Building a cargo trike
 

Hey guys,
How y'all doing? I'm new here so bear with me
I was advised by a senior member to post here for your advice.
I have been impressed with cargo trikes and want to build my own as a hobby. I'm an engineer but have never made a bike before.
Can someone please help me know where to start? Are there any building plans available online for the chassis?
What I am considering is a 3-wheeler which driver in the front and cargo in the back. Would love to know your inputs, suggestions, ideas, concerns etc.
Thanks a ton for your help!

Hughes

The best place to start might be to get a scrap bike and modify the rear end, at least to make a prototype. You will need something steel and the cheaper the better from the point of view of it being easiest to weld to. Then I would just use 1.6mm wall square or round mild steel tubing to construct the back end and make it up as I went along. I guess you want stub axles so those will be interesting. They must be something you can just buy for other trikes.

That's not a very popular configuration because of the drivetrain issues it introduces.

Is there a reason you aren't considering the bakfiets design? Lots of help, plans, and kits there.

It's fun looking at pictures of cargo bikes. I see that putting 2 wheels on the front is much more common than the rear. https://www.google.com/search?q=carg...w=1288&bih=668

The steering is more complicated with the box on the front, especially if you have two wheels. But it's better for keeping an eye on any children or valuables you might have in there.

There's a guy on YouTube called Phil Vandelay who's made quite a few of the kind with the box at the front. The steering usually involves a rod with a bend in it and a Heim joint.

The mechanism for steering and also trying to keep the weight down on a bakfiets bike is tricky. But I don't think the mechanism is too difficult. Americans call Helm joints "rod end bearings"
I watched Phil Vandelay's cargo bike video, but he has a lot of neat projects. He sells plans. There is also a company from Germany that sells plans to make a bakfiets style bike using bolted aluminum tubing, which might be interesting for people that don't weld.
Don't remember the name right off.
Certainly a few hits for cargo trike on youtube https://www.youtube.com/results?sear...cle+cargo+bike

Thanks guy153! Yes, this seems like a nice starting point. Will give it a shot :)

Thanks unterhausen, the reason I am not considering the bakfiets design at the moment is because I feel that the steering would become complicated for a newbie like me, but yes, I would definitely want to give it a try once I become a little well-versed with building the simpler model. Can you please help me understand which drive train issues did you mean? Perhaps I can look out for those :)

Thanks to both of you again.

Instead of just driving a rear hub as on a regular bike you're now driving some sort of solid axle. So you will need to machine some custom components for back there, especially if you want derailleur gears and a freewheel.

I guess it might possible to weld half shafts onto the flanges of a bike rear hub if you can find a steel one. They're mostly aluminium.

It's difficult to say which is harder: the custom drive train for one way round vs the custom steering for the other. Two wheel front steering might be rather fun to do and you could do the proper Ackerman geometry. Whereas a rear two-wheel design will always be compromised because you aren't going to want to have a differential.
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After I posted that, I wondered if you were interested in having the two wheels in front or in the rear. If they are in the rear, you need to have some kind of differential or one wheel drive. It's not that these problems haven't been solved before many times.

the bolted together design is from XYZ corp. I forgot they have a trike XYZ CARGO bikes made in Copenhagen and Hamburg
That might be a good design if you just want to get experience.

Before you settle on a trike you should ride one. I personally hate them because they are difficult to ride on a standard street with a crown. I have a longjohn style cargo bike and the streering mech is actually quite simple. It rides like a normal bike if it's empty or full of kids.

Did you make it? Do you have pictures?

I did not make it, a friend of mine did. He worked under the logo Cycletracks for a while but I'm not sure he is still doing it.

https://cimg9.ibsrv.net/gimg/bikefor...dd1fef4be2.jpg

Hey Cynikal,
Thanks for the input. I think for starters, I am going to stick to the trike. Having worked in the auto industry, the word "chassis" is more familiar for me than a "frame" (Sorry, it's an inside auto joke :D ). But yes, would love to try other variants after the trike.
I am still trying to figure out the differential part, although guy153 gave some really good advice above. Still would be cool to get a basic chassis design to begin somewhere.

an automotive engineer should be able to do something like this :)

OOh, that is interesting :) :)

2 wheels in front put you solving the same issue as cars 2 different radius arcs for wheel nearer or further from the apex of the corner..

Christiania trikes the whole cargo box has a central pivot .. under it,,


https://farm6.static.flickr.com/5262...1862a980_o.jpg

If I remember correctly, Schwinn once sold a trike conversion kit that included a differential and rear axle. An internet search did not turn up anything, but I found this: https://www.utahtrikes.com/UTCAT-5016.html .

https://cimg4.ibsrv.net/gimg/bikefor...a724040346.jpg
Here's a variation of the typical front box cargo bike which uses a simpler steering mechanism. Basically 2 aheadset stems connected together. Drawback though is you need a top tube connecting the 2 head tubes together. May interfere with a high load though.

Hey guys,
How is the weekend going for y'all? Hope all of you are safe and well.
So was planning the cargo bike today (weekend..phew!) and I was hoping to have it comply with the standards EN15194, EN14764 and the newly created DIN 79010:2020-02 Cycles – Transportation bikes and cargo bikes.
I looked up online and all these cost about 250 dollars each. Now I understand they work a lot to make these, but is there a lite version (read "free") of these things available for hobbyists like me?
Yes, I understand it sounds stingy, but I cannot afford to spend 250 dollars at this moment :)

I'm always disappointed by those standards, they charge that much because they can, not because there is that much value inherent in them.

I would suggest you go to an engineering school library, but they probably wouldn't let you in.

this site may give some ideas there have a number of designs

https://www.atomiczombie.com/timberw...rike-diy-plan/

https://cimg3.ibsrv.net/gimg/bikefor...0f10fca9c9.png