In this article, we’ll be discussing a 6-Bar Vehicle Suspension Linkage with Drive Train Idler by Yeti, US publication 20210269117. The publication date is Sept 2nd, 2021 and the filing date is Feb 26th, 2021. This has not been granted yet.
As we know, Yeti are going to release an E-bike. Prior article here. Based on some messages I’ve gotten, it’ll be out in September or October. I’ve written about the new Yeti E-bike enough that I don’t think I need to write another full article, so I’ll just share the highlights with this new one. I’m also pretty sure this is about to be released so I wanted to get this out quick.
This is showing yet another variation of their new 6-bar system and E-bike with a high pivot and idler. I remember reading some comments about the ‘leaked’ picture stating they believe there was an idler (or an idler would be necessary). Looks like they might be right. This document shows a high pivot, 6-bar layout with an idler. Another interesting point is the slot(?) at the bottom of the shock. They don’t say anything about it, so all we have are pictures so we can speculate to the moon. They also say this configuration can include a gearbox.
The big takeaway here, with this entire system, is Yeti say that the 6-bar with an idler, the anti-squat, anti-rise, and leverage rate ‘…allows for greater separation of variables so that each can be adjusted or optimized [more independently].’
9A and B show the E-bike.
FIGs. 9 Eand G show close up and the general travel.
FIG 5 shows an example of what happens to anti-squat when you add an idler to this system. 800 is no idler, 900 is with an idler. So, the anti-squat lowers toward 100%, which Yeti say is ‘ideal’.
Anti- squat is typically described as a percentage value. 100% anti-squat is when the anti-squat force is equal and opposite to the load transfer force due to acceleration. As a result, the system is in equilibrium and no suspension squat occurs.
FIG. 6 is anti-rise. 701 is an extended state, 702 is compressed. They say ‘anti-rise remains around 100%, which is ideal.’
100% anti-rise is when the anti-rise force is equal and opposite to the load transfer force due to deceleration. As a result, the system is in equilibrium and no suspension rise occurs.
FIG. 7 shows the leverage rate. Because it generally falls, Yeti say this will provide small bump sensitivity, prevent harsh bottoms outs, and have a supported mid-stroke. This is a divergence of ideas throughout the entire industry, so this is probably correct and will be the general curve for every bike for the rest of time.
leverage rate is the ratio of the change in vertical wheel travel to the change in shock stroke.
FIG 19 shows anti-squat with different chainring sizes.