Les réalisations Le Vacon

[MIMI 25]

Enlève moi ce WWW.com,un jeu de direction Chriss King et je t'en commande un de suite
Il est légèrement slooping
A+

[levacon]

QUELQUE PETIT DETAIL EN PHOTOS

JP

[levacon]

Enlève moi ce WWW.com,un jeu de direction Chriss King et je t'en commande un de suite
Il est légèrement slooping
A+

Bonsoir

Mimi

sploping 40mm

je peux vous en faire un en 1/8eme et jeu de direction Chris king

JP

[christophe51]

Enlève moi ce WWW.com,un jeu de direction Chriss King et je t'en commande un de suite
Il est légèrement slooping
A+

et voila une commande de plus pour jpl

[MIMI 25]

C'est vrais,je ne le cache pas,mon prochain cadre sera un Titane Levacon
J'en ai d'ailleurs déjà parlé avec l'interressé.
A+

[carbon_928]

C'est vrais,je ne le cache pas,mon prochain cadre sera un Titane Levacon
J'en ai d'ailleurs déjà parlé avec l'interressé.
A+

Faut arrêter de déconner les gars, tout le monde veut un Levacon depuis que le poste est ouvert!
Moi qui aurrait bien voulu m'en payer un aussi histoire de ne pas avoir le même cadre que tout le monde, c'est raté!

[stam]

Pinaise, Jean-Pierre va devoir embaucher et former un soudeur... !
J'espère qu'il ne mettra pas son nom à lui sur les cadres

[levacon]

BONJOUR

Stam

comment vous trouvez le dernier sorti ?

JP

[fatmatt]

Le cadre est beau mais les périphériques ( une foi s de plus et j' imagine que c' est dut à la demande du client ) estompent notablement la qualité du vélo . Lorsque mimi25 aura le sien , je pense qu' il y aura une bien plus belle vitrine

[MIMI 25]

Ne me faite pas dire ce que je n'ai pas dit.
Je n'ai pas commandé de titane,pour le moment, mais précise que mon "prochain" cadre sera un Levacon Titane
Par contre merci pour la confiance que vous me porter sur le montage de mes bécanes et mon goût
A+

[rickyfirst]

QUELQUE PETIT DETAIL EN PHOTOS

JP

Un bague conique sous la potence serait nécessaire au lieu de la 'simple' bague cylindrique. Esthétiquement, la rupture entre la partie supérieure du JDD et le pivot de fourche n'est pas belle.

[stam]

BONJOUR

Stam

comment vous trouvez le dernier sorti ?

JP

Sur le montage... pas mon genre !
Je ne suis pas fan du combo cintre/potence, ni du jdd intégré (un petit C King pour moi ), ni du pédalier Shimano, ni des Ksy....
Sinon le cadre, comme d'hab', je trouve ça nickel et je trouve de plus en plus d'intérêt à ces tiges de selle intégrées, ça le fait bien sur un titane.
A+!

[daddyjulio]

bonjour à tous,
après une lecture de ce sujet et d'autres sur différents forums je me suis décidé pour un cadre Titane de chez levacon. Je possède un cadre vtt titus eleven qui m'a seduit et donné envie de passé en titane sur route, je roule actuellement sur un Time VXR qui est très bien et que je conserverais.

Alors je compte voir avec CLV pour un cadre avec tige de selle intégré TB3, un jeu de direction 1. 1/8eme pour un CK rouge et un sloping, je compte le monté en sram red mais bon d'ici là ( le delais est pour juillet car rendez vous en janvier) ...

Encore 8 mois à attendre.

Ce delais va me permettre de réunir les fond pour selectionner et acquérir des composants pour en faire un très beau jouet (à mes yeux).

[Rolo Tomasi]

Alors je compte voir avec CLV pour un cadre avec tige de selle intégré TB3, un jeu de direction 1. 1/8eme pour un CK rouge et un sloping, je compte le monté en sram red mais bon d'ici là ( le delais est pour juillet car rendez vous en janvier) ...

J'ai également commander un cadre chez CLV, j'ai craquer pour un set de tube Reynolds 6/4
Je vais prendre aussi un jdd classique (CK rouge !!), équipé sram red, géométrie slooping et certainement un boitier de pédalier BB30, j'hésite pour la tds intégrée, je crois que je préfère une belle tds Moots layback ... à suivre

[daddyjulio]

Alors je compte voir avec CLV pour un cadre avec tige de selle intégré TB3, un jeu de direction 1. 1/8eme pour un CK rouge et un sloping, je compte le monté en sram red mais bon d'ici là ( le delais est pour juillet car rendez vous en janvier) ...

J'ai également commander un cadre chez CLV, j'ai craquer pour un set de tube Reynolds 6/4
Je vais prendre aussi un jdd classique (CK rouge !!), équipé sram red, géométrie slooping et certainement un boitier de pédalier BB30, j'hésite pour la tds intégrée, je crois que je préfère une belle tds Moots layback ... à suivre

Je suis aussi calé que bon nombre de forumeurs présent mais si j'ai bien compris le 6/4 est plus "dur" ??
Par contre je suis pas convaincu de l'usage d'un boitier de pédalier BB30 car j'ai pas une énorme puissance a faire passer.

[Rolo Tomasi]

Je suis aussi calé que bon nombre de forumeurs présent mais si j'ai bien compris le 6/4 est plus "dur" ??
Par contre je suis pas convaincu de l'usage d'un boitier de pédalier BB30 car j'ai pas une énorme puissance a faire passer.

Pour le 6/4, la limite élastique est plus élevée donc le cadre devrait être plus rigide mais des spécialistes du titane pourraient répondre plus précisément que moi. La rigidité n'a pas été la seule motivation, je dois bien avouer que je ne suis pas insensible au coté collector du 6/4 Reynolds seamless .
Pour le BB30, je n'ai également qu'une modeste puissance à faire passer mais je pense que le BB30 à toutes les qualités pour s'imposer comme le nouveau standard (bien que le fait de ne pas avoir été proposé par shimano soit en sa défaveur...), enfin, on verra bien.

[pnoe42]

Un extrait du site de seven pour ceux qui comprennent l'anglais qui est particulièrement intéressant concernant l'intérêt ou pas du Ti6/4 par rapport au 3/2.5 :

Types of Titanium
In addition to unalloyed titanium, which is called commercially pure or CP, there are two alloys commonly used in the cycling industry today: 3AL-2.5V and 6AL-4V.


3AL-2.5V
3-2.5 titanium is an alloy consisting of 3% aluminum, 2.5% vanadium, and 94.5% pure titanium. The properties critical to bicycle tubing are best served by a high quality 3-2.5 seamless tube. Excellent fatigue life, property consistency, form-ability, and corrosion resistance are but a few of the reasons 3-2.5 is still the premier frame material.

In the U.S., bicycle frames are commonly manufactured using 3-2.5 certified to either an ASTM B-338 or a sports grade specification. ASTM B-338 meets all Aerospace Material Specifications for hydraulic tubing. Sports grade, certified according to a less stringent set of chemical and mechanical specifications, is typically less expensive.

Some builders may use surplus material or "scrap", which meets neither aerospace nor sports grade specifications. Certification is not available for scrap, making it impossible to determine whether the material is of inferior quality.


6AL-4V
An alloy of 6% aluminum, 4% vanadium, and 90% titanium, 6-4 titanium offers some very favorable raw material properties, which is why Seven uses it to fabricate dropouts and other frame parts. One of the properties that makes 6-4 an optimal material for dropouts is its toughness. But this toughness also makes it unattractive as a material from which to make tubing. Applying the techniques used to draw 3-2.5 tubing to 6-4 tubing costs much more and wears tooling very quickly. In addition, tube wall consistency, concentricity, and finish quality—both inside and outside—are limited. At the time of this printing, no U.S. mill offers seamless 6-4 tubing. However, some do offer 6-4 seamed, or welded, tubing. Applying the techniques used to draw 3-2.5 tubing to 6-4 tubing costs much more and wears tooling very quickly. In addition, tube wall consistency, concentricity, and finish quality—both inside and outside—are limited.

Two major issues prevent Seven Cycles from favoring this method of tube manufacture. First, seamed tubing is fabricated by rolling 6-4 sheet into a tube shape while simultaneously welding the seam that is created in the rolling process. The result is a tube that has a welded seam—a potential failure point—along its length. This seam acts as both a hard point and a stress riser since the weld bead is thicker than the tube itself and the weld creates an inconsistency in the tube.

Second, 6-4 sheet is designed to be used as a sheet, not as a tube. If it is formed into a tube, its grain structure can lead to premature tube failure. Indeed, a 6-4 tube will fail through fatigue cycling (repeated flexing) before it should, and independent fatigue tests show that tubing made from 6-4 sheet does not have the fatigue life of a properly drawn 3-2.5 tube.

In recent years, some seamless 6-4 tubing has trickled into the bike industry from outside the U.S. However, it is only being offered as a few internally-butted tube lengths of limited sizes (as determined by tube diameter, wall thickness, and butting placement). These limited offerings are inadequate for modern high-end bike building, which requires a very wide variety of tubing to ensure optimum ride characteristics. In addition, external butting is preferred to internal butting for the reasons outlined in the Tube Butting Processes section of this document, under Manufacturing Overview.

One might argue that the strategic use of the limited 6-4 tube sizes available in combination with 3-2.5 tubes would create a better bike. But there is no weight advantage for bikes currently employing 6-4 tubes over the top-of-the-line 3-2.5 bikes available. And there is no appreciable stiffness or strength benefit either, since 6-4's higher bending stiffness is offset by its lower torsional stiffness, and the butting techniques employed in the 6-4 tubes currently available have a negative impact on fatigue strength. So, 6-4 only adds expense.

[pnoe42]

Toujours pour les anglophones :

TITANIUM ALLOY

Bicycle frames made of Titanium are actually made of a titanium alloy. The two most common titanium alloys used in the cycling industry are 6/4 and 3/2.5. The numerator in each fraction refers to the percentage of aluminum and the denominator refers to the percentage of vanadium in the alloy. These two different alloys are both high strength titanium and are both fairly common in the industry. 3/2.5 titanium alloy is by far the most commonly used for tubing in titanium frames while the 6/4 alloy is actually the stronger of the two.

Many people assume that since 6/4 titanium alloy is stronger, all Titanium frames should use it, but it is not that simple. Because 6/4 is stronger than 3/2.5, the mills who draw titanium tubing have a very difficult time working the 6/4 alloy. In addition, strength of these alloys is not the issue that many people think it is. Quite simply, the high quality 3/2.5 bicycle frames on the market simply do not break. Therefore, making a frame from 6/4 alloy simply doesn't make sense (it just costs more money). Please note that there are 6/4 frames on the market but most of them have seamed 6/4 tubing. The fact that their 6/4 tubing is seamed is very significant. There are three problems with seamed 6-4 titanium. First, in order to make 6-4 plate into tubing it needs to be annealed, lowering the strength by about 20%. Second, the grain structure of the plate, when rolled into the tube shape is altered and no longer appropriate for optimal alloy strength. Indeed, it lowers the tube's strength considerably. Third, the weld area that runs down the length of the tube has a completely different grain structure from the rest of the tube has surface irregularities that lower the fatigue strength of the tube. While these tubes can have well finished external welds, the inside surface of the welds are not finished and the grain structure and surface irregularities present inside the tubes create stress risers that can lead to premature failure.

In addition to the strength of the alloys, the modulus (or measurement of stiffness) is also important. 6/4 and 3/2.5 have effectively the same modulus of elasticity. In simple terms, the two alloys have the same effective stiffness. This in turn means that the ride between frames made out of the two alloys will be the same assuming all other frame specifications are the same.

The Merlin Extralight and Spectrum Super are made out of double butted 3/2.5 custom drawn tubing from Haines International. The tubing specifications Spectrum and Merlin use are the most stringent in the industry (in any industry come to think of it). Even the tubing shipped to Boeing for their passenger jets are not manufactured to as tight tolerances as Merlin/Spectrum's. You can actually see some of the result by looking at the surface finish on a Spectrum or Merlin and comparing it to other manufacturer's frames.

When talking about metals, in this case titanium alloys, there are some basic considerations to be discussed. Tensile strength, yield strength, modulus of elasticity, and notch hardness are all characteristics of metal alloys that effect real world performance.

Tensile strength refers to the greatest longitudinal stress a substance can bear without tearing apart. While this can be a factor in the overall strength of a metal alloy, in a bicycle, it's not the only factor. This is due to the fact that bicycle frames rarely fail by being pulled apart. They fail from either yielding (bending) or from fatigue. Tensile strength alone does not directly quantify how a frame will hold up to these types of failure. In fact, tensile strength (above a certain point) is essentially irrelevant to the strength of a bicycle frame. As long the tensile strength is high enough to resist all TENSILE failures, that is enough.

Like tensile strength, yield strength is also a contributing factor in the overall strength of a frame. Yield strength comes into play as tubing walls gets thinner and tube diameter increases. Thinner tubing tends to buckle or "beer can" more easily. Higher yield strength will help the tubing resist this kind of stress and thus resist "beer can" failure. Because lighter steel and titanium frames do have larger diameter tubing and thinner tubing walls, there can be yield problems especially in head-on crashes. Some tubing is so thin even simple handlebar hits can cause ripples and dents that could lead to failure. Thankfully, larger diameter thin-wall titanium tubing is still much tougher than the ELOS type steel tubing on the market by an average of about 75%. i.e.. it takes about a 75% increase in force to do the same thing to a Spectrum Super than it does to an ELOS type steel frame and you can chalk that strength up to the amazing yield strength of titanium.

Another factor to consider is the modulus (or stiffness) of titanium. Though a fairly technical concept, I'll do my best to explain it. In measuring modulus of a titanium tube, one has to measure it in both bending and torsion to fully evaluate it. Of the two titanium alloys used in bicycle tubing, 6-4 and 3-2.5, the 6-4 is clearly stronger over-all. However, top shelf 3-2.5 and 6-4 tubes compare in some interesting ways.

Although 6-4 sounds great at a glance (and indeed is pretty neat stuff) it is not necessarily better than other titanium alloys in all situations. As expected the stronger 6-4 tubing has a slightly higher modulus in bending compared to the 3-2.5 tubing. However, the 3-2.5 alloy has a higher modulus in torsion. Moreover, if you average the two modulus strengths of the alloys, you end up with a surprisingly even match. Its seems then that to build the most rigid frame with the lowest weight, a builder should use a mixture of both 6-4 and 3-2.5. Of course there is more to it than that though. One must not forget notch hardness.

Now to notch hardness or fatigue strength. Notch hardness refers to a way of quantifying how well the crystal structure of an alloy will hold together under repeated cyclical stresses. This is where 3-2.5 alloy starts to really make sense when compared to the seemingly better 6-4 stuff. Not only does 6-4 have a lower notch hardness than 3-2.5, but the way most 6-4 tubing is manufactured causes additional negative outcomes related to tube strength. The seamless 6-4 titanium tubing on the market is quite well made and finished. It still has the notch hardness problems that all 6-4 has, but its seamless manufacturing eliminates some of problems of seamed 6-4 tubing. Currently, seamless 6-4 tubing is available in very few diameters and gauges, again reducing its usefulness.

Please note that steel tubing, unlike 6-4 titanium tubing, can be rolled and seamed without the same weaknesses. That is because steel tubing can be drawn to smooth the weld, then annealed and heat treated to recover its strength. 6-4 cannot be processed the same way. If you were to heat treat it the way steel is heat-treated, it would make it too brittle for use. If you were to anneal titanium, strength would decrease and for practical purposes, it cannot be cold worked enough to make any significant difference.

If any of that seems to technical, give me a call. I love talking about metal!

In short, I'll say this, 6-4 titanium alloy has no advantage (other than for marketing) over 3-2.5 alloy when it comes to bicycle tubing applications.

En gros le titane 6/4 aurait des avantages en théorie sur le papier (densité/propriétés mécaniques) mais dans la pratique compte tenu de son coût et de sa mise en oeuvre difficile le résultat obtenu ne serait pas bien supérieur voire moins intéressant qu'un bon Ti3-2.5 des familles !

[daddyjulio]

Toujours pour les anglophones :

TITANIUM ALLOY

Bicycle frames made of Titanium are actually made of a titanium alloy. The two most common titanium alloys used in the cycling industry are 6/4 and 3/2.5. The numerator in each fraction refers to the percentage of aluminum and the denominator refers to the percentage of vanadium in the alloy. These two different alloys are both high strength titanium and are both fairly common in the industry. 3/2.5 titanium alloy is by far the most commonly used for tubing in titanium frames while the 6/4 alloy is actually the stronger of the two.

Many people assume that since 6/4 titanium alloy is stronger, all Titanium frames should use it, but it is not that simple. Because 6/4 is stronger than 3/2.5, the mills who draw titanium tubing have a very difficult time working the 6/4 alloy. In addition, strength of these alloys is not the issue that many people think it is. Quite simply, the high quality 3/2.5 bicycle frames on the market simply do not break. Therefore, making a frame from 6/4 alloy simply doesn't make sense (it just costs more money). Please note that there are 6/4 frames on the market but most of them have seamed 6/4 tubing. The fact that their 6/4 tubing is seamed is very significant. There are three problems with seamed 6-4 titanium. First, in order to make 6-4 plate into tubing it needs to be annealed, lowering the strength by about 20%. Second, the grain structure of the plate, when rolled into the tube shape is altered and no longer appropriate for optimal alloy strength. Indeed, it lowers the tube's strength considerably. Third, the weld area that runs down the length of the tube has a completely different grain structure from the rest of the tube has surface irregularities that lower the fatigue strength of the tube. While these tubes can have well finished external welds, the inside surface of the welds are not finished and the grain structure and surface irregularities present inside the tubes create stress risers that can lead to premature failure.

In addition to the strength of the alloys, the modulus (or measurement of stiffness) is also important. 6/4 and 3/2.5 have effectively the same modulus of elasticity. In simple terms, the two alloys have the same effective stiffness. This in turn means that the ride between frames made out of the two alloys will be the same assuming all other frame specifications are the same.

The Merlin Extralight and Spectrum Super are made out of double butted 3/2.5 custom drawn tubing from Haines International. The tubing specifications Spectrum and Merlin use are the most stringent in the industry (in any industry come to think of it). Even the tubing shipped to Boeing for their passenger jets are not manufactured to as tight tolerances as Merlin/Spectrum's. You can actually see some of the result by looking at the surface finish on a Spectrum or Merlin and comparing it to other manufacturer's frames.

When talking about metals, in this case titanium alloys, there are some basic considerations to be discussed. Tensile strength, yield strength, modulus of elasticity, and notch hardness are all characteristics of metal alloys that effect real world performance.

Tensile strength refers to the greatest longitudinal stress a substance can bear without tearing apart. While this can be a factor in the overall strength of a metal alloy, in a bicycle, it's not the only factor. This is due to the fact that bicycle frames rarely fail by being pulled apart. They fail from either yielding (bending) or from fatigue. Tensile strength alone does not directly quantify how a frame will hold up to these types of failure. In fact, tensile strength (above a certain point) is essentially irrelevant to the strength of a bicycle frame. As long the tensile strength is high enough to resist all TENSILE failures, that is enough.

Like tensile strength, yield strength is also a contributing factor in the overall strength of a frame. Yield strength comes into play as tubing walls gets thinner and tube diameter increases. Thinner tubing tends to buckle or "beer can" more easily. Higher yield strength will help the tubing resist this kind of stress and thus resist "beer can" failure. Because lighter steel and titanium frames do have larger diameter tubing and thinner tubing walls, there can be yield problems especially in head-on crashes. Some tubing is so thin even simple handlebar hits can cause ripples and dents that could lead to failure. Thankfully, larger diameter thin-wall titanium tubing is still much tougher than the ELOS type steel tubing on the market by an average of about 75%. i.e.. it takes about a 75% increase in force to do the same thing to a Spectrum Super than it does to an ELOS type steel frame and you can chalk that strength up to the amazing yield strength of titanium.

Another factor to consider is the modulus (or stiffness) of titanium. Though a fairly technical concept, I'll do my best to explain it. In measuring modulus of a titanium tube, one has to measure it in both bending and torsion to fully evaluate it. Of the two titanium alloys used in bicycle tubing, 6-4 and 3-2.5, the 6-4 is clearly stronger over-all. However, top shelf 3-2.5 and 6-4 tubes compare in some interesting ways.

Although 6-4 sounds great at a glance (and indeed is pretty neat stuff) it is not necessarily better than other titanium alloys in all situations. As expected the stronger 6-4 tubing has a slightly higher modulus in bending compared to the 3-2.5 tubing. However, the 3-2.5 alloy has a higher modulus in torsion. Moreover, if you average the two modulus strengths of the alloys, you end up with a surprisingly even match. Its seems then that to build the most rigid frame with the lowest weight, a builder should use a mixture of both 6-4 and 3-2.5. Of course there is more to it than that though. One must not forget notch hardness.

Now to notch hardness or fatigue strength. Notch hardness refers to a way of quantifying how well the crystal structure of an alloy will hold together under repeated cyclical stresses. This is where 3-2.5 alloy starts to really make sense when compared to the seemingly better 6-4 stuff. Not only does 6-4 have a lower notch hardness than 3-2.5, but the way most 6-4 tubing is manufactured causes additional negative outcomes related to tube strength. The seamless 6-4 titanium tubing on the market is quite well made and finished. It still has the notch hardness problems that all 6-4 has, but its seamless manufacturing eliminates some of problems of seamed 6-4 tubing. Currently, seamless 6-4 tubing is available in very few diameters and gauges, again reducing its usefulness.

Please note that steel tubing, unlike 6-4 titanium tubing, can be rolled and seamed without the same weaknesses. That is because steel tubing can be drawn to smooth the weld, then annealed and heat treated to recover its strength. 6-4 cannot be processed the same way. If you were to heat treat it the way steel is heat-treated, it would make it too brittle for use. If you were to anneal titanium, strength would decrease and for practical purposes, it cannot be cold worked enough to make any significant difference.

If any of that seems to technical, give me a call. I love talking about metal!

In short, I'll say this, 6-4 titanium alloy has no advantage (other than for marketing) over 3-2.5 alloy when it comes to bicycle tubing applications.

En gros le titane 6/4 aurait des avantages en théorie sur le papier (densité/propriétés mécaniques) mais dans la pratique compte tenu de son coût et de sa mise en oeuvre difficile le résultat obtenu ne serait pas bien supérieur voire moins intéressant qu'un bon Ti3-2.5 des familles !

merci pour le résumé car mon anglais est médiocre et lointain.

[rickyfirst]

J'avais déjà lu ce bourrage de mou qui essaye de justifier que Seven n'utilise pas de 6/4 pour ses tubes.

La lecture de cet argumentaire conduit tous de même à comprendre que la mise en oeuvre du titane 6/4 nécessite des précautions opératoires que Seven ne veut ou ne peut prendre.

Bref le 6/4 c'est plus technique et Seven préfère jouer la sécurité en ayant recours à des certificats aérospatiaux (ce qui fait toujours 'sérieux').

Ce choix est dommage car le travail en feuille permet de travailler le comportement du tube en lui donnant des formes spécifiques.

[mecacote]

J'avais déjà lu ce bourrage de mou qui essaye de justifier que Seven n'utilise pas de 6/4 pour ses tubes.

La lecture de cet argumentaire conduit tous de même à comprendre que la mise en oeuvre du titane 6/4 nécessite des précautions opératoires que Seven ne veut ou ne peut prendre.

Bref le 6/4 c'est plus technique et Seven préfère jouer la sécurité en ayant recours à des certificats aérospatiaux (ce qui fait toujours 'sérieux').

Ce choix est dommage car le travail en feuille permet de travailler le comportement du tube en lui donnant des formes spécifiques.

6.4 en feuille formée soudée presente des interet , comme tu le dis RICKy , reste le cout ?

[rickyfirst]

J'avais déjà lu ce bourrage de mou qui essaye de justifier que Seven n'utilise pas de 6/4 pour ses tubes.

La lecture de cet argumentaire conduit tous de même à comprendre que la mise en oeuvre du titane 6/4 nécessite des précautions opératoires que Seven ne veut ou ne peut prendre.

Bref le 6/4 c'est plus technique et Seven préfère jouer la sécurité en ayant recours à des certificats aérospatiaux (ce qui fait toujours 'sérieux').

Ce choix est dommage car le travail en feuille permet de travailler le comportement du tube en lui donnant des formes spécifiques.

6.4 en feuille formée soudée presente des interet , comme tu le dis RICKy , reste le cout ?

Comme le dit Seven, c'est technique de plier et souder des feuilles de titane 6/4. Cette technicité a un coût.

Seven juge que cela ne vaut pas la peine, c'est pour le moins excessif.

[Etienne]

J'avais déjà lu ce bourrage de mou qui essaye de justifier que Seven n'utilise pas de 6/4 pour ses tubes.

La lecture de cet argumentaire conduit tous de même à comprendre que la mise en oeuvre du titane 6/4 nécessite des précautions opératoires que Seven ne veut ou ne peut prendre.

Bref le 6/4 c'est plus technique et Seven préfère jouer la sécurité en ayant recours à des certificats aérospatiaux (ce qui fait toujours 'sérieux').

Ce choix est dommage car le travail en feuille permet de travailler le comportement du tube en lui donnant des formes spécifiques.

6.4 en feuille formée soudée presente des interet , comme tu le dis RICKy , reste le cout ?

Comme le dit Seven, c'est technique de plier et souder des feuilles de titane 6/4. Cette technicité a un coût.

Seven juge que cela ne vaut pas la peine, c'est pour le moins excessif.

En dehors du fait que nul ne nous oblige à le partager, je suis surpris que tu considères l'avis de Seven comme du bourrage de mou

Je suis assez d'accord pour penser qu'ils justifient ainsi leur non-utilisation du 6/4 mais je ne vois pas ce qui ferai penser que c'est pour justifier une lacune ou un mauvais choix, ils peuvent très bien avoir cet avis en tant qu'experts du titane, ce qu'ils ne sont pas moins que Litespeed si je ne m'abuse

En se plaçant sur des créneaux différents, ils ont des arguments différents ... pas de problème, mais pas de jugements à l'emporte-pièce, même si tu roules sur un Litespeed, qui est au demeurant et de mon point de vue, l'un des plus beaux vélos de ce forum

[rickyfirst]

Comprenont nous bien, je ne "défends' pas les choix de Litespeed par rapport aux choix de Seven. Je critique l'argumentaire de Seven qui essaye de discréditer le titane 6/4 en disant que le 6/4 n'est pas intéressant car difficile à travailler.

Seven devrait se contenter de dire pourquoi il juge suffisant les tubes ronds en titane 3/2,5 plutôt que d'essayer de dire que le 6/4 n'est pas utile pour faire des tuibes.

Il est d'ailleurs à noter que Litespeed a des déboires avec les feuilles de 6/4 et que ce n'est pas la méthode la plus simple pour faire un cadre en titane.

[duduche]

Seven devrait se contenter de dire pourquoi il juge suffisant les tubes ronds en titane 3/2,5 plutôt que d'essayer de dire que le 6/4 n'est pas utile pour faire des tuibes.

Pourquoi ne serait-ce pas possible d'expliquer les 2 argumentaires en parallèle ?

Sinon ça serait intéressant d'avoir l'avis de jplv qui a fabriqué des cadres en 6/4 mais sans utiliser la technique des feuilles...

[MIMI 25]

Il me semble que Passoni utilise toujours des feuilles sur leur haut de gamme
A+

[mecacote]

Il me semble que Passoni utilise toujours des feuilles sur leur haut de gamme
A+

Il me semble que Passoni fait plus de carbone titane car on ne voit presque plus de titane Passoni mais il fait aussi Rewell ..en tubes ronds

VB

[MIMI 25]

Tu parles,à plus de 5000 euros le cadre titane,cela ne court pas les rues.
Il me semble qu'ils utilisaient du grade 11 en feuilles pour le top évolution
A+
Et à épaisseur différenciée d'où l'utilisations de feuilles,me semble-t-il

[Erikerac]

Désolé mais pour moi ça ne sera pas un JPLV......

[levacon]

Désolé mais pour moi ça ne sera pas un JPLV......

tout le monde a le choix et sa préférence !

JPLV