Lego Tilting Motor Works three-wheeler

"Jim Spanfeller" (awesomeaustinv) 07/06/2020 at 18:28 • Filed to: Legolopnik, bikelopnik

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So, a while ago I discovered a company called !!!error: Indecipherable SUB-paragraph formatting!!! that makes these really cool three-wheeled conversions for Indian, Harley Davidson, and Honda motorcycles. What makes these conversions really interesting is that unlike most three-wheeled motorcycles, these ones can lean in turns:

So it’s just like riding a two-wheeled motorcycle, but with extra grip and better braking. The only drawback is that it has a larger turning radius than a conventional motorcycle. I find the front suspension on these leaning trikes fascinating, so I set out to replicate it in Lego. This ended up being surprisingly difficult, but eventually, I figured out how to make it work .

It was quite tricky getting all of the geometries to work, and because of the way the suspension has to flex, regular Lego suspension parts don’t work in this application, so I had to make my own hubs and tie rods and everything.

The hardest part was getting the tie rods to work, because official Lego tie rod pieces 1) didn’t flex enough with the ball joints, 2) were the wrong length, and 3) couldn’t both connect at the center. That last bit was the biggest problem because it prevents the geometry from working right and makes it extremely difficult to incorporate a steering mechanism. All of my attempts with regular Lego tie rods kept jamming and interfering with the rest of the suspension, so I ditched those in favor of making my own. The solution I came up with was to use a Lego flex axle with spacers on it to limit flex and keep the center mounting point in the center:

This way, the single tie rod is rigid enough to move the wheels while keeping them in alignment but flexible enough to bend with the suspension and steering as necessary, plus the geometry works as it should because it connects at the center:

The rest of the motorcycle is something I built a long time ago and I decided to use it as the basis for this leaning three-wheeler. It features a hardtail, shaft drive, and a flat twin, so it’s most definitely not a Harley, Indian, or Honda, and I don’t think anyone makes kits like this for classic BMWs yet. They totally should, though.

I also sent this thing across my driveway multiple times and I am happy to report that it automatically rights itself just like a regular motorcycle. It is very stable at speed. I had to fetch it from under the Civic...

And now it’s photodump time.

jminer > Jim Spanfeller 07/06/2020 at 18:38

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That’s awesome, well done!

Who is the Leader - 404 / Blog No Longer Available > Jim Spanfeller 07/06/2020 at 18:40

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That is some seriously impressive engineering! I can't believe you figured that out. I'd always wondered how to use those flexible tubes.

Jim Spanfeller > Who is the Leader - 404 / Blog No Longer Available 07/06/2020 at 18:50

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Thanks! I do think this is some of my finer Lego engineering. Those flex axles can actually be pretty handy sometimes.

Jim Spanfeller > jminer 07/06/2020 at 18:53

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Thank you!

Brickman > Jim Spanfeller 07/06/2020 at 18:56

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Very cool steering mechanism !

Jim Spanfeller > Brickman 07/06/2020 at 19:04

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Thank you! That was the most fun part to figure out.

Daily Drives a Dragon - One Last Lap > Jim Spanfeller 07/06/2020 at 19:15

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Using a flexible rod for the steering is a great solution. Usually when the lego joints start binding is when I move on to something else. 

carcrasher88 > Jim Spanfeller 07/06/2020 at 23:01

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That’s pretty slick, and nicely replicated! Basically, it’s very similar to Piaggio’s MP3 line of scooters, except theirs is OEM. Sat on one at an auto show a few years back, and that thing wouldn’t tip over, no matter how much you steered it left or right...though it was only stationary. Still, quite awesome!

BoxerFanatic, troublesome iconoclast. > Jim Spanfeller 07/06/2020 at 23:08

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Something you may or may not know...

I read that Bob Mighell, the inventor and CEO of Tilting Motor Works used LEGO as a proof of concept before he built his first working prototype out of a Yamaha V-Max, as a custom fabrication, long before the production refitting kit that they now call TRiO.

I have LONG, LONG wanted something like this on something sportier than a Harley or GoldWing… although a stripped-down Goldwing/Valkyrie might not do too bad.

Yamaha Niken doesn’t seem right, with four forks, and high-mounted complex geometrical articulation mechanism.

Can Am Ryker and Spyder don’t lean, they corner flat like a car or snowmobile.

I have really wanted Honda to build their NeoWing concept... but that doesn’t seem likely to happen.

Jim Spanfeller > BoxerFanatic, troublesome iconoclast. 07/06/2020 at 23:26

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Seeing the Lego prototype on Tilting Motor Works’s website was what inspired me to build this. Theirs only had the tilting mechanism, though, and lacked steering. The main challenge for me was incorporating steering into the Lego mechanism. And I agree with you, their should totally be kits like this for sport bikes. That Honda concept is really cool.

Jim Spanfeller > carcrasher88 07/06/2020 at 23:29

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The Piaggios are very cool. My favorites are Randy Grubb’ s “Decopods” which he built out of Piaggio scooters.

shop-teacher > Jim Spanfeller 07/06/2020 at 23:36

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That is one wild model!

Also, damn you for getting that song stuck in my head!!!!

Jim Spanfeller > shop-teacher 07/07/2020 at 00:28

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:)

davesaddiction @ opposite-lock.com > Jim Spanfeller 07/07/2020 at 10:02

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Very cool!