That is a great question, the axle path was/is the secret to the Quad Link 2.0's success. Have a look at this link
http://www.singletrackworld.com/2011/08/marin-2012-quad-link-3-bouncy-29ers-and-more/judging by the geometry of the links as they are in the photos, it seems it would be hard to get the wheel to move in a rearward direction at all, let alone for the first 1/3rd of the travel.
If we do a 2012 Marin test, I'll be sure to include axle path comparison (if available)
the lower link looks to be set so it would rise and extend rearwards in the early travel to continue the current pattern.
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