The weight difference is really noticeable with the code vs afs foils too. Some of this is likely the UHM carbon in the AFS foils but I agree, the fuse is really small and clean on the AFS.
The only thing that leaves me unsure about the afs is the non monobloc front wing for the Enduro. I mean youād think monobloc is where everything is moving towards if you want the best performance. Non monobloc means lower cost and more portability in exchange for a compromise in the performance.
1 Like
Itās true, I prefer monoblock. However, thereās a lot of foilers who really want it to breakdown for travel. So, it is what it is. Iām hoping for a larger Ultra myself. I love the 750 but a 950 would be ideal for the lighter days here when I just want to glide. Having the full monoblock UHM foil construction is such a gem in the silks and ultra, looking forward to more options with it in the future!
Great summary, thanks for sharing! Picking apart failures is super tricky, Iāve seen a few Axis setups fail due to the wrong screws being used, they now label the holes which is a nice idea, most should follow suit or make it easier for customers.
By my understanding, this is why this style it canāt be an industry standard, there is so much variance in manufacturing across brands, and this style doesnāt accommodate variance in tolerance. I had the same thing with Axis where the NLv2 was so tight it needed a hammer.
The F-one/AFS style, if made a standard, is designed to accommodate higher variance?
Off topic 1:
Here is a nice picture (from Seabreeze) of the new Duotone connection, looks relatively very complex but I suppose quite sensible, and tested.
Off topic 2:
Does anyone know the correct torque for AFS? Iāve been going quite a bit higher than on Axis, not sure if appropriate
I was told by AFS directly to just crank it down tight, no torque spec was given.
Jondrums, thanks for the effort of the sketch, but you cannot ignore the other surfacesā¦force resultants creating countermoments of surfaces not in the cornersā¦just like dontsink said, the conical connection has 3 surfaces creating counter momentsā¦the screw is just stressed in tension/ there to hold the connection in place. as long as the mast top is in the fuse socket without play thereās no moment or shear on the screw even if loose. with the other system as soon as the screw is not fully tensioned it will be subject to bending and shear. it may have other advantages but just from a mecahnical standpoint the form closure conical connection is stronger.
3 Likes
Thanks for the thoughtful response. I agree that the cross-sections I posted donāt tell the whole story! Especially right at the front of the cross section, the reaction force at the top of the interface can add meaningful stiffness.
It is worth noting that the AXIS interface is NOT conical, it is straight sided. The CODE appears to be slightly conical. I think conical is superior in some ways, problematic in other ways. If the tolerances arenāt right we could have a negative structural result. But generally conical will almost always be better than straight sided I think.
I want to be clear (because people use strength and stiffness interchangeably, which is incorrect) I am speaking about stiffness, which is what matters as long as we arenāt breaking things.
The k2 connection is tight conical as well, and often Iād think I had tightened the bolts enough, but riding it would tighten the connection but loosen the bolts. That would also create random shim angles. So maybe not so much strain on the bolts, but not ideal.
1 Like
Interesting development from Starboard. Watching their team riders easily win a 15km pump foil race on 88cm masts (the longest masts there) at Crozon race gives me confidence in their engineering capabilities, but this is pretty ambitious
1 Like
I agree, ambitious if they are hoping for the whole industry to jump on board. That will be a challenge. However, I think itās awesome that they are sharing their design. Have you by chance ridden any of their stuff yourself? I donāt think Iāve seen any at the river yet.
It sounds obviously good to be able to mix and match but more modularity is usually worse at performance, usability, and cost. Whoās asking for this trade off?
1 Like
No, just was amazed at how long the masts were that they were winning on. I had a good look at them, seem very solid, pretty industrial looking shapes
I doubt your picture represents anything realistic.
I ride both (Afs, and Axis), I have no ambassadorship, or any brand to defend.
Iām just trying to suggest a rational look at things.
At all time, in any scenario, the contact surface to transmit the load is much more important in the Axis/Code/Uni design than in the AFS/Fone design.
There isnāt any scenario where the Axis/Code/Uni/Lift relies only on bolts as much as AFS/Fone.
And bolts are fairly weak compared to large carbon surfaces contact.
People who are riding both know it.
With AFS/Fone itās 100% bolts, without them, light wind is enough to make your foil fall off the mast.
Axis or Uni get stuck inside. You may even ride without bolts.
Why? More intricated contact surface, making a stronger connection.
1 Like
This distinction is 100% based on material. Socket is better with an aluminum fuse but with carbon the socket will flex and crack. The AFS style is better for a carbon fuse.
6 Likes
OK. This is the fun of online chats like this. I generally donāt agree with anything you posted, but thatās cool - we can disagree.
Good point, this is a major factor pushing in the two directions. But it should be noted that Lift and Code have been doing ācarbon fuseā with the socket joint fairly successfully.
My cabrinha fusion is all carbon with socket.
It has not cracked and it feels pretty rigid to me.I think they can be at least equal in strenght and stiffness.
But i agree 100% with FoilFondler, conical sockets can create random angles and loose screws as dirt/salt dissolves in the session.
A Takuma carbon V1 i had suffered badly from this.
Very annoying ,i am OCD about shims and angles 
Just for that i would vote for flat connections.Reduced fuse section is a bonus.
As a heavy rider 95kgs Iāve been through most of the brands (Armie, GoFoil, Code, Uni, Axis) and all of them I have felt some weird movement when riding, not every session but quite regularly, like something is lose or readjusting. Iād check the front wings and screws all tight. It is very offputting and does not instil confidence in the system. I attribute it to the mast/fuselage joint. I am moving to AFS so I will be able to determine if the mast/fuselage joint is the problem.
Everyone knows that the joints with the U shape wear overtime and become looser and rely on the bolts more and more and the fuselage ends up crackingā¦
Itās only fun if you can back up your disagreements with logical argumentsāotherwise, itās just noise and beliefs.
My only objective is getting closer to the truth.
This weekend I was at the Boot in Dusseldorf.
I chatted with about ~10 foil designers and Iām always asking the same question about this design part.
Most brands using the U connection (Axis, Code) comes up with a similar explanation: the idea is to maximize contact surface to better transmit forces between the mast and the wing. It also allows to minimise the load on bolts, and their receiving end, the bolt insert.
Most brands using the flat connection design (Afs, Fone, Ensis, Indiana) answer the same thing: āit is a classic woodwork connectionā.
None of them can explain why they think classic woodwork connections coming from wood furniture would transfer well to carbon and high load sports.
Some add arguments such as itās simpler to produce, cheaper and it allows to get a thinner fuse.
It is not necessarily true.
Some brands are thinner, some are thicker.
Code is more chunky.
Axis is thinner.
AFS is thicker than Axis all the fuselage long.
Measuring between the wing and the mast weāre getting
- Axis 11 cm diameter and
- AFS 13 cm with the mast and 11.6 even without the mast
- Code 14.3 cm
The arguments such as āit does not create play overtimeā also does not hold up under scrutiny.
Not only there is no reason why flat connections would not wear out overtime (especially in AFS which is fragile and youāre collecting carbon crumbs/grains wearing out everytime you unmount),
but in addition, due to the high load on bolts, flat connections are subject to bolts or inserts failures, making you lose your foil in the ocean.
This is regularly reported.
And loosing a $1500 plane in the ocean is much more annoying than having to put a layer of epoxy once a year to fix the potential wear of a U connection.
Again, Iām not affiliated to any brand.
I buy my foils full price, including the AFS and Axis.
I have no $$$ interest in defending a system or another.
But Iām annoyed to see the āflatā design promoted with so-called āargumentsā (āit has more contact surfaceā, āitās thinnerā, āit doesnāt wear outā) that after scrutiny seem to mostly be beliefs.
Thatās not the way to drive progress in the foil community.
4 Likes
Well, choosing a flat plane connection and designing it with 2 bolts is probably too high a risk .Loose one and the other one will very likely fail.Maybe they did it because of thin mast section?.Weight saving?.
Do not like it much.
I think Mikeās Lab uses 4 bolts?
Duotone uses 3.
My Cabrinha Fusion socket does look kind of beefy compared to that Axis.
I like the crossbolt it uses, i think it has to help a lot in preventing that socket flexing open under load.
From a fellow truth seeker, letās make sure not get too pedantic 
good vibes are important too, and assuming everyone is contributing ideas in good faith definitely helps
( we know where things end otherwise )