Ich les ja immer parallel bei PB mit und da haben sich nun paar Schwergewichte geäußert:
naild-it (23 hours ago)
i was lucky enough to be part of the press-camp ...
think about it this way: antisquat/progressivity/leverage ratio graphs... these are all static and for-the-most-part two dimensional ...
the key to the design is the ability to balance both the rider's pedal input (graphs above) AND the inertia (acceleration or deceleration) of the rider ... yes it is dynamic and not easy to describe on paper or the web
the current tools of curves and ratios are insufficient to fully describe the design.
--> Daraufhin gabs erstmal Schelte von vielen usern. Aber jemand, der nun wirklich richtig Ahnung hat, hat wie immer ein sehr diplomatisches und technisch detailliertes Statement abgegeben:
VorsprungSuspension (11 hours ago)
@ctd07: every time you lock up the rear wheel (which happens quite frequently because every time the wheel leaves the ground under any substantial braking, there's nothing stopping it from slowing down anymore), it no longer matters whether you're pedaling - chain growth can still pull on the pedals because the freewheel is not unloading chain slack any more.
While I'll reserve comment on real world performance until I actually ride or measure one of these up,
@naild-it does actually have a valid point about anti-squat curves: the standard 2D anti-squat curves assume the rider isn't moving up and down on the bike whilst pedaling, and that the bike is on flat ground, and that the rear wheel is moving up and down rather than the sprung mass shifting relative to the ground, and that you're in one particular gear. In practice, even in a single gear there would need to be at least a 5-dimensional curve to simultaneously display all of the relevant factors so as to see a true net force in any situation. This is pretty hard to display graphically given that we only have 3 physical dimensions and your computer monitor is 2D. Weagle has made many references to this in the past and dw-link designs don't run at "exactly" 100% anti-squat at the sag point for that reason. Quotation marks because it's never exact anyway.
Note that this does not in any way mean I am somehow defending or complimenting this particular design - skepticism is never unwarranted really - just discussing these particular comments. I will say however that for any 1DOF axle path, there is nothing new here in terms of the physics involved. Using a sliding element instead of a rotating element does not necessarily generate a centre of curvature that is substantially or inherently different or superior. Migration of the CC (as opposed to the IC) coupled with gearing (chainline) and wheelbase are the invariants with regards to pedaling performance, irrespective of the specific IC location or migration. As a result, 2D anti-squat curves are imperfect (ie 100% anti-squat does not actually mean zero bob) but not irrelevant, as relatively small "fudge factors" can be applied to make them about as accurate as they realistically can be given the variable biomechanics of the rider.
Ein vollgefedertes Mountainbike, das berghoch mit sportlichen Trailbikes mithalten kann und bergab wie ein echtes Enduro kaum Grenzen kennt: In Zeiten der Spezialisierung klingt das wie ein kaum zu erfüllender Wunschtraum. Polygon behauptet nun, mit dem Square One EX genau so ein Bike im Köcher zu haben und setzt auf die neue Sliding Four Bar-Kinematik. Was hat es damit auf sich?
