Can’t I’m at work 
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Moe, this is really interesting and I’m excited to hear more about how it performs in real world riding.
I would point out that this video is potentially very confusing to people trying to understand the “RTC” principle, because as you have vise gripped weight on there, the OG 3 links would perform the same. Perhaps if you put two weights onto the offset axles themselves and demonstrated vs non-offset standard 3-links, the RTC principle would be more apparent and more difficult for people to misunderstand. It certainly took me a minute to figure out how the offset was making any performance difference in your example at least.
Cheers.
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To me it appears to be negative rake, which is not a bad thing. The low rebound characteristics of 3 links could handle negative rake very differently from other trucks, so I’m excited to hear how this progresses.
So this adapter is for the caster angle ? Weird to see it play out without movement. And I’m sure other @RipTideSports bushings with more rebound will also help.
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Not really caster either. Think about a shopping cart wheel. With caster you need a directional force applied to an offset pivot center.
With RTC the riders stationary weight determines the amount of return to center force.
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So the weight in the video was the represent the motor weight or the riders weight/force. Video makes me question if I even know how 3 links work lol
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i believe in real steering terms the effect your offset axles cause would be kingpin inclination.
but i don’t think there is terminology with skate trucks to explain it nor do i believe your trucks follow skate truck principles
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Doesn’t kingpin inclination induce camber upon turning? I thought 3-links always have axles parallel to the ground plane
they do, i was talking in reference to car steering as i don’t think skate trucks have a term for the effect . kingpin inclination reduces camber on the outside wheel while increasing it on the inside wheel, but it also creates a mechanical return to center.
with gokarts and over non suspension vehicles it also causes the inside wheel to lift up creating more grip on the outside wheel.
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This is more along the lines of where im at as well.
From a deck height to ground measurement at zero steer to full right or full left, the deck rideheight raises as you steer and lowers as you return back to center.
The “Other planet trucks” had a similar effect using ramping cams and a channel pivot.
I suppose there needs to be terminology defined for this. It is neither castor or rake…
RTC (Return to Center) or Centerforce will do for now.
@CHAINMAILLEKID probability has the answer.
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If all you’re doing is changing the axle position relative to the pivot axis, then its changing the rake.
So looks like negative rake to me.
Negative rake does have that raising center of gravity, and that return to center action.
Most other trucks also have an effect by moving the axles further in or out along the pivot axis. That’s happening here too, all that’s going to change the ride height and wheel base a little bit.
On kinpin trucks that messes with the bushing load can change the feel a lot that way too.
What you need to try is a small positive rake on the front, negative rake on the rear.
Now you can play with rake, you have to try split.
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if the rake was neutral it would still load the links recreating a return to center effect.
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I’ll have to look at it more closely.
No it wouldn’t. Return to center effect doesn’t exist without rake. If the rake was neutral, and there were no bushings on the center balljoint, the truck would be stable at any angle and not return to center.
Moe’s video demonstrates this well. The offset axles are modifying rake. The return to center, is a property of negative rake, because the center point is the most stable point when an axle with negative rake is loaded.
This is a simple way to think about the impact of rake on truck stability. If you watch Moe’s video above, you’ll see the truck behaves as you would expect it to when modifying rake. Negative rake creates stability in the center, and positive rake creates instability in the center. Rakeless trucks will be stable at any point. Put weights on the axles of a standard rakeless 3-link, and it will sit where you tilt the truck.
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Oooh split rake that would definitely be very interesting
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After some testing in solidworks I have made some shocking discoveries…for every 3 link setup (including positive and negative rake) there is a way to replicate it with an RKP that has a 1:1 deck roll to axle yaw mapping, and none of them pitch the axle by an appreciable amount
Rake and RTC boil down to exactly the same premise of whether the fixed point of the axle sits above (stable) or below (unstable) the plane of rotation (coincident to the axis of rotation of the hanger and parallel to the axle)…if you have anything that spins and the axis of rotation is not vertical, the center of gravity will alway act to rotate the object until the center of mass is directly below the axis of rotation and the same thing happens here
Please do some testing on your own!
Assem1.zip (2.9 MB)
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Yeah I made the same discovery in CAD the 3 links just pivot like an RKP.
However I do wonder if the cantilever effect from an offset axle causes additional friction on the 3 links from loading up the rose joints which may help to dampen oscillations
Ok class.
Neg rake or Pos rake?
What do we have here.
Fig2
Neg rake or pos rake?
Both setups make RTC
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From a drag standpoint you want neutral front and negative rake rear, but I’m not sure how much of an effect stuff like that would have