Horst-Link Pivot Placement and Pedaling Efficiency (Norco ART) by PHeller

In case anyone cares, I've been playing around in Linkage V3 and experimenting on various newer designs. I wanted to determine what specific in the suspension design(s) is affecting anti-squat or if its always a sum of multiple factors. What I've determined from moving the linkage points of nearly 12 different models and 5-6 different suspension styles is that the placement of the main pivot has a drastic influence on pedaling efficiency (all shocks being equal). It appears as though the relationship between the main pivot and real axle plays a major part in pedaling efficiency.

One thing to keep in mind about this comparison is that I'm not looking at any other dynamic of suspension kinematics. Suspension design is all about compromise, and moving any of the pivots can have a negative or positive affect on ride quality.

Actual position of all pivots on a 2013 Range Killer-B. This bike is a great example of a good pedaling, highly efficient Horst-Link suspension design. In this comparison I will leave the gearing in "climbing mode" with a 32 front ring and a 36 rear cog. Notice the placement of the main pivot, right below the 32t rings outer edge.

Here we can see the drastic improvement in anti-squat percentage just by moving the main pivot 10 or 20mm.

Here we can see the drastic improvement in anti-squat percentage just by moving the main pivot up 10 or 20mm. If I were to lower it by the same amount, the anti-squat percentage would drop.

Lowering the chainstay pivot has a minor affect on anti-squat and would likely interfere with derailure or chain.

Lowering Seatstay/Rocker Pivot has drastic affect on anti-squat, but this is likely an unrealistic location. Binding, weird leverage curves, and numerous other problems could result from this placement.

High seatstay/rocker pivot lowers anti-squat. This may provide benefits to leverage curve and other dynamics. I am only interested in the anti-squat changes.

In my next installment, I will look at how pivot placement on the Specialized Enduro affects the anti-squat properties of that design.

Author Info:

PHeller

Member since Dec 16, 2007
15 articles

3 Comments

Nimble9 (Oct 3, 2014 at 17:06)

This is cool! I'd love to see an enduro pedaling efficiency compare o haha

PHeller (Oct 4, 2014 at 6:35)

I did another blog post that looked at the Enduro's design and the effects of changing its pivot locations, but if you want to see how well other bikes ride in comparison to these, a good blog is Tony's linkagedesign.blogspot.com he uses the same program I used but has tables that record the anti-squat percentage at various gear combinations.

Nimble9 (Oct 4, 2014 at 7:30)

Nice!!!!