Yeti SB-95 29'' 2012

En esta entrada voy a analizar la nueva Yeti SB-95, la primera doble de 29'' de la marca, con 120mm de recorrido y el nuevo sistema de suspensión Switch. También voy a aprovechar para dar mi opinión sobre la demanda que Santa Cruz le ha puesto a Yeti y a Sotto Group.







Como podéis ver en los primeros gráficos la eficacia de pedaleo de la SB-95 es muy buena, con un porcentaje de Anti-Squat del 100-120% en los desarrollos mas importantes por lo que va a funcionar muy bien con una transmisión 3x10 o 2x10 y con ciclistas que sean muy altos. Si repasáis la entrada en la que hablaba de la SB-66 veréis como los porcentajes de la SB-95 son un poco mas altos y no se si esto se debe a que es un modelo de 29'' o a que es un modelo pensado para un uso mas XC... cuando aparezca la SB-65 saldremos de dudas. Si os fijais muy bien en las fotos de los dos cuadros os daréis cuenta de que la posición de la excéntrica varía de uno a otro, en la SB-95 está un poco mas alta y mas adelantada. El resto de parametros son bastante previsibles: La gráfica del Anti-Squat es muy plana por lo que el Pedal Kickback (13.5º) también es elevado. El Brake Squat (84%) está un valor medio-alto.

En la gráfica del Leverage Ratio vemos como el sistema es muy lineal, aunque en esta ocasión el cuadro tiene un caracter mas rutero que el de la SB-66, por que se puede decir que es un comportamiento mas o menos aceptable. En la comparativa he incluido a la Ibis Ripley, con un funcionamiento muy similar y a la Intense Spider, un VPP "de manual" que como veis no se parece en nada a la Yeti.
_______________________________________________________

Paso ahora a hablar del tema de la demanda...

En mi opinión existen dos tipos de patentes: Hay patentes muy precisas, que definen claramente al objeto que se está patentando y hay patentes muy difusas, en las que se patenta un concepto con una enorme catidad de variaciones posibles. La patente del DW-Link por ejemplo es de este tipo, es bastante amplia, protege todos los diseños de Dave Weagle y crea una "Zona de Seguridad" alrededor de estos diseños. En los últimos años ninguna marca ha intentado copiar el comportamiento exacto del DW-Link, pero si ha habido varios casos en los que se ha entrado un poco en la "Zona de Seguridad". En muchos de estos casos el comportamiento es completamente distinto al DW-Link, y la verdad es que no existe intención de plagio, el problema es que la zona de seguridad de esa patente es tan amplia que a veces los diseños de otras marcas la pisan un poco.

La patente del VPP sin embargo es del primer tipo, es muy precisa, y esto supone un gran problema porque hay muchos modelos de Santa Cruz y de Intense que se salen de su propia patente, no existe una "Zona de Seguridad". Antes de que apareciese la patente del VPP ya existian modelos de Pivote Virtual en los que los dos links giraban en sentidos opuestos (Nicolai Helius, y similares...), y por eso Santa Cruz (Outland) no pudo patentar el concepto de los dos links girando en direcciones opuestas, pero ninguno de estos sistemas tenía una trayectoria de la rueda en forma de "S" y eso si se pudo patentar. Yo no soy un experto en patentes, pero para mi el VPP es un sistema que cumple dos requisitos: Links girando en sentido opuesto y trayectoria en forma de "S".

Ahora es cuando mas de uno se va a llevar una sorpresa... En la actualidad ningun modelo de Santa Cruz tiene una trayectoria con forma de "S". Las primeras Blur, Blur LT y VP-Free si tenían este tipo de trayectoria, pero los modelos han ido evolucionando y ya no la tienen. Intense tenía este tipo de trayectoria en los modelos de XC-AM de primera generación y lo sigue manteniendo en los de segunda generación, pero los modelos de DH creo que nunca tuvieron una trayectoria en forma de "S".

Como podéis ver la patente del VPP se ha quedado un poco corta, a Santa Cruz seguramente le encantaría que su patente no fuese tan especifica, pero la realidad es la que es, y por eso los únicos recursos que les queda son: El marketing, para hacer creer a la gente que tienen patentado todas las variantes en las que dos links giran en sentido opuesto (La trayectoria ya no importa...) y Las demandas hacia cualquier marca que intente algo parecido. Y es que en USA, aunque pierdas la demanda, el acusado puede acabar arruinado por culpa de los abogados...

En Europa hay varias marcas que utilizan un sistema de Pivote Virtual con links girando en sentido opuesto: Antidote, Decathlon, Lapierre, Propain, Rock Machine, Silverback, Voitl, Witchbroom... y en la mitad de los casos la trayectoria no tiene forma de "S" por lo que no debería haber problemas de patentes. Los únicos casos que conozco en los que creo que se infringe la patente del VPP son el de Decathlon, Silverback, Voitl y Lapierre.



En este gráfico expongo mas o menos como veo yo la situación actual..........
El Sistema Switch de Yeti está bastante alejado de la patente del VPP, la Trayectoria no tiene forma de "S" y los Links ni siquiera giran en sentido contrario, sino que cambian de dirección a mitad de camino. Yo creo que Santa Cruz tiene motivos para demandar por ejemplo a Decathlon, y Decathlon creo que tiene motivos para demandar a Yeti, lo que no tiene ningun sentido es que Santa Cruz demande a Yeti.

Un saludo.

13 comentarios:

Josep Barberà dijo...

Madre mia Antonio, tendré que tomar asiento, tomarme un reconstituyente i releer un par de veces mas... el tema de las patentes!.

Un saludo.

Anónimo dijo...

hola antonio, soy cachopo man...
como siempre andas ávido de nuevas marcas, he encontrado esto:
http://www.nsmb.com/4929-bilt-bikes-coming-to-life
no se si las conoces.

Por cierto, para cuando un tutorial de sistemas de suspensión? Hay varios monopivotes con bieleta que yo creía fsrs o fourbars... torpe que es uno ;)
Un saludo

Antonio Osuna dijo...

Si, esa marca la vi hace un par de dias y tiene buena pinta.

Y lo del tutorial pues no le veo mucho sentido, para que quieres clasificar a los cuadros por sistemas si luego lo que importa es el funcionamiento... Incluso dentro de una misma marca hay cuadros que no se parecen en nada entre si, y usan el mismo sistema...

Un saludo.

Chris dijo...

An invention ought to be patentable as long as it is unique, non-obvious, not already in use in a patented or non-patented (public domain) form and as long as the patent only applies to particular forms/implementations of the invention that are sold by the patent holder. Patents moreover should only apply to "inventions", i.e. some kind of apparatus, not to the body of scientific knowledge that informs or underlies the invention. Using this simple or simplistic starting point I conclude that patents are largely out of control.

I would say that that the claim of patent infringement against Yeti and Sotto Group by Santa Cruz is unfortunate not because the Yeti SB bikes don't touch on the Santa Cruz VPP patents but because Yeti's produced versions of a VPP-like bike have a contrasting implementation that should be considered to be sufficiently different so as not to activate (valid) patent protection measures.

Still, I have no sympathy for Yeti or the Sotto Group in their independent claims to ownership of any patentable inventions in their "Switch Technology". First, the Yeti bikes have an unmistakable mechanical resemblance to the Decathlon/BTwin bikes that have been around for ages. Sotto/Yeti's attempted re-patenting of the Decathlon invention in a different jurisdiction is somewhat concerning. Second, the "switch" in "Switch Technology" is arguably an obvious feature that should not be protected because its effect would be to radically restrict innovation in pivot placement of closely set linkages. Dave Weagle's new Ibis Ripley DW-link, for example, uses a "switch" that has nothing to do with the Yeti/Sotto design but could still attract the attentions of an aggressive patent infringement lawyer. Such a situation would be absurd. It is also important to remember that Corsair have been using a linkage (on the Konig bike) that relies on a switch, in some ways similar to what we see on the Yeti bikes, for years.

Whatever their intentions, which may be no more than to protect themselves from the possibility of litigation, the Sotto Group appear be obsessive about acquiring patents. Just have a look at their website. They seem to want a piece of just about every area of active research on (rear wheel) bicycle suspension design and implementation. But the patents that they have been granted (in the US) are full of general verbiage and very little real specification of what would constitute an invention. Very worrying.

It would be far better for riders and most bicycle manufacturers if patents were very deliberately limited in their form and scope unlike the current situation.

Un Saludo

Dakhil dijo...

Hey Antonio,

Just wanted to let you know that the actual travel of the SB-95 is 127mm, not 120mm. This will change the average LR, as well as the graph that you've come up with. Just a heads up! Thanks again for all that you do!

And by the way, what are your thoughts on the SB-95 having such a constant, linear LR curve? At 25 to 30% sag, it is about the same as the Turner Sultan, and even close to the Mojo HD's 2.6:1 at sag, as examples. I'm wondering, however, if small bump compliance is a factor of the LR from 0mm to sag or so, or if we should be paying more attention to what the LR is at sag, as we compare different bikes and attempt to assess how small bump compliance will be. Any thoughts, insight, etc?

Antonio Osuna dijo...

Hello Dakhil,

As I said in the 5-Spot comment, sometimes I trust a lot my models, and sometimes I rush them a little bit. At this time of the year I receive a lot of emails asking me to review the new models as soon as possible.... When I reviewed this model the pictures weren't 100% perfect and maybe the model is not as good as the others, I can accept 3-4 mm of difference but 7 mm is probably too much and I should check it out again. It's a difficult model too, with all the pivot very close, etc...

Anyway, the LR is going to be very linear, that's something that is not going to change and it's probably the only flaw of the bike.

For a 26er with 5 inches of travel a linear Graph is not bad, but 26ers and 29ers are completely different... Everyone understand that you can not abuse a 26er with 5', it's just a trailbike, almost an XC bike.

A 29er is "completely different", or at least that's what some companies are trying to say. If you mount a 140mm fork on the frame and write a few reviews describing the bike almost as a DH Bike then the LR is too linear. So it's not a frame problem, is just a marketing problem.

That's why I don't like 120mm 29ers, 100mm is nice for XC, 140mm is nice for trailbikes. Companies that build 120mm bikes try to keep everyone happy with just one model, but that's impossible.

Best Regards,
Tony.

Dakhil dijo...

Excellent response.

You have me somewhat questioning the Turner Sultan now, which sits at 125mm of rear travel, but it is my current fav. I'm pretty much deciding between the Sultan, 5 Spot and SB-95. I really, really wish the SB-95 had been designed with a progressive LR. Talk about perfect! That cockpit feels so comfy, but the ride is a bit harsh for my tastes, seeing as I'm not racing.

This pushes me more towards the Sultan, especially since the SB's force capacity is much lower than the Sultan, and the Sultan's got the flexibility to take a coil shock, should one want to try that out. I'm 220 pounds, so a coil shock experiment is inevitable. : D

If I didn't feel so much more comfy on 29ers, I'd probably be leaning 5 Spot. Well, that, and the fact that the LR of the Spot is over 2.8:1. At 220 pounds, I'm a bit wary of this, though running coil would likely take care of that issue (I could definitely be wrong here). Decisions, decisions....

Antonio Osuna dijo...

I think the Sultan is very nice, it has 5'' of travel but the system and the geometry are very aggressive, so it match very well how the bike is marketed. I think that's important, telling the customers what a bike can really do.

So if you are going to buy something yet, that's one of the best options and at your weight a coil is a good idea, if not you can send the air shock to push...

Best regards,
Tony.

Dakhil dijo...

Indeed. I really do feel that the Sultan is the best all-arounder for my weight, riding style, comfy geometry, durability, flexibility, etc. The only gripe, naturally, is the price, but I suppose when you're ticking box after box of what you're looking for in a bike, you'd be asking a lot for such a rig to also be cheap.

What are your thoughts on high LR and heavier riders? I know it's considered a bad idea by most; I'm just wondering if a coil shock helps with that at all, or if it's more about the durability of the frame, more so than the feel of the suspension. That's what I've gathered so far from my discussions with Varaxis. High LR + heavy rider = recipe for frame issues.

I think I'm asking more due to just noticing the El Guapo 29 (prototype, of course), than because of my attraction to the % Spot. The El Guapo 29 has my attention! The LR is much higher than the Sultan's, but less than the Spot.

Antonio Osuna dijo...

I think a coil shock is always going to feel better, no matter if you are light or heavy. An air shock can feel nice too but if the bike has a High LR you can actually reach the maximum pressure allowed by the manufacturer of the shock and you are going to need a custom tune. You can also have some frame issues, but mainly with first year models, The Sultan has suffered a few iterations so it's not going to be a problem.

Anyway, you are really not that heavy, but I think the idea of using a coil on the Sultan is very nice, it's a way to compensate the lack of travel. Sultan + Coil + 140mm fork = Nice bike.

Best Regards,
Tony.

Dakhil dijo...

Thanks for the reply Tony.

I think I've settled on Sultan, El Guapo 29 or Prime, for this first go-round of bike selection. In the meantime, I'm gonna grab the SB-95 to have that kit, and a bike to ride while I continue to make my decision (including test rides/demos when/if possible). If I'm able to get a good price on a Sultan with all the component swaps/upgrades I'm looking for, I may grab it straight away. If not (unlikely, due to the stock wheel set being so terrible and a costly upgrade), I'll continue as planned.

95% chance I grab the Yeti this coming week, and start enjoying these Washington state trails! Thanks again.

Skidad dijo...

So how does the new Banshee KS Link fit into the VPP patent scheme of things? At least I believe Banshee classifies it as VPP. Short links that move in the same direction looks more DW Link or Quad Link 2 to me than VPP but I'm no suspension expert. From Antonio's charts and graphs it's performance is also quite similar to that of DW Link or Giant Maestro and very different from the VPP of SC or Intense and dare I say much better as well in performance overall.

Thank you,
Jeff from the USA

Antonio Osuna dijo...

Well, there is a big group of Virtual Pivots that doesn't fit inside the Santa Cruz VPP or DW-Link: Banshee, BMC, Canfield, Giant, Jeronimo, Karpiel, Marin, MDE, Mondraker, Whyte, Zumbi...

All these Systems have a very steep Anti-squat curve and they work in a similar way. The DW-Link has a flattish curve, so it's different, even if it has two links rotating in the same direction, and VPP It's completely different, it's curve goes up and down.

Best Regards,
Tony.

 

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