En esta entrada voy a analizar a la Marin Attack Trail, un modelo con 150-160mm de recorrido y ruedas de 650B en el que Marin mantiene su sistema de Pivote Virtual. El cambio del Quad-Link 2.0 al 3.0 hace un par de años fue un paso atras en originalidad y diseño, pero el funcionamiento este sistema sigue siendo bastante especial...
Como podéis ver en las primeras gráficas el sistema Quad Link tiene una Eficacia de Pedaleo muy buena. Si lo montamos con un XX1 el funcionamiento es impecable, con un porcentaje de Anti-squat en torno al 100% y si lo montamos con un 3x10 o un 2x10 el funcionamiento también es muy bueno. El Pedal-kickback (12º) y el Brake-squat (70%) están en un termino medio.
En la gráfcia del Leverage Ratio vemos como el sistema tiene una progresividad brutal (3.55-2.25), se puede decir que es incluso un poco excesiva, pero esto también tiene sus ventajas: te permite utilizar un amortiguador HV sin reducir volumen, utilizar un Tune Low en el Hidráulico, ya que el sistema pedalea muy bien, puedes subir el Sag al 30%-35%-40% sin ningun problema, etc... El cuadro viene equipado con una horquilla de 160mm, pero con este LR está claro que la trasera no va a quedar descompensada.
En la gráfcia del Leverage Ratio vemos como el sistema tiene una progresividad brutal (3.55-2.25), se puede decir que es incluso un poco excesiva, pero esto también tiene sus ventajas: te permite utilizar un amortiguador HV sin reducir volumen, utilizar un Tune Low en el Hidráulico, ya que el sistema pedalea muy bien, puedes subir el Sag al 30%-35%-40% sin ningun problema, etc... El cuadro viene equipado con una horquilla de 160mm, pero con este LR está claro que la trasera no va a quedar descompensada.
Un saludo.
6 comentarios:
I see this is one interesting suspension design...would like to read what Antonio and Chris think about it :)
ciao
Alberto
I would have liked to have seen QuadLink 2 further developed but you are right, Alberto, QuadLink 3 has its good points.
My normal approach in weighing up a suspension implementation is to compare / contrast it with the range of designs that seek to satisty a similar need i.e. whatever the differences between them they share a paradigm or problematic that makes some issues prominent and important and others secondary etc. Then you simply judge which one(s) meets the design objectives better.
The Attack Trail (and the QuadLink 3 linkage) is most usefully compared with the Mondraker Dune - it is not a coincidence that this appears for comparison purposes in Antonio's graphs. Both aim to provide plenty of anti-squat around SAG but rely on a dynamic geometry that favours pedal kickback reduction further into the bike's travel. So, which is better? Allowing that there is a lot of room for subjectivity in such judgements I think the Mondraker is better - the LR has a more sensible escalation. There is not a lot in it though. When you consider Mondraker's geometry innovations however I think the Dune is the better overall package.
While the Dune may be the most obvious comparison bike for the Attack Trail there are others. Keeping implementation differences to one side, recent models like the BMC Trailfox and Canyon Spectral can be considered as rivals that occupy the same design space. The Ibis Mojo too, uses a low kickback suspension implementation (despite its use of a minted DW-link). Is the Attack Trail and its QL3 linkage better than these? Well, it may not be better but it gains a lot by the association with such good company.
Un saludo
Chris
Thanks Chris for the well argumented answer.
I believe, too, Mondraker hit an homerun with the new Dune, being so forward with the geometry :) and the suspension design, this year.
I'm deciding between this Dune and the Norco Range Carbon for my next enduro frame, could you spend two words giving your advices in regard?
Thanks in advance
Alberto
Hola Alberto,
I like both bikes so I am not sure that I can help you make this decision. Still, I will try to give a meaningful response to your question. As Antonio’s site is not normally about advice though (I have been known to bend that rule but feel a bit out of order when I do) please go to the URL below for my response.
https://docs.google.com/document/d/1DBBnwqGz6wquVMDYkgZ6RJdpfnD8qkOjpwL97MdTZzk/edit?usp=sharing
Un saludo
Chris
So many interesting observation in your written, Chris, first of all many thanks for eviscerating so deeply pros and cons of this hard choice. Don't you agree, if you read again your doc, there is a clear winner? :-) Lastly, the thing I didn't mention as a disclaimer is I will use a 30t XX1 configuration...
Ciao
Alberto
It is a genuine surprise to me that my words favour the Dune. It is the perspective of others on this site who have caused me to reconsider my inclination to see anti-squat as the main story and pedal feedback just a sideshow.
But there is still a purist strain in the way I look at these things. I think a better balance can yet be struck in this inevitable suspension geometry trade off between pedaling platform and pedal feedback.
In this connection I would point to those unconventional designs that prefigure a possible future for mountain biking - the Zerode and i-Track designs. Also, commercial reality will probably liven things up at bit in the short term. There are major companies selling full suspension MTBs that fall well below the level of their smaller competitors in design terms. Why buy Specialized when you can get a Mondraker? Marketing won't cut it forever. Specialized, in particular, needs to do something to make itself look relevant once again, and soon.
Un saludo
Chris
Publicar un comentario