Yeti/Commencal Six-Bar Comparison

I’m putting together a quick write-up to explain the technical/legal differences between the new Yeti design and the Commencal Supreme prototype, which was released a few months ago. I got a lot of comments questioning their similarity, and while they are super similar, they’re not exactly the same.

First, the Yeti. Were going to talk about the two links attached to the seat post tube; the lower link 315 and upper link 317. The lower link 315 uses three pivots, one attached to the seat post tube (320), one attached to the chainstay (324), and one attached to the center link (325). The chainstay pivot 324 is below the center link pivot 325, and the seat post tube pivot 320 is forward of both other pivots. Easy.

Now, the rocker link 317 – this is where the difference is. Going clockwise, the order of pivots are: seat stay 323, center link 326, and shock (undefined). In short, the center link pivot 326 is between the seat stay pivot and the shock pivot. It you want to get even deeper, the center link pivot is above the seat post tube pivot 321, in an uncompressed state.

Alright, now the Commencal. I flipped this image so the orientation is the same as the Yeti. Doesn’t really matter that it’s non-drive side. Again, Commencal are using the three-pivot lower link in the same orientation as Yeti. If I was prosecuting this, I could find a technical legal difference like “In an uncompressed state, the [Commencal] center link and lower link pivot sit below the lower link and seat post tube pivot” or something like that. But, for all intents and purposes, they’re the same between the two bikes.

God damn I love this bike

The rocker link is where we’re focusing. Notice how the center link pivot is now lower/behind the the seat stay pivot, using the same clockwise orientation system as before. Also note this pivot is below the seat post tube pivot. So, the clockwise order of pivots here are: center link, seat stay, then shock. I’m keeping the numerals the same between the two images so you can see the change in location.

If I were to overcome the Yeti patent with Commencal’s design, I’d say something like “Pivot 1 is pivotally uninterrupted and connected to Pivot 3” or some shit like that. Nevermind the fact that the center link on the Commencal is a ‘single piece’ (I know it’s two, but not really two) and the Yeti’s is two links, that really doesn’t matter. That would be super tough to argue as novel.

This is technically different and unique between the two, so both of these designs don’t clash, legally speaking. As far as kinematics, idfk. The only thing I’ve gathered from numerous patents and articles is that no one developing a 6-bar system is claiming it’s  ‘better performing’, at least it’s not the primary goal. They always say this system ‘separates kinematic forces’, meaning less compromise during development, which is an engineer’s wet dream.

And that’s really it. We could nit-pick during prosecution and get both of these granted (assuming they were compared to each other) pretty easily, but this is the big difference. Both of these designs would easily overcome each other with very little compromise to the claims.

Last thing, I refuse to believe Yeti are releasing an E-bike with an external battery. The document covers the suspension only, nothing else. And based on some comments I’ve gotten, it’ll be an internal battery system.

9/8/21 Edit: I’d also like to point out that Yeti are patenting their IVC migration paths, not the physical IVCs. In short, they’re defining the reversing IVC, like the Switch Infinity. It’s possible these two designs would never even reject each other.

Photo Credit Pinkbike and Ross Bell

3 thoughts

  1. Kinematics thoughts off the top of the dome:

    Commencal is all about making that virtual high pivot happen: the dog-bone link is always pulling the lower link up and lengthening the effective chain-stay, giving that high-pivot rearward axle-path feel but combining with the horst-link to maybe minimize chain growth later in the stroke.

    Where-as it looks like the on the Yeti the dog-bone might “cam over” past the upper link’s main center pivot and let the lower link pivot downward, kind of like how the Switch systems would raise then lower the main swingarm pivot. Since the Yeti’s lower link is pretty close to horizontal, the chain-stay length won’t be effected a whole lot, but combined with the Horst link, I’ll bet they can dial both the chain-growth and the anti-squat to the Nth degree and really tune it to match the motor: gobs of traction without too much bob.

    To me, both definitely seem to be about separating acceleration-induced squat or anti-squat (the rear wheel pushing forward against the mass of the bike and rider) and chain-growth and chain-force-induced anti-squat. I’ll bet without a motor the Yeti would feel super active with a lot of bob, but with the motor smoothing out the chain-force, it’ll stick the wheel to the ground and (incoming pun) “just motor along” regardless of what hits the rear wheel.

    For patent arguments, Yeti could use the dog-bone link’s rotation as a differentiator: it’s going to rotate generally clockwise, while the Commencal’s rotates a bit CCW but mostly just translates upward. Kinda like VPP vs dw-link: counter-rotating links vs same-rotating links.

    But hell if I know, I’m a software engineer, not a suspension engineer, haha.

    Liked by 1 person

  2. To me the Commencal will have a much greater tendency for the rear axle to move backwards on initial compression, than the Yeti. This would be better for square edged hits. Both seem to be running idler gears for the chain so the effect they have on reducing bob or pedal feedback on compression are anyone’s guess!

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