Reviews about C4 Fuego 30 T700 VGR Carbon Fins
C4 Fuego 30 T700 VGR Carbon Fins:
Top fiber quality : MEGAFORCE T 700
In the fins FUEGO VGR the use of the new fibre MEGAFORCE T 700, HT type yarn (Hight Tensile), allows, thanks to its resistance of 40% more in comparison with the standard yarn T300 and the same elastic module (Tensile Modulus), to considerably improving the resistance to break of fins.
In order to understand which importance has, with the purpose to resist breaking, a fibre with more resistance and with the same elastic module, as MEGAFORCE T 700, it is enough to consider which are the stresses and how they are distributed. The beginning of a blade break occurs when, for too much bending, the material is stressed with a least curve ray, exceeding the resistance values.
If we suppose a blade section and the stresses on the different layers or sheets are analysed, we discover that during the bending the exterior sheet has a curve ray larger than the sheet that is on the internal side of the blade. The external sheet is so subjected to bending and traction, its opposite side to bending and compression. The sheet that will be placed in the middle of the section will be stressed only to bending.
With these stresses, the blade will start breaking when the external layer, the one more subjected to traction, stands no more applied stress. If this layer or sheet has a resistance higher of 40%, it will occur that it starts breaking for traction charges higher of 40%.
It is therefore essential that these layers or sheets (the ones external of the blade) have a strong resistance. The resistance of a sheet is improved through two parameters: the physical dimension of the blade (large and/or heavy clothes) and yarns with high resistance, as MEGAFORCE T 700 .
The yarn MEGAFORCE T 700 has a percentage stretch to break of 2,1%, in comparison with 1,5% of the standard T300. This improves the flexibility and the resistance to break too; thanks to this a more accentuated fold of the fins can be reached.
It is important, both for resistance that for bending, that the yarn MEGAFORCE T 700 has got a standard elastic module as T300. A higher elastic module would make the fin very stiff. A stiff fin doesn’t bend and therefore it would not work, as it ought to do. In order to reduce the stiffness of the blade and allow its bending, thinner sheets (light cloth) and so less resistant should be used. This is the reason that makes unsuited the use of yarns HM (Hight Modulus) and light clothes for the manufacture of fins.
The carbon blades C4 are composed by more fibre layers and have a progressive lamination to get the required and needed parabolic bending curve.
Among the many possible ones, the ideal parabolic curve is the one that water density naturally imposes to fish, this is the more functional for our purpose. If we notice a swimming fish, we will remark as its head (for us the foot) is substantially firm, while the body is bending, more and more approaching to the tail, in an always more marked way.
The bending line of the fish is so parabolic, also if at a summary look it seems only the tail is bending. In the fish, as in the fin, all concerned surface is bending, less towards the head (our foot) and more in the last part of the tail (the blade end) with a bending typical of parabola (a simple parabolic function is x = y2).
If we consider a blade, as it was a shelf embedded in the foot and subjected to a uniformly distributed charge, we will remark that the section further and further from the foot bend only if the previous ones support them, that is the first ones should bend less.
A blade visibly bending next to the feet will not allow to the last stroke to work in the best way, getting so only a partial exploitation of its dimension features.
So, this kind of blades cannot work fully in a parabolic way, it is wrong to say it, but on the contrary in a quite uniform way and this is the opposite of a common believing supported by summary observations and bad information.
A blade working with a quite uniform bending surely doesn’t follow the fish swimming, to which it is certainly not taught how to bend in an efficient way the fins.
The blades C4 FUEGO VGR stretches until the foot heel, allowing so the most energy.
The blades C4 FUEGO VGR have the most stressed section increased of 15%. Furthermore the position of the fastening screws has been expressly moved away from the blade fold to make void the effect of hole notches. The combination of the increased resistant section, of the lack of holes on the stressed section and of the change of lamination of the blades C4 FUEGO VGR allowed the reaching in laboratory tests of a resistance to break more than 40% in comparison with standard type blades.
The very good sport results got by the blades C4, since 1990 until today, are the sure guarantee of the performances of our products and of the correctness of our technical choices.
In FUEGO VGR the flap shape of the blade end (patent C4) allows better parabolic bending curves, less energy absorptions and more efficacious water flows detachment from the blade (for more information see the page fins C4 FLAP).
VGR - Variable Geometry Rails
The water rails, invented by C4 in 1994, play the role to control, canalising it, the water on the blade. They make the swim with fins stable, the fin moves as led on two rails; the performances are enhanced by the total lack of "derapage" effect.
In plain breath-held diving, where the performance is executed in controlled conditions, in quiet waters, in a straight path with constant charges, the performance is obtained with the matching of least energy consumption and highest speed.
The requirements for fishing are different, because an easy handling, a sudden spring and variable charges, due both to fishing needs and changing sea weather conditions, are required.
Therefore the main thing requested to fins is their adaptability to the changing work conditions to which they are subjected. As we know, the improvement of performance is always reached by adjusting in specific way the features of the tool, to the action needs.
Changing needs require modifications in the equipment. Only one thing good for all means to be satisfied with common performances and this is not our philosophy.
The water rails VGR (Variable Geometry Rails) let in a new concept in the system of control on the amount of water worked by fins. By them the canalisation of water flows is progressively modified according to the area and the fold of the blade, improving the performances.
We know that, owing to the move led by the foot on the fins, the speed of water running on the blade is increased, passing from the foot to the blade end. It is this that provokes the propulsory push of the fins. With the water rails VGR, water amounts worked are progressively modified, following the speed changes of this in the progressive sections of the blade.
A further advantage given by the water rails VGR is they take at work a special shape of the “L” sections, strongly reducing the rips between the layer of moving water on the blades, in comparison with the static one of the sea.
The water amount worked by the water rails changes according to their dimensions. Low water rails work little water, if high they work more.
With the same conditions of materials, surfaces and applied energy, more is the worked water, stronger is the push. It is for this that long blades pushes more than short ones, because they work more water.
With the same conditions, the worked water becomes the one controlled by the water rails, that are useful the largest possible, to work the maximum of water, this consistently with the elastic response of materials, hardness, geometries and dimensions of the fins. Task of the designer is to amalgamate materials, stresses and dimensions to get low consumptions of oxygen and high speeds.
Therefore the water rails VGR have the largest possible dimensions for each section of the fins, to make the maximum possible quick the worked water amounts.
What is useful, where and when it is useful, it is so that higher speeds and energy saving are obtained, as it is with the water rails VGR.
Energy transmission: foot – blade position
What is the best position for the foot related to the blade, and vice versa-
Answering this question calls for a careful observation of strain application and of how movement is executed, both for the foot and the blade.
In the fins, the shoe defines the reciprocal position of foot and blade, the components it connects.
Some technical features affecting the reciprocal foot and blade positions are unavoidable, others are modifiable.
For man it’s natural to lean against the lower part of metatarsus for applying an effort, like for example against bike pedals, climbing a staircase steps or running. That spot of the foot is where it’s possible to naturally apply maximum strength and maximum movement, that is to exert maximum work with legs (work = force x movement).
The fin blade is mechanically classifiable as a bracket submitted to a load homogeneously distributed. So it’s possibly to identify, depending on bending, a centre of gravity point of the load applied and its distance from the bracket joint position, in our case where the blade bends, exiting from the shoe.
The fulcrum effect to which the load produced by blade movement is applied can be computed as the distance between the projections, on the theoretical advancement axis in a submerged diver, or longitudinal axis, of the metatarsal points and the gravity point of the load applied to the blade. This effect is in direct proportionality to the resistance a diver has to overcome in moving the blade.
The lesser this distance, the lesser the effort. In C4 FUEGO VGR, with the foot advanced on the blade by 7 cm (compared to standard foopocket) the reduction of the fulcrum effect is above 20%, with all the following advantages in reducing the energy required.
The stiffness variation between 25 and 30 blades, for example, it’s almost 15%. So using FUEGO VGR 30 will require an amount of energy similar to that required by a FALCON 25, with undeniable advantages in acceleration, speed and safety.
Hydrodynamics: blade position and angle
Minimum hydrodynamic resistance is obtained when a diver, in vertical position, head up, with completely extended fins, observed from a lateral point of view, has in a single axis all articulation theoretical rotation centres: hip, knee, ankle, metatarsus and fin blades.
This is possible only if the blade is placed as in C4 FUEGO VGR, just under foot metatarsus, with the appropriate wide angle, over 23° in C4 FUEGO VGR.
On the opposite, traditional footpockets and/or blades with narrower angles, force fins away from the body axis. The diver will be compelled to arch his/her back when swimming (by necessity a symmetrical movement) for moving in a straight line.
Arching the back increases the diver frontal section and increases the hydrodynamic resistance. Both the arching and the increase of the resistance subtract energy, detrimental on both dive time and safety.
When the angle between the diver axis and the fins axis is too wide it’s possible to have damages to articulations as knees and ankles. It’s plainly impossible with C4 FUEGO VGR; the ergonomics is at its maximum.
C4 FUEGO VGR fin is produced taking in account hydrodynamics requirements both because it has thoroughly rayed shapes and a close outline in its shoe, and because it lacks side stiffeners. Without side stiffeners it has been possible to distinctly reduce the shoe frontal section, in the same way reducing related hydrodynamic resistances.
Right and Left anatomic shoe.
How well a fin fits is an essential feature to the effectiveness of it. The shoe, not anymore simply footpocket, is the primary component in the cinematic chain of energy transmission from the foot to the blade: better the connection, more energy will be transferred to the movement.
A freediving fin has an optimal performance if the shoe has good ergonomics, if it fits perfectly to the foot. For this reason we produced anatomic right and left shoes, with a customable regulation of the shoe lacing.
A single footpocket, somewhat constricting the foot or letting it free to partially move inside it, has been so far the usual conditions every diver had to deal with, choosing between how much pain to endure or how much energy to disperse.
C4 FUEGO VGR simply eliminates at the origin all these problems: they significantly improve how well it fits, giving more comfort and effectiveness to the athletic motion.
For obtaining the best ergonomics, C4 shoe has been shaped from the best running shoes, revised to fit freediving divers’ requirements.
Optimal C4 shoe anatomy allowed the use of a strong polymer, so guaranteeing an excellent energy transmission without reducing comfort.
The shoe has been planned with different thicknesses, obtaining different resilience in various portions and optimizing energy transmission.
The choice to produce shoes without traditional side stiffeners moved the fins centre of gravity toward the foot, making them significantly lighter when swimming.
Energy absorption due to side stiffeners in traditional fins has been measured in tests developed in the Engineering Department of Padua University, and it resulted to be of 55% in the hysteresis loop. In C4 FUEGO VGR this energy is not squandered in the shoe, with an obvious benefit in performance.
It’s easy for all to appreciate the superior comfort due to the anatomic right and left shoe compared to the traditional fin with an identical footpocket for both feet.
It’s easy to obtain a fine custom adjustment of the shoelacing, using the elastic strings C4 FUEGO VGR are provided with. This gives the best possible fit for every foot. It’s a system very similar to the one we’re used to with land shoes: right and left shoes, with laces to tie them up.
For the foot, underwater or on land, comfort and energy transmission are exactly the same. Having the possibility to “custom” adjust the attachment pressure is the maximum a freediver could ask to his/her fins!
The lace operates on five points and the adjustment has to be done only once, on land. When decided the attachment pressure and tied up the lace with a knot (see assembly instructions) the diver can forget about it and use C4 FUEGO VGR exactly like all other fins, putting them on and taking them off like it’s used to.
Thanks to the possibility to loosen and tighten at will the shoes it will be possible, changing only the laces, to use thicker or thinner socks, adapting C4 FUEGO VGR to the vagaries of temperature seasons.
This system of adjustment, with an elastic lace, has been selected after testing countless solutions. Zips, buckles, numerous kinds of fastenings, Velcro: no one of those, for a multiplicity of reasons, offered better results than elastic lace.
It’s a solution simple, practical, easy to cope with even if there’re problems in a far away island, it’s enough a piece of rope. It’s not metal and it will not rust, it’s not a device and it’ll not get stuck, it has not springs, it’ll not open by accident, it does not carve the shoe polymer, it’s very light, it spreads out the pressure onto five points, allows an elastic distribution of effort, it’s truly reliable, it’s an extremely “marine” solution and it’s really inexpensive, a good thing above all this.
If the lace breaks up when diving the breaking point will be forcedly in a stretch of it. The friction the remaining portion of it still exerts on other insertion points will prevent the sudden unfastening of the attachment: the diver can so continue to swim in great safety.
C4 carbon blades are composed by many layers of fibers and have a progressive lamination for obtaining the required parabolic bending curve.
Being bended, external layers are submitted to biggest strains. Therefore the whole blade resilience to the start of breaking greatly depends on the external layer resilience and the blade section involved.
C4 FUEGO VGR blades have section resilient to breaking increased by 15%. Moreover the position of fastening screws has been appositely moved away from the blade bend so to cancel the effect of the holes drilled in it.
The combination of increasing the resilient section, of non drilling holes in the section under strain and of altering the blade lamination, allowed, in lab tests, the reaching of fracture resilience better than 40% compared to C4 Falcon blade, already so many times put to test.
The excellent sports results obtained with C4 blades are a sure guarantee of performances by our products and suitability of our technical choices.
C4 FUEGO VGR blade prolong till the heel so to assure maximum energy transmission. Blade measures are 800 x 190 mm.
Traditional blades are not compatible with C4 shoes, first because the joint is different and second because they’re not resilient enough, having been planned to use with side stiffener footpockets.
C4 FUEGO VGR are assembled with mounting screws, without any glue so to have the best portability.
C4 shoes right and left, are provided in five sizes:
European sizes: 39/40 - 41/42 - 43/44 - 45/46 – 47/48
US/Canada sizes: 7-7½ - 8-8½ - 11½ -12 - 13-13½
UK sizes: 6½-7 - 7½-8 - 8½-10 - 11-11½ - 12½-13
C4 FUEGO VGR 25 soft 800 x 190 mm
C4 FUEGO VGR 30 medium 800 x 190 mm
C4 FUEGO VGR 40 hard 800 x 190 mm
All the C4 products are made 100% with carbon tissue MEGAFORCE T700
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Barbatanas c4 fuego 30 t700
Gostaria de saber se vale realmente a pena investir nas barbatanas c4 fuego 30t 700!!E en relacao aos tamanhos tenho algumas duvidas, será o tamanho a usar igual as beuchat mundial competitiom??? 43/44 Obrigados...........