This is the who what where when and why for the 3-link NKP truck.
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At the start the idea was a chromoly tube chassis e-board with adj RKP truck angle mounts. In speed testing tuning tilt steer ratio is a must along with reducing board twist.
![IMG_20170513_082355632|690x388] (upload://kRhuS7YVqq3ZsqMjlmUTlU8qQU.jpg)
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On the single motor setup, truck walk was prominent under braking and acceleration made life over 30mph interesting. Eliminating truck walk became the next priority… A widened axle to accommodate dual drive. The first rendering still used a kingpin and traditional bushing
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First rendering Front truck utilized a spherical bearing without bushings. Had this no bushing setup over 35mph. Wasn’t bad, wasn’t great. Bushings had to happen.
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digging the No King Pin 3-link nomenclature…
first pic looks rad bro, are they cupped washers?
Top pic, washer slight cup on the outside taper step on the inside. A special thanks to @Alphamail and Riptide Sports. Brad has played a big hand in bushing/washer setup and development on this project. It’s amazing how much change in feel a washer or bushing shape can make.
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FKing awesome Bro! could not be happier, and can not wait to see what comes next! props to Brad aka @Alphamail for steping up to contribute to R&D
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will they work w hubs? can the axle be torqued without it locking up or effecting the steering? I still don’t understand how these really go. some of those rods are squishy and some solid it seems.
Next phase was to make an axle that was independent from parts. The idea was to incorporate the center spherical bearing with a mechanical connection to the axle and incorporate bushings that could be preloaded. Being able to change axle width and re use motor mounts, rod pick-up points bushing clamp and associated hardware was a must have.
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Hubs are a definite plan for this setup. Counter rotation under acceleration and deceleration is zero. The radius rods and the center spherical bearing eliminate truck wind-up. Hubs are going to work bitchin. Can’t wait for hubs…
Testing was going well, making stable speed near 64kph or 40mph “What about wood?” What a guy I ride with said. Same setup with some fabricated base plates. The width on the axle was determined by my drive system and the 100mm inrunners. If we used hub motors we could squeeze a 165mm hanger out of it I’m sure. The first wood bolt on set. Ride height, tilt ratio (deg), axle alignment all adjustable. ! That’s a 4200w single that made 34.2mph on 8s at SPD1 with the neighbor kid Ian riding it. IMG_20170715_174816143_TOP|690x388
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Still with an inferior bushing setup on the 3-link, Geared for 50mph the raceboard made 44.7mph 72kph with a 200 meter or 600’ start-up shut-down area at SPD1. Straight and stable on 8400 Watts.
72kph run at SPD1 https://youtu.be/gKbogLAs_ac
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hows the steel tubing board feel? i imagine it feels like steel and i think that could be nice. i like the look of most of the aluminum decks I’ve seen but don’t trust them to not eventually crack but a steel deck with the steel rebound sounds pretty ideal. steel tubing is pretty cheap i think but making it must take a lot of work. looks really nice for the large part.
i still don’t get how it even is turning since it has those fixed beams holding the axle.
those centrax 83 wheels? have those if youre interested.
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Dont you use any lube or similar on the gears between the motors and wheels?
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A pic with tilt input with radius rods at full angle. . With radius rods at flat or zero angle tilt to steer ratio is reduced to about 2degrees
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The cool thing about the 3-link system is that the trucks feel the same all the way through the turn. Unlike regular RKP trucks that feel tighter as you lean. Weird feeling but definitely smooth.
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That beast is screaming for a mad max style bumper to protect the links.
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Welcome back @Wanderer!! Haven’t seen you in a while! Still wondering what happened to that badass build you were working on…
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The rods holding the axel in place have a spherical bearing or heim joint on each end allowing each end of the rod to rotate on a pitch, roll and yaw axis…
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Current phase on the raceboard ended with a very wide 11 1/4" (286mm) axel to accommodate the 10400w motor and wheel upgrade for SPD2. The V1 tube chassis was outgrown and I’ll proportioned to the wider axles and larger wheels.
In all honesty the V1 raceboard deck no longer had the leverage in a hard turn to match the wheel grip and added axle width. V2 raceboard settled with a 42" (1067mm) wheelbase and 11" (279mm) wide deck. The size change made for a more proportionate look and function. I was concerned about the wheelbase killing the turn radius but with the arm angles up it made easy work of the hairpin turn at SPD2.
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