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Shimano Monofin

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.

trux

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Dec 9, 2005
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A friend from my freediving club, Alain Richioud, ripped off the footpockets on his Breier wing mono, and inspired by the Lunocet and the Sporasub Revolution concept with bicycle shoes, he decided to completely strip off the original footpockets, and replace them with a pair of Shimano bicycle shoes. With a help of a local metal workshop, he created quite a sophisticated construction. Below, I am attaching couple of photos of the first prototype.

You can probably see too that it is a little bit over-dimensioned, and not really streamlined, and it has also couple of other issues (for example the round stiff edge connecting the footpocket to the blade), but I was totally amazed by the quality of work.

Unfortunately Alain broke the blade during the first test session (it did not resist the pressure of the metallic edge when he pushed off the wall), so there is now a second improved and lighter prototype in the works.

The only problem is the blade. Alain together with the manufacturer already invested a lot of effort into this hobby project (with no commercial intentions), and he is now hesitating to buy a new monofin (or a blade) just for the tests. So if any of you have an old mono or a blade laying somewhere around, and would be willing to get rid of it for little or no money, it would be very much appreciated. The type and stiffness do not matter too much at this moment. If you can help, please drop me a PM, and I'll get you in touch with Alain.

 
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Ah, I forgot to tell - the most beautiful on it is that, unlike at the other mentioned fins, you can walk (or ride) in the shoes to the pool or beach, step into the fin and jump in the water. The footpocket uses the same locking mechanism as used on bicycles.
 
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hmmm very clever and nice workmanship, sorry i havent got a spare blade laying around (accept a snapped one.....)

i hope it all works wellas it is a nice design.

DD
 
I have some more details about the fin from Alain. The weight is 4.5kg complete with the blade and shoes, and it is neutrally buoyant. The second version will be considerably lighter.

I also asked if they did not consider adjustable angle, and indeed it was the original idea, but they did not want to complicate the design and manufacturing too much, so decided for a simple version first. Still, it is possible to make some adjustments by inserts under the shoe. And by this way you can also compensate eventual asymmetry - that's exactly what Alain needed because of an injury-induced assymetry.

I am looking forward to see the next version, and will report as soon as I get some info.
 
It looks like there is a lot of detailed workmanship in that hardware. It looks really nice and I hope it works out for Alain. Thanks for sharing the pictures.
 
As I told, this is a hobby project, not really a commercial one And the purpose is not really a high performance fin as the DOL-fin, but a comfortable one, which will not require permanent repairs like many traditional monos need.

Alain does not really seek beta testers (we are 50 in our club, so there are more than enough testers). What he needs is some old monofin blade
 
OK, Alain still did not find any new blade, but they've put together version 2 of the fin with a shortened blade (they had to cut off the broken part). It means the blade is now too short and too hard, but for the testing it does not matter too much.

The second version was just a quick and dirty intermediate solution, before the already designed v3 comes out, but I was completely amazed by it anyway. It is beautifully simple, very light, and better streamlined than the v1 (though the v3 will be even lighter and more hydrodynamic).

I tested it, but not being a regular monofin user, I am not a good reference. However, despite the short stiff blade I really liked it. In comparison to other monofins I tested, it was not only much more comfortable, but also better maneuverable, and the big angle felt good too.

There are some pictures and videos below, and even more in the gallery of our club. The testers are Alain himself, and Philippe. Alain has only a short experience with monofins, and the technique is also influenced by the way too stiff blade. Philippe is a more experienced with monofins, but the blade was too short and too stiff for him too. So please excuse the imperfections.




video Alain | video Philippe

I hope Alain finds soon a new blade, so that they can complete their v3. I am eager to see it.
 
Alain showed me also another intermediate version of the fin they tested last weekend. Since they do not yet have a new blade for the testing, and since the manufacturer is specialized in metal works, he thought he'd try a steel blade instead. And the results was surprisingly good. Still a bit too stiff, but they will give it another try. I am curious what it brings.

If it works, the manufacturing would be much simpler and faster than with laminated blades. On the other hand, we might see a lot of blood and freely floating limbs in the pools during training hours

​
 
What is the webbing material that was used in the fin blade?
 
I have tons of old monofins and old blades. However what little money I can get for them is not worth the trouble of packing & shipping them. However if you know someone in my area who will come and pick them up then that would be great. These include both standard and highly unusual/custom blades that I accumulated over the years.
 
Reactions: jay cluskey
REVAN said:
What is the webbing material that was used in the fin blade?
Click to expand...
It is some kind of heat-sealing plastic foil, but I did not see this version personally, so can't tell you closer. The construction was just hot-stiched in the day before testing, and it will be considerably different later.

efattah said:
I have tons of old monofins and old blades. However what little money I can get for them is not worth the trouble of packing & shipping them.
Click to expand...
Yes, I understand, and I think it is the same problem for others too, but thank you for the offer. Breier (the French monofin manufacturer) promised Alain to let him some defect blades, so hopefully he holds his promise.
 
Alain (together with the TMIM workshop) still continues to develop and test the monofin. In the meantime they created countless intermediate versions. The last weekend I saw the latest model, which is already pretty usable, and fairly simple.



I find ingenious their idea to use a PCB (Printed Circuit Board) sheet for the blade! It is cheap, easily available, and the manufactuting quality is high and especially consistent, which is definitely not the case at almost any of the monofin manufacturers building blades. People often complain the blades stiffnes, layering, symetricity and homogenity differ from one piece to another even if the order is identical. With the PCB sheet, which is just a piece of industrially manufactured fiberglass sheet, the consistency and the homogenity/symmetricity issue could be solved.

They just needed to cut the individual layers manually, but keeping the exact shape should pose no big problems.



This is not yet the final version - several other models are still in play. One with a carbon blade, and another one with a full-metal high-grade steel blade. I am curious to see them in action.

You can find more photos of the diverse previous versions here: http://cyrnea.net/gallery.html?albumid=5621530478718931425
 
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Reactions: Mr. X
Pretty sure that several manufacturers use PCBs as their base material. There are concerns over the type of resin used and it's long-term viability, but even if it does die it's cheap to replace.

Where is he getting the sheets from? I could only find small boards or industrial quantities.
 
Not sure where they take it from, but they use to work with many big industrial manufacturers and suppliers, so they have other possibilities than individuals. I'll ask where it comes exactly from.

The PCB cannot be used for monofins requiring a blade with an angle, but that's solved here with the inclination of the metallic support and the shoes.
 
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That is a nice looking swimming hole in the picture above. Where is that?
 
Interesting. I wonder if PCB board would be any good for spearfishing fin blades? :hmm
 
I think it is worth of testing - it definitely might help building quite inexpensive fins. But you would need some support similar to the one at Alain's monofin that would allow for the angle between the footpocket and the blade.
 
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