rigs are optimized for their weight and they do have more hull length to help.

Mike





Viper USA 132

1984 Hobie 18
Re: vmg for uni [Re: mikeborden] #231961
05/05/11 08:25 AM
05/05/11 08:25 AM
Joined: Jan 2005
Posts: 6,049
Sebring, Florida.
Timbo Offline
Carpal Tunnel
Timbo  Offline
Carpal Tunnel

Joined: Jan 2005
Posts: 6,049
Sebring, Florida.
As DanTnz said above, the A's have a better sail area to weight ratio upwind. But I have done better vs. sloops in more wind, not less. I think in very light air a light sloop crew does better because of the jib. In heavier air, once the light sloop crew has to depower, then the Uni guys can stay with them, upwind, usually.

BUT...what then happens is the sloop crews kick butt at the spinnaker set and more so on the douse, as the skipper can keep driving fast while the crew does all the spinny work.

I am not ready to throw in the towel on racing Uni, I enjoy the challenge of doing it, all by myself.


Blade F16
#777
Re: vmg for uni [Re: Timbo] #231964
05/05/11 08:46 AM
05/05/11 08:46 AM
Joined: Jul 2007
Posts: 439
Memphis, TN
M
mikeborden Offline
addict
mikeborden  Offline
addict
M

Joined: Jul 2007
Posts: 439
Memphis, TN
Timbo,
Since you do or have done better in higher winds against sloops, what is your weight then? I have met you before and I have an idea how much you weigh, but I'm not going to guess. smile



I'm trying to dispel the notion that lighter is always better.

I weigh 175 and Chris Amador weighs about 15lbs less. We both have problems keeping up with Sloops after the wind starts blowing over 15kts. We'll depower as much as possible and we are still overpowered, so we end up pointing too high and loose ground over the Sloops.


Mike


Viper USA 132

1984 Hobie 18
Re: vmg for uni [Re: pgp] #231967
05/05/11 09:53 AM
05/05/11 09:53 AM
Joined: Jun 2001
Posts: 548
MERRITTISLAND, FL
Matt M Offline
addict
Matt M  Offline
addict

Joined: Jun 2001
Posts: 548
MERRITTISLAND, FL
Originally Posted by pgp
Most of the uni guys I've talked to are ready to throw in the towel. The feeling is the sloops walk away upwind.

So what is the best vmg for uni? Seems to me that if the sloop is faster the only thing left is to point higher.

Seriously, what are the technical reasons a Uni doesn't go to weather as well as an A cat?


Like Dan said,

Lighter weight, increased water line and higher aspect sail, makes the A a better performer than a Uni F16 in theory. I have raced Robbie a couple of times now at GYC F16 uni vs his A and it has not been very much difference. I attribute most of the difference to his normally being able to kick my butt sailing upwind anyway.

The F16 uni vs sloop (upwind) is a bit different. In bigger wind there is an overpower issue as the F16 has a lot of sail. Until you are overpowered (Pete do not take this personal) the other issue is more related to driver skill. Uni is a lot harder to sail than a sloop. With limited sail area, there is a theoretical advantage to uni. Sloop though, has a jib and that in reality really can help keep you from pinching as bad and provides a lot better and quicker feedback on the wind.

Your comment above about pointing higher is likely part of the problem. Pointing higher is not about your angle of attack. Trying to point will lose you a lot of speed and height on the course. Hull speed is the key. Little things like not immediately rounding up in puffs and doing everything you can to go faster will ultimately place you higher on the course.

Re: vmg for uni [Re: mikeborden] #231969
05/05/11 10:03 AM
05/05/11 10:03 AM
Joined: Jan 2005
Posts: 6,049
Sebring, Florida.
Timbo Offline
Carpal Tunnel
Timbo  Offline
Carpal Tunnel

Joined: Jan 2005
Posts: 6,049
Sebring, Florida.
Originally Posted by mikeborden
Timbo,
Since you do or have done better in higher winds against sloops, what is your weight then? I have met you before and I have an idea how much you weigh, but I'm not going to guess. smile



I'm trying to dispel the notion that lighter is always better.

I weigh 175 and Chris Amador weighs about 15lbs less. We both have problems keeping up with Sloops after the wind starts blowing over 15kts. We'll depower as much as possible and we are still overpowered, so we end up pointing too high and loose ground over the Sloops.


Mike



Mike, I've been anywhere from 205 two years ago to 185 today (trying to get to 165 so I can get an A cat!). I did notice the difference in lost righting moment, that's why I always pig out on beer and pizza the night before, if I know it's going to be blowing the next day!

But any more than about 15 knots, I'm pretty much screwed when sailing Uni going upwind. It does make for a fun ride on the way downhill though!


Blade F16
#777
Re: vmg for uni [Re: Timbo] #231970
05/05/11 10:09 AM
05/05/11 10:09 AM
Joined: Jul 2007
Posts: 439
Memphis, TN
M
mikeborden Offline
addict
mikeborden  Offline
addict
M

Joined: Jul 2007
Posts: 439
Memphis, TN
Dang! You've lost a lot of weight! That's good!

Mike


Viper USA 132

1984 Hobie 18
Re: vmg for uni [Re: Matt M] #231973
05/05/11 10:25 AM
05/05/11 10:25 AM
Joined: Jan 2009
Posts: 5,525
pgp Offline OP
Carpal Tunnel
pgp  Offline OP
Carpal Tunnel

Joined: Jan 2009
Posts: 5,525
Not taking it personally Matt, just trying to define the issue.

My best result vs sloop is in light air, Tim and Mike in heavier air, CAB (I think) concentrates on the spin run.

Like Tim, I'm unwilling to quit. It is fun and challenging but frustrating at times.

So, what kind of settings are you uni guys using to weather? Particularly mast rotation. That is critical, yes?


Pete Pollard
Blade 702

'When you have a lot of things to do, it's best to get your nap out of the way first.

Re: vmg for uni [Re: pgp] #231974
05/05/11 10:32 AM
05/05/11 10:32 AM
Joined: Nov 2002
Posts: 465
FL
sail7seas Offline
addict
sail7seas  Offline
addict

Joined: Nov 2002
Posts: 465
FL
How much of a difference does a purpose built Uni main make?

Re: vmg for uni [Re: sail7seas] #231978
05/05/11 10:42 AM
05/05/11 10:42 AM
Joined: Jan 2009
Posts: 5,525
pgp Offline OP
Carpal Tunnel
pgp  Offline OP
Carpal Tunnel

Joined: Jan 2009
Posts: 5,525
You'd have to ask Karl, he's the only one I know that uses one.


Pete Pollard
Blade 702

'When you have a lot of things to do, it's best to get your nap out of the way first.

Re: vmg for uni [Re: pgp] #231981
05/05/11 11:16 AM
05/05/11 11:16 AM
Joined: Feb 2005
Posts: 4,118
Northfield Mn
Karl_Brogger Offline
Carpal Tunnel
Karl_Brogger  Offline
Carpal Tunnel

Joined: Feb 2005
Posts: 4,118
Northfield Mn
With a flatter main you're not maxing out cunningham as quickly. When you are maxed out you can keep it sheeted harder for longer before you have to start sheeting out and footing off to keep the boat rolling. Not talking about gusts here. I haven't felt short on power in lighter air either, but I do adjust diamond tension on the water if conditions change drastically.

Matt says you can get them result through spreader rake, and through diamond tension, and yes you can flatten the sail dramatically, (and if you go real crazy you can make the top really fall off), but I was really hunting for power when the wind lightened up with those settings. I think I took it to 42 on a black Loos gauge, and something like 2-1/4" of speaker rake. It was an obscene amount of prebend. Hindsight I don't think any of those numbers is safe for that mast, but it did survive.


I'm boatless.
Re: vmg for uni [Re: Karl_Brogger] #231985
05/05/11 12:41 PM
05/05/11 12:41 PM
Joined: Jun 2001
Posts: 548
MERRITTISLAND, FL
Matt M Offline
addict
Matt M  Offline
addict

Joined: Jun 2001
Posts: 548
MERRITTISLAND, FL
Originally Posted by Karl_Brogger
With a flatter main you're not maxing out cunningham as quickly. When you are maxed out you can keep it sheeted harder for longer before you have to start sheeting out and footing off to keep the boat rolling. Not talking about gusts here. I haven't felt short on power in lighter air either, but I do adjust diamond tension on the water if conditions change drastically.

Matt says you can get them result through spreader rake, and through diamond tension, and yes you can flatten the sail dramatically, (and if you go real crazy you can make the top really fall off), but I was really hunting for power when the wind lightened up with those settings. I think I took it to 42 on a black Loos gauge, and something like 2-1/4" of speaker rake. It was an obscene amount of prebend. Hindsight I don't think any of those numbers is safe for that mast, but it did survive.


When I started to sail A class I went through a bunch of sail iterations. I am short and light, so overpower is a big issue, same as the uni guys experience with the F16.

I had several different cuts made built out multiple different bend mast and borrowed a bunch of others trying to find a formula that would make me competitive to weather once the winds started up over 12. After a bunch of money and effort, I realized that changing sail cuts made approximately zero difference in how I was performing.

Once you sail is pulled flat, whether is early or at the end of your Cunningham range, it makes no difference. How you run the sheet and tiller to maintain hull speed makes all the difference. Apparent wind is your friend just like the problem TEH was having in another post.

I would love to sell everyone some dedicated equipment and the sail makers would too, but if you really want to play with it, creating a bit more prebend will flatten out the bottom of you sail earlier, and some stiffer battens will work the same in the top. 20 minutes of time and a few battens are cheap. Problem is a flat sail to start then has limited power in the light stuff. I have been very happy with the standard sails we have already. The very bendy masts used on the F16 allow you to have a very full sail and within the range of control, I can still pull it board flat. If you still need less power then really you just need less sail

Re: vmg for uni [Re: Matt M] #231987
05/05/11 01:36 PM
05/05/11 01:36 PM
Joined: Jan 2009
Posts: 5,525
pgp Offline OP
Carpal Tunnel
pgp  Offline OP
Carpal Tunnel

Joined: Jan 2009
Posts: 5,525
Thanks guys! smile


Pete Pollard
Blade 702

'When you have a lot of things to do, it's best to get your nap out of the way first.

Re: vmg for uni [Re: pgp] #231989
05/05/11 02:39 PM
05/05/11 02:39 PM
Joined: Mar 2009
Posts: 932
Solomon's Island, MD
S
samc99us Offline
old hand
samc99us  Offline
old hand
S

Joined: Mar 2009
Posts: 932
Solomon's Island, MD
What settings are people using when sailing uni upwind? I'm talking major changes-boards, mainsheet and traveler. The discussion has focused on going upwind in heavy air. Are people dropping traveler, say 3"? Raising boards the appropriate amount?

I think its harder to drive under main alone upwind, your eyes are forward, no tell tales up there to ensure you aren't pinching.

Finally, in the F18's and N20, the crew usually has the mainsheet in double trap conditions, and I usually hand it off in single trap conditions as well. They can play it properly and keep the boat moving at all times. Its simply faster, if the skipper and crew are synced. In my experience it is tougher to drive and sheet the main on such overpowered rigs than the skipper/crew combination. Bottom line-more time on the boat in heavier air.

Last edited by samc99us; 05/05/11 02:40 PM.

Scorpion F18
Re: vmg for uni [Re: samc99us] #231990
05/05/11 02:49 PM
05/05/11 02:49 PM
Joined: Jan 2009
Posts: 5,525
pgp Offline OP
Carpal Tunnel
pgp  Offline OP
Carpal Tunnel

Joined: Jan 2009
Posts: 5,525
blush My upwind performance is all over the place, from pretty good to down right rotten.

When I do have a good weather leg, I just sheet in hard and concentrate on boat speed trying hard not to let the chop slow me down. If I start playing with strings I may as well go to the beach.


Pete Pollard
Blade 702

'When you have a lot of things to do, it's best to get your nap out of the way first.

Re: vmg for uni [Re: samc99us] #231991
05/05/11 02:58 PM
05/05/11 02:58 PM
Joined: Jul 2007
Posts: 439
Memphis, TN
M
mikeborden Offline
addict
mikeborden  Offline
addict
M

Joined: Jul 2007
Posts: 439
Memphis, TN
When you start depowering with raising the boards and dropping the traveler, you are going to be severely punished that way cause the 2-ups won't be doing that. They have enough leverage to keep the boat down, especially if they know how to drive in the heavy stuff.





Viper USA 132

1984 Hobie 18
Re: vmg for uni [Re: mikeborden] #231993
05/05/11 04:05 PM
05/05/11 04:05 PM
Joined: Jul 2007
Posts: 439
Memphis, TN
M
mikeborden Offline
addict
mikeborden  Offline
addict
M

Joined: Jul 2007
Posts: 439
Memphis, TN
I have been using a sloop sail and I have the boat pretty powered up...

37mm of spreader rake
32/500lbs on the diamonds.

At Sprinfever on the first day of racing when there was a little more than 10kts, I tightened by diamonds close to 35, in lbs I don't know what that is, but there were couple of times I had to come off of the wire on the first race cause I was way too depowered with that setting. I was sheeting in as hard as possible and that made it worse. I also didn't do well in that race. After that race, I loosened my diamonds back to about 32 and the boat had more power and I could trap the whole time going upwind. I also did better in that race. I might have been back in the pack, but I wasn't that far behind at all.

I do have stiffer battens up top, but from that regatta, I don't think it's that hard to depower the Sloop main for a UNI rig. Of course, that's up to a certain extant anyway. After 15kts, you need less sail area on a UNI rig to be almost as fast as the sloops.

At least that's my opinion anyway. smile

So don't SHOOT ME! smile


Mike


Viper USA 132

1984 Hobie 18
Re: vmg for uni [Re: mikeborden] #232034
05/06/11 02:51 PM
05/06/11 02:51 PM
Joined: Jun 2001
Posts: 3,116
Annapolis, MD
Mark Schneider Offline
Carpal Tunnel
Mark Schneider  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 3,116
Annapolis, MD
West River event had a different winner in each of the first 7 races.. 2 sloops... the rest uni.

The wind speed was reported at Thomas Pt. 1.5 miles away 12 to 15 sustained gusts to 19

Windspeed is not accurate on day 2. race 7-10)

West River F16 results

ask these guys for their 2 cents.

A cats worry about drag.... after you blade off the power... you still have drag to deal with. if you don't have the proper uni sail.. you probably can't sail to the number. It's much harder to make the A cat go fast then a sloop boat.


crac.sailregattas.com
Re: vmg for uni [Re: Mark Schneider] #232038
05/06/11 03:21 PM
05/06/11 03:21 PM
Joined: Jul 2007
Posts: 439
Memphis, TN
M
mikeborden Offline
addict
mikeborden  Offline
addict
M

Joined: Jul 2007
Posts: 439
Memphis, TN
Are you saying the top two UNI guys in this race were using a UNI main?

I know Ed has a different main that didn't come with the boat, so I'm assuming he has a UNI main.

The others I'm not sure about.


Mike



Viper USA 132

1984 Hobie 18
Page 1 of 2 1 2

Moderated by  Damon Linkous, phill, Rolf_Nilsen 

Search

Who's Online Now
0 registered members (), 428 guests, and 75 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Darryl, zorro, CraigJ, PaulEddo2, AUS180
8150 Registered Users
Top Posters(30 Days)
Forum Statistics
Forums26
Topics22,404
Posts267,055
Members8,150
Most Online2,167
Dec 19th, 2022
Powered by UBB.threads™ PHP Forum Software 7.7.1