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VeMoo leaning tadpole trike

March 23, 2025 — BarryK

I'm always interested in new tadpole trike developments. At one time I looked around for enclosed or semi-enclosed tadpole trikes (or quads), and in 2023 posted this report on the Pedilio and Veemo:

So many of these startups claim to be starting production "soon", or to have started limited production. But then, years later, they have faded away. Just a quick glance at the Veemo site, it looks like they have reached production.

I recently discovered another startup, the VeMoo trike; this one is particularly interesting, as it is a leaning design and also full-suspension. It is partially enclosed. Here is the website:

https://www.vemoo.fr/en/home/

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The VeMoo is intended to be in production in 2025. They are taking pre-orders, but I don't know the price.

I very much want to know how the steering and leaning works, but cannot find the precise details. There are videos, but they don't show much detail:

https://www.youtube.com/@VeMoo_Mobility/videos

However, I got a clue how the leaning works from this video by the "Laidback Bike Report" of the VeMoo at Spezi 2024 exhibition:

https://www.youtube.com/watch?v=mf6iN0zQ8Aw

The guy showed how it tilted, just by pushing it sideways. This means that it is a weight-controlled leaning; so you shift your weight to the side and it will lean. This is a "Type 1" leaning mechanism, that I posted about recently:

However, the website describes it as a "pendulum suspension". From this I deduce that when sitting in it, it will have a natural tendency to stay vertical. But, lean to the side and it will tilt.

I cannot say how effective this leaning mechanism is; anyone who has ridden one, let me know! You can post in the comments section of my YouTube channel, or send me an email.   

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Meanderer trike project intro video

March 22, 2025 — BarryK

Previous blog post in the new "Meanderer" leaning full-suspension build-from-scratch DIY tadpole trike project:

The intention is to make videos on YouTube as the project progresses; to get the ball rolling, I have created a brief intro video, that outlines what the project is about.

Don't expect much though; this is the first time that I have video-ed myself. Used my phone selfie-camera, and when played back, realised two main faults; firstly that I should have been looking at the camera not at the screen, and secondly shouldn't have wobbled my head around so much.

Anyway, here it is:

"Meanderer leaning full-suspension tadpole trike PART1"
https://www.youtube.com/@meanderinglight/videos

I'm not bothered about my photogenic lack, nor faulty technique, as this is introducing a technical project, and in future videos most of the time the camera will be pointed at the work underway, rather than myself.

Did start to learn how to use Flowblade video editor, but haven't progressed very far.   

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Meanderer trike front suspension plates

March 19, 2025 — BarryK

Previous blog post in Meanderer trike project:

The front of the trike will have suspension, with swing-arms (also known as A-frame or wishbone arms) and shock-absorbers. The swing-arms will hinge on two plates attached to the frame of the trike. The frame is a 25x25mm square tube, 3mm wall thickness. The plates are 110x175mm sheet, 5mm thickness. There will be extra bracing with angle, as illustrated:

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More construction details will be revealed, but for now, contructing just the two plates. They have holes and 50x50mm cutout:

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...regarding those 6mm holes; in fact, I used a 4mm drill bit, the intention being to later tap a thread for m6 bolts.

In an earlier blog post, there is a link to where I purchased the 5mm thick sheet. However, in retrospect I would have bought 6mm sheet, as that is more common and discovered available locally at a reasonable price.

I marked out the holes and cutout, then cut the plates on a metal bandsaw:

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...yes, I know this project is intended to be do-able by anyone in their home workshop; a handheld jigsaw does the job OK also. In fact, I found that a jigsaw was the best choice for the 50x50 cutout.

Then put the two plates together, firmly clamped on a block of wood, and drilled the holes with a hand drill (after centre-punching):

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...took the precaution of driiling 2.5mm pilot holes first, for greater accuracy. For the 8mm holes, it would also be good practice to drill another intermediate hole, say 5.5mm. The reason is, large drill bits tend to wander off-centre, and a pilot hole keeps them centred.

The 50x50 cutout... expected that to be tricky. We started to do it on a large metal router at the Men's Shed:

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...no, not appropriate for a DIY guy in the home workshop! Besides, we decided that it is a clumsy way to do it. Instead, used a hand jigsaw. Firstly, took off the protective plastic, then re-marked the 50x50 cutout:

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...the four 8mm holes are the suspension hinges for the swing-arms, and the 50x50 cutout has to be symmetrical. I drew lines on the outside of the 8mm holes, to help with measuring symmetry.

I had previously drilled 3mm holes in the corners of the cutout, which we thought might be useful. But in retrospect, probably not. Or maybe just smaller, like 2mm.

Anyway, got the cutout re-marked, then drilled 10mm holes in opposite corners, as close to the marked lines as possible. Then used a square file to make the corners square, for insertion of the jigsaw blade. I used one of the jigsaws in the Men's Shed; it already had a blade in it, didn't know if for wood or metal, but it did have fine teeth, which I wanted:

img7
 img8

...yes, nice cutout. Just cut one plate, then used that to re-mark the second.

A bit of fine-tune filing was required, then it was able to slide snuggly onto the 50x50 tube:

img8

...notice those two holes in the bottom corners; countersunk. The two closer-in are the 8mm holes for the swing-arms, the two outer holes were supposed to be drilled with a 4mm drill bit, for later tapping for m6 bolts. However, a lapse in concentration and I drilled 6mm holes. So decided instead they will be countersunk bolts.

So, what's next...   

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Front wheel hubs for tadpole trike

March 12, 2025 — BarryK

Continuing the new "Meanderer" build-from-scratch recumbent full-suspension leaning tadpole trike project, here are recent posts:

Using bicycle parts where possible, is good; however, there is a problem with the front wheels. A bicycle front wheel has support on both sides of the axle, whereas only on one side on a trike. This is a problem; we need a certain type of bicycle wheel hub, known as a "thru hub". This has a shaft, or axle, that goes right through, usually of 12mm, 15mm or 20mm diameter.

We really want the 15mm or 20mm axles, which is another problem, as they are only used in premium mountain bikes. So, finding that type of wheel secondhand might be difficult. Suitable wheels could probably be purchased from a bike shop, or maybe a cheap secondhand tadpole trike could be located.

My first trike project, now mostly completed, was a cheap trike that I modified, with front suspension, etc. I'll refer to it as my "current trike". It has wheel hubs for a 20mm thru-axle:

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I got a bit confused, as this hub is only about 92mm wide, whereas looking online, available hubs are 100mm, 110mm, or 135mm wide. Nothing under 100mm. So I bought a couple, 15x100 and 20x110, to examine. After they arrived, I realised something; they are not "really" that wide.

To explain, here are photos of the hubs on my current trike:

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And the inside:

img3

...it looks very much like some extensions on both sides has been removed. The width of the inner alloy tube is only 82mm, and total width of the hub is 92mm.

Yes, the two hubs that I purchased have plastic extensions on both ends, extending the width to 100mm and 110mm. But, cut them off, and the with becomes 92mm and 84mm.

This is one that I purchased, 15x100, meaning 15mm diameter thru-axle and 100mm hub width, for AU$28.39 (plus 10% GST):

https://www.aliexpress.com/item/1005005254533680.html

The other, 20x110 32-hole, for AU$41.59 (plux GST):

https://www.aliexpress.com/item/1005008343824211.html

20mm axle hubs are somewhat rarer and much more expensive. Photo:

img4

I reckon those plastic width-extenders could be cut shorter. So, I plan to build the axle length on the Meanderer wheel knuckle for a 92mm wide hub. That will handle all three of the above hubs. Maybe make the knuckle axle a bit longer, and washers can be used if required.

A note about a tadpole trike; we need to be careful about overall width. For the Meanderer, I want total width to be no more than 730mm, so as to fit through my front door, and motel doors when touring. So taking 10 - 15mm off the hub is important.

If you want to read more about mountain bicycle front wheel hub types:

https://www.bikeradar.com/advice/buyers-guides/mtb-axle-standards

Should also mention, there are axle diameter reducers available. I bought this one to evaluate, 20x100 to 15x100:

https://www.aliexpress.com/item/1005006596535497.html

Plan to build the wheel knuckles soon, and there will be a blog post when that happens.    

Tags: light

Universal-joint for Meanderer trike

March 03, 2025 — BarryK

Earlier posts on this new trike built-from-scratch project:

In the "swivel-coupling" post above, I did post plans for a swivel-coupling, or universal-coupling, but withdrew it. Have reconsidered, modified the plans, and here it is again...

Bought a little universal-joint off Aliexpress, for a 10mm shaft. These are available from many vendors:

img1

However, not happy with it. There is some sloppiness in the movement, and I would like it to have replaceable bearings. Hence a design to make one...

In SolveSpace, it is possible to create what is called an "assembly", multiple 3D components put together. However, I have found that to be very difficult. So, have designed the universal-joint in two parts, then mentally visualized how they would work when put together. Here is Part-A:

img2

The aluminium sheet is 5mm thick; a couple of local stores only had 3mm, so I bought it at a premium price off Aliexpress:

https://www.aliexpress.com/item/1005003726781313.html

Though, likely there are local aluminium fabricators that would have 5mm offcuts. The main block of aluminium is the 22x22 square, that I provided a purchase link in the previous blog post.

The 8mm hole will have a brass flanged bush, the 12-8x6x6 from here:

https://www.aliexpress.com/item/1005005073792086.html

Actually, I have referred to the bushes as made of brass, but it is listed as "copper-based alloy"; whatever, it is very strong, not soft like copper, and has a different colour than brass.

One thing; to get sufficient flexibility, those square corners near the 8mm holes, will need to be rounded off. That will be easy enough; just cut off the corners and round off with a file.

Here is Part-B:

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Again, a piece of the 22x22 square aluminium.

I'm having to mentally visualize whether it will have adequate flexibility; seems OK.

In the above diagram, the 5mm holes are for tapping a thread for an m6 bolt. In the first diagram, the 4mm holes on the sheet will be drilled out to 5mm, and in the main block tapped for an m5 thread. The m5 bolts will go through and bolt the sheets onto the main block. There will be m5 grub screws to lock the 10mm rod.

Note, m5 standard thread has a pitch of 0.8mm and the required drill size is 4.2mm. So a 4mm drill bit is a bit small. Might have to experiment to cut a m5 thread in that smallish hole.

The 5mm thick sheet hasn't yet arrived; however, tomorrow can manufacture the three 22x22 main blocks (there will be two Part-A).

Here is the SolveSpace design, files renamed with a false ".gz":

https://bkhome.org/news/202503/images/t2-universal-joint-parta-2.slvs.gz

https://bkhome.org/news/202503/images/t2-universal-joint-partb-2.slvs.gz  

Tags: light

Progress planning The Meanderer

March 01, 2025 — BarryK

I don't know if that name, "The Meanderer" will stick, for the new full-suspension leaning recumbent tadpole trike. Here are recent posts:

...in the post of Feb 28, I posted plans for a swivel-coupling, then changed my mind and removed it. The swivel-coupling, or more correctly a universal-joint, needed a bit more thought. For other components of the trike, waiting on parts to arrive. So what can I build now? -- can build the swivel mechanism for the shock absorbers.

Getting the parts together, need various lengths of aluminium extrusion. Want 50x50x3 mm square extrusion, about 3 metres. Not available at Bunnings (our main hardware chainstore here in Australia), so looked online. Got a quote from one company, but this is a big company and 50x50x3 is sold in 6.5m lengths. They will sell by the metre, but about double the price. Then they wanted AU$150 to deliver, about a 50 minute drive away.

Hmmm. Found a local little family business; they had 50x50x3 in stock and were happy to sell by the metre, and very cheap. Pickup only, so I rode my ebike there:

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...don't laugh! Was able to ride the bike with that load.

The proposed tilting is by a swivel-bracket where the shock absorbers join, see this blog post:

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In SolveSpace, created a design for that swivel-bracket. Here it is:

EDIT 2025-03-05:
Following diagram and SolveSpace file have been updated:

img1

The central post is 22x22 mm, with a 8mm hole through the middle, so not quite solid. Bought it from here:

https://www.aliexpress.com/item/1005004854415047.html

The diagram shows five holes of 10mm diameter. The four at the top will have brass bushes, to take 8mm rods for the shock absorbers. There are bushes available with 1mm wall thickness, and it is a good idea to put those in, so as to have replaceable wear surfaces, rather than wearing the aluminium holes. The 10mm hole at the bottom of the post will not require a bush.

Have the 22x22, but want sheet 5mm thick; only have 3mm. Have some 5mm on order; have to wait until it arrives.

A note about the spacing of the two sheets. The required spacing depends on what shock absorbers are used. I'm not sure, but I think that motorcycle shock absorbers are 19mm, whereas those on bicycles and scooters are 24mm.

Just remembered also; the bicycle shock absorbers require 8mm bolts, the motorcycle type require 10mm. At least, for ones that I have looked at.

Here is the SolveSpace file, gzip-compressed:

https://bkhome.org/news/202503/images/t2-susp-swivel-2.slvs.gz 

In the above diagram; the 10mm hole at bottom of the post will have a 10mm rod through it. There will need to be grub screws either side, as the swivel-bracket is required to be locked to the rod. Likely I will drill either 4.2mm holes for a m5 bolt, or 5.0mm holes for a m6 bolt (the diagram shows 4.0mm). Probably the smaller. Note, the rod is required to be locked to the swivel-arm as that is part of the tilt control; will probably drill the 4.2mm holes slightly into the rod, before threading, so as to have very positive locking of the rod.

The 5.0mm holes are for m6 bolts, so will need to be drilled-out to 6mm through the sheets, and tapped in the post.

Oh, and to round off the explanation a bit more; that central post has a 8mm hole right through, and at the top a m8 bolt can be slid into it to lock tilting. There will be aluminium sheet above the swing-arm, with a 8mm hole; slid the bolt through that and into the post, then no more tilting. Just in case the rider doesn't want the tilting mechanism, that is how easy it will be to disable it.    

Tags: light

Steering swivel-coupling for new trike project

February 28, 2025 — BarryK

I have started a new project, to build a full-suspension tilting recumbent tadpole trike from scratch. Here are earlier posts:

Cannot guarantee that will finish this project; main interest right now is the technical challenge of implementing the new steering and tilting idea, rather than the end result. Thinking of all those DIYers out there, having detailed plans for parts of a trike will be helpful. This post is one component, the steering swivel-coupling. Measurements and details in this blog post, but there is also intended to be a video on YouTube, showing how it is contructed with a link back to this blog.

The new trike needs a name, so how about "The Meanderer"?

EDIT:
I decided to remove this first contruction post, as it is a bit premature. I'm still thinking out some details.

    

Tags: light