Greetings, I'm new here, so if this has already been discussed, please send me in the right direction. I have built a class 5 from scratch (off Mike Hampton's old plans-mostly) and owned two "production" boats, a US Fed 5 and my current boat a New Zealand Rocket. I would really like to design and build another, but would rather not just exactly copy something that exists.
All the really fast boats seem to be of the frame-over-seat variety, whether they race on the beach or dry lakes, but the way the front suspension/strut connects to the 'Y' part of the frame and to the seat seems to vary a lot. The "why" of those differences intrigues me.
Blake
US319

This could end up somewhere as there has not been a lot of discussion around y framed yachts and different frame designs.

Some of the discussion has been around how much they cost but I and I think Clem would dispute this as the class5's I have built have cost no more that any other yacht, The main cost has been the sail ,mast and pulleys.

What has been lacking is plans ect. I would post mine but they are full scale on my shed floor.As for the front setup I have tried both the french and new Zealand type setup, I think the Kiwi design may have a more positive steering than my french design

I am going to try a wheel barrow wheel to see if that improves the steering (only a problem in high wind conditions)
Cheer
aus230

Seems like the goal of the chassis is to keep the wheels pointed pretty much in the same direction (avoiding toe change and self-steering) when the sail loads up and tries to bend things out of shape.
Both my low-frame yachts failed at this in ways I could watch while sailing. With the mast step right on the main frame a big puff (or a strong steady wind) would twist the frame and lean the front wheel leeward if I didn't correct. If I did correct it looked seriously crossed up and had to be slowing things down.
The NZ rocket (high frame) seems better; Bill's design supports the mast on a different tube from the steering. At first I thought that was only for "suspension," but maybe it allows the mast to twist the main frame, without twisting as much on the tube that holds the front wheel.
I notice that AUS230 (at least the version that is the current avatar) and Clemco's NZ701 have the high frame, but the mast is on the same tube as the front wheel. How does that work out?
The latest French boats, Airtrack and Plume seem to use the same concept as my Rocket, although the details are pretty different. Is it the Glens that have tubes on either side of the mast going to the front wheel (like older Airtracks)? It seems like that would really separate the sail forces and the steering ones.
Non-design question: is YOTT a particular design or does it refer to a group of slightly similar yachts?
Do the French or British folks ever comment here?
Has anyone collected photos of frame designs (for this type of yacht)?

The only steering difficulty I had with my Rocket design was in the hard turns
around a mark Leaning forward in the seat to put more weight forward and keeping
the sail sheeted hard in helped quite a bit but the ribbed tyre helped the most
At all other times the yacht has always been OK
I have always sailed the Class5 on sand
YOTT as I understand it means [ Y over the top ] to define the frame type

Ha! You might have started something here!
Lefroy minis and the like would be TUTBs then?
Back to class5 I have a suspicion that the only reason for the Y frame is because of the tube axle rule and to get the flex the axles must be longer
I am sure someone out there will be able to tell us
Also I have heard it said that the OTT design came about to clean up the underside when going through puddles etc

The acid test ! You are the man Vic The barrow wheel wont look as good tho to my eye

Lake Lefroy mini"s are SOTT's Seat Over The Top (not refering to the pilots drinking habits) [}:)]

to continue the silliness: my US fed 5 was YITS 'Y' inside the seat...

Ivanpah is on the California Nevada border about 30miles from Las Vegas.

sorry, I'm in Albuquerque,New Mexico. Shouldn't reply to posts read without my reading glasses All our closer dry lakes are currently politically unavailable. So Ivanpah seems to work, despite the 10 hour drive.

I tried the barrow wheel on aus230, The results where that the steering was more positive in sharp turns but I will be replacing it with the 20" setup as I found that it made the front end very rough and was the first time that it was not smooth to sail I have a spare maxxis miracle tyre to try (as hiko mentioned) So I will see how that goes.
Cheers
aus230

blake52 said...

sorry, I'm in Albuquerque,New Mexico. Shouldn't reply to posts read without my reading glasses All our closer dry lakes are currently politically unavailable. So Ivanpah seems to work, despite the 10 hour drive.

Albuquerque,New Mexico. That is "Breaking Bad" country. If you went out to one of your dry lake beds there with a motor home you might have the DEA swarming all over you. Say gidday to Walt and Jesse for me.

Cisco,
I'm not a big TV watcher...I had to look up Breaking Bad...we have had some strange plane landings on our dry lakes and a small tornado, our events, 30 miles from Mexico, were often visited by border patrol agents and homeland security... one even went for a landsailer ride... but our conflicts are mostly with cows, cars, dust storms and bureaucrats of the unarmed variety.

I posted a link to this forum on the FISLY Class 5 forum. Maybe there will be some crossover.

blake52 said...

to continue the silliness: my US fed 5 was YITS 'Y' inside the seat...

Hmmmm! Sounds like a New York Jew to me. Schmuck, Putz, Yid "YITS"[}:)]

27 Fed 5 US version made by SR Marine, 4 NZ Rockets, soon 2 Airtracks like the ones they ran in the Worlds, 3 Seagull Maxi Sports, a handful of Pacific Magic / Hondo Ratracer derivations, a NZ Fed 5, a couple of Promos, and a few home-builts that probably qualify. And, no doubt, some I don't know about, particularly on the East Coast (I read somewhere int his forum that someone was building a YOTT on the East Coast).

Here's a close up of the front end. There is a Nolathane bush for a damper in the pivot.
The pivoting lever has a bunch of cut up rubber inner tubes wrapped over it. If I want it softer I just roll off a couple of the tubes. I find it works best to have it almost solid, but it still flexes when I hit something hard. Also good when you get hit by a strong gust. Tends to soak up some of the energy and releases it once you have gained control. It has saved my ass many times.