Duality, a different approach.

[Flyboy]

This is such a neat idea and the the aesthetics are just [chef’s kiss ]. I’m always psyched to see more 2-wheelers here.

@frame

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I think the weird steering behavior of the machine is down to the huge negative trail you’ve got going on for the front wheel. This means that if too much lateral steering force is put into it by the contact patch, it’ll flip itself to one side or the other.

@Soflo

if you lean too hard too fast it’ll lock out in the opposite direction

Lateral force (with respect to the trucks) could come from friction in a hard turn, or from normal force while the machine is leaned over.

@Soflo

Green Lacroix in the wide position on the rear and blue lacroix on the wide position in front.

If using a harder front bushing helped the issue, I’m guessing this is why. Or is that front bushing softer that what you started with? I’m interested in whether you’ve tried a bushing split where the front is harder than the rear.

@Venom121212

That lockup is where I think the waterborne surf skate adapters would either save you or exacerbate the issue.

I think it will be harmful here, since it adds another steering axis, which will still be aft of the front wheel. So still negative trail, but without bushings to stabilize it.

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I think the reason your trucks can turn at all is because of the square tire profile. Having the sidewalls spaced out so far gives you something to lean against, just like having a skate wheel mounted to the end of a truck. You put your weight on the edge of the deck, the contact patch pushes back under your feet, and that allows you to squeeze the bushing.

That last diagram ended up cluttered so I stripped it down.

It’s like squeezing spring loaded pliers, basically.

@Soflo

I think i need to move to a tire that is more round on the rear so the board rolls onto the sidewalls easier, the current tires are pretty square and hard to lean on

Which is why I think that using round tires will hurt your ability to steer. If the contact patch stays closer to the center, it’s like trimming down one of the handles of the pliers, or using hard bushings on super narrow skate trucks. No leverage to compress the bushings, so the board leans over without steering.

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This might be what you want for the front, since the front could be causing the static instability that makes the board lock out. The rear tire has positive trail, but only steering the rear tire can create dynamic instability that makes the board wobble.

@Ash

the other potential solution is to do like what 2swift does and have metal plate to bolt into the mounting holes and metal tubing arcing around the front tire with a metal sheet welded on the end so the tire can be mounted the opposite direction.

I second this, to guarantee you have both static and dynamic stability, you’ll need to mount the front truck in ahead of the wheel instead of behind it, and make sure the pivot axis points at the ground in front of the contact patch. You may be able to use a steeper front angle and loosen the bushings to get more maneuverability at that point.

This is an interesting problem because the skateboard aspects of the machine are stable (steering the trucks on the sidewalls), the bike aspects are unstable (steering the front wheel through leaning), and the two sides are fighting each other right now. I can’t say for sure that I’ve got it all figured out, but I hope this advice helps you choose the direction you wanna go. I’m definitely staying tuned for this!