3-Link Truck Designs

I believe Lacroix is working on something… If I remember right it was on the Carve UK interview from a week or two ago.

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I think he said he’s not even into prototype stage yet.

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Thanks @MoeStooge for posting about this awesome truck design, I’ve been tinkering with this since I stumbled across some of your old posts during my covid lockdown…totally DIY here :wink:

I’ve got a question for the 3-link/NKP gurus regarding linkage geometry and how it relates to truck turning and board lean angles. Let’s use this rudimentary 3-link design of mine (it’s rough, but hopefully the idea comes across).



The control linkages (rod ends) come off the base plate at a 45 degree angle to join the axle. If you measure the angle of the linkage relative to the ground plane (or skateboard deck, as I’ve seen @MoeStooge reference in his posts) orthagonal to this 45 degree base plate angle you can see there are two possible angle postions: 45 and 20 degrees.

If you measure the same linkage angles (again relative to the ground plane), but are looking at the trucks directly from the side, the angles are now 54.7 and 27.2 degrees respectively because…maths, I guess (fucking complex 3-dimensional trigonometry that gives me a headache thinking about).

Here’s another screen grab that shows both angle measurements (first time I’ve found a use for 3d sketches in fusion 360 :sunglasses:)

So my question is, which angle is the correct one to use when describing these as “xx degree” trucks? My personal, very limited experience here with barely ride-able, deathtrap prototypes is that the angles of 45/20 degree as it describes this truck is more accurate.

What do you guys think?

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Yea, totally man

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Keep in mind. Extreme lateral rod angles also affect lean tilt ratio and the radius rods fulcrum over the axel.
In rigging, 30deg is what we refer to a critical angle. Past this point is where applied force multiplies for every degree lower than 30. The ability to control axel function reduces as you Increase the radius rod lateral angle to the axel. I prefer the lateral angle in the 60 to 80deg from axel centerline window with the axel side rod ends as close to the wheel as the wheel allows. Your model will have increased steering ratio from high lateral radius rod angles. Downside, increased force applied to hardware to keep the axel on plane when outside forces are applied to the axel.

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Great point, thanks for the 60-80 degree tip!. Thinking about my question in regards to leverage ratio as defined by radius rod lateral angle, then I think true truck/axle turning angle is measured inline with the radius rods as opposed to side on.

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Looks very promising, dont forget the bushings on the axle, they should work great for stability.

Been a productive week at the ol Skullquacker ranch.

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This is huge!

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I really really want to give those a try.
How soon until I can get my hands on some?

Gotta say, somehow that just looks like a more developed product.

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If you’re in the Bay Area CA, you can try mine out or if you’re near SoCal you can probably try @DEEIFs or @MoeStooges. Theirs are probably far more tuned than mine

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Nowhere near Cali.

Probably going to have to wait until they’re shipping out.

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We’re tooling up to hit the market rumning.
Won’t sell a part I don’t have in hand.
Get on the inquiry.

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Two questions.
How much custom tooling do you need for this?
Seems you could be in a pretty good spot in this regard compared to other brand spanking new designs.

And how much lean are you able to get out of these trucks setup this way?
If I was to put it on a board with wheel wells and just max it out, how far could I go?

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Really really really far…

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I design my max board lean around 30 degrees…

you could do more if’n ya wants to… but stand on a board at 30 degree lean… more lean means increasing the ride height etc. I’ve accepted that trade-off for now…

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on my first set of 3-link base plates I went total blacksmith creating them…

look at @moe’s pix he’s moved on from sheet-metal base-plates as well as I have…

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I lean my board out to 32 degrees, and rail bite is my middle name.

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See abouts 30… I haven’t done the maths on a 45 degree board lean… The increase of ride height is an unattractive trade-off to me…

Figger on 30ish… Calc wheel/tire/truck articulation and 1.5 c*nunt hairs tire to board clearance and your uncle will be named bob

The OP trucks I use have the raising center of gravity thing going on. So with all else being equal, at 30 degrees of lean my board would have 1/2" more rail clearance than yours would.

Having ridden with so much lean for so long, I’m willing to give up a bit extra ride height for it.

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