This is a question for Derby, DW, or anyone else with both DW Link and general suspension expertise.
I have read many of Derby's and DW's comments on the superiority of the DW Link but remain confused.
In viewing the animation of the 2005 MKIII using Linkage v2.5, it would appear that the largely rearward axle path of this bike results in pedal kickback of up to 21 degrees in the 36/16 gear combo. The kickback declines to a maximum of 16 degrees in the 44/11 combo, but rises to a whopping 36 degrees in the 22/16 combo. These figures assume that only the rear wheel is moving. When you factor in the movement of the front suspension, which results in a forward pivoting of the bottom bracket, the overall feedback rises even higher. I fail to understand how the DW Link can be justified as superior when many other suspension designs demonstrate far less feedback. Are we dealing with a tradeoff here between bob and feedback? If so, this would represent simply a different type of good design to me, not a design that's superior to everything else.
Furthermore, my understanding is that the DW Link reduces bob by using the chain tension created by pedaling to push the rear wheel in a direction (rearward) opposite the direction that results in compression of the suspension--at least, the DW Link does this during the first part of the rear axis's travel. This process, almost by definition, would indeed seem to reduce the compression of the suspension that we know as "bob." However, while the rider can observe his spring and smile at the lack of movement, is he really saving his body's energy? It would seem to me that the rider is wasting energy on driving the rear wheel backwards--and perhaps even excessively downwards on hardpacked terrain--instead of driving the whole bike forwards as much as possible. In other words, the lack of bob may be true, but at least some of the gain in efficiency may be an illustion. A bike that keeps the wheel vertical during initial travel and that has a pivot placed in a manner so as to reduce the opportunity for the rider to lift the rear merely by pedaling would seem like it would offer superior efficiency.
Derby, if you respond, it would be interesting to know your affiliations, if any, as well. Are you a champion of the DW Link simply based on your analyses, or are you affiliated with Ibis or Iron Horse in any way?
I have read many of Derby's and DW's comments on the superiority of the DW Link but remain confused.
In viewing the animation of the 2005 MKIII using Linkage v2.5, it would appear that the largely rearward axle path of this bike results in pedal kickback of up to 21 degrees in the 36/16 gear combo. The kickback declines to a maximum of 16 degrees in the 44/11 combo, but rises to a whopping 36 degrees in the 22/16 combo. These figures assume that only the rear wheel is moving. When you factor in the movement of the front suspension, which results in a forward pivoting of the bottom bracket, the overall feedback rises even higher. I fail to understand how the DW Link can be justified as superior when many other suspension designs demonstrate far less feedback. Are we dealing with a tradeoff here between bob and feedback? If so, this would represent simply a different type of good design to me, not a design that's superior to everything else.
Furthermore, my understanding is that the DW Link reduces bob by using the chain tension created by pedaling to push the rear wheel in a direction (rearward) opposite the direction that results in compression of the suspension--at least, the DW Link does this during the first part of the rear axis's travel. This process, almost by definition, would indeed seem to reduce the compression of the suspension that we know as "bob." However, while the rider can observe his spring and smile at the lack of movement, is he really saving his body's energy? It would seem to me that the rider is wasting energy on driving the rear wheel backwards--and perhaps even excessively downwards on hardpacked terrain--instead of driving the whole bike forwards as much as possible. In other words, the lack of bob may be true, but at least some of the gain in efficiency may be an illustion. A bike that keeps the wheel vertical during initial travel and that has a pivot placed in a manner so as to reduce the opportunity for the rider to lift the rear merely by pedaling would seem like it would offer superior efficiency.
Derby, if you respond, it would be interesting to know your affiliations, if any, as well. Are you a champion of the DW Link simply based on your analyses, or are you affiliated with Ibis or Iron Horse in any way?