A concept I'm working on

Hello all,

I've been riding/modifying/building electrical bicycles for the last 18 months now, and I'm ready for a new challenge.
But I'll need some advice. I meddled a little in tinkercad and made a rough sketch of what I was thinking about.

Inspired by utility bikes like the Unimoke and this bamboo design by Calfee I'm thinking to do something similar with Guadua bamboo. This particular species is tougher than steel so it should work just fine in this context.

The joints would be held together by hemp resin, but this might be hard to come by in eastern Europe where I live so if anyone knows a similarly strong resin that can bind bamboo pipes together using a different material, please mention it!

As for tire size, I'm thinking 20"x4", but maybe I'll use a similarly sized but stronger moped wheel and tire size.

I have good experience using 48V 500W engines, so I think I'll stick with that in this case also. Other electronic aspects like the battery details and controller specs I'll get back to later.

as for design details, I'm thinking about having suspension between the hind wheel, with a hinge right after the bottom bracket so it has some space to move. Since the big bamboo pipe with the saddle on it would be hollow, it would be perfect to hide the controller and some other electronics in, maybe even the battery on the backside. But if this won't fit it should go fine on the outside as well.

What are your thoughts on this early concept? Please feel free to give constructive criticism, tips, and other things I might be overlooking. Thanks!

IMANU said:

Hello all,

I've been riding/modifying/building electrical bicycles for the last 18 months now, and I'm ready for a new challenge.
As for tire size, I'm thinking 20"x4", but maybe I'll use a similarly sized but stronger moped wheel and tire size.
https://i.redd.it/k4k6yvxjpj611.png
I have good experience using 48V 500W engines, so I think I'll stick with that in this case also. Other electronic aspects like the battery details and controller specs I'll get back to later. Since the big bamboo pipe with the saddle on it would be hollow, it would be perfect to hide the controller and some other electronics in, maybe even the battery on the backside. But if this won't fit it should go fine on the outside as well. What are your thoughts on this early concept? Please feel free to give constructive criticism, tips, and other things I might be overlooking. Thanks!

Click to expand...

IMANU,

I would guess that the large center rail of the frame (between your knees) would make pedaling more difficult. I would suggest that you make a mock-up of that large pipe and install it on an existing pedal bike, to learn if a large pipe there will be okay in riding. I realize that with enough power, the pedals can become decorations, but you did ask for considerations on this design.

I believe you could get more strength (for less cost) there by using six or seven smaller pipes. A seven-tube array would be one tube surrounded by six. A six-tube array can be two tubes wide, and about two and a half tubes tall. I would favor the six-tube array, to keep the bike frame skinny.

Keep in mind the bamboo insulates heat fairly well, so anything inside it wont' really be able to shed heat. If the controller is inside, it may well overheat and fail, much sooner than normal, if not right away. I'd recommend making a heat path for the controller to a heatsink outside the bamboo.

If you are only running very low power, it may not have a problem, but when you get to hundreds of watts or more, there's enough waste heat in the controller to require shedding it.

The cheaper the controller, the cheaper the components inside, usually, and the more sensitive they can be to heat (or other environmental factors), and the closer they may be running them to their limits already.


The battery should be fine in there as long as you use parts rated to supply the power you need in the middle or low end of their capability ranges, and are not running them at the top of their output specs--doing that will heat them up...and then inside the tube they won't be able to shed that heat.

IMANU said:

The joints would be held together by hemp resin, but this might be hard to come by in eastern Europe where I live so if anyone knows a similarly strong resin that can bind bamboo pipes together using a different material, please mention it!

Click to expand...

Calfee doesn't use "hemp resin", which is a pharmaceutical substance and not a structural one. It's hemp fiber bound with some other kind of resin, like epoxy or aliphatic resin.

Normal bikes are normal for very good, well-proven reasons. Know why you're doing something differently before you do it just to be different.

Chalo said:

IMANU said:

The joints would be held together by hemp resin, but this might be hard to come by in eastern Europe where I live so if anyone knows a similarly strong resin that can bind bamboo pipes together using a different material, please mention it!

Click to expand...

Calfee doesn't use "hemp resin", which is a pharmaceutical substance and not a structural one. It's hemp fiber bound with some other kind of resin, like epoxy or aliphatic resin.

Normal bikes are normal for very good, well-proven reasons. Know why you're doing something differently before you do it just to be different.

Click to expand...

It is actually held together by a specific hemp resin applied to the hemp fiber. So do you know one?

As for doing it for being different... I want a utility bike. And I can't afford the welding equipment required for making my own aluminium frame, so using bamboo as an alternative makes sense to me. If you have nothing to add, which you didn't, just go away.

amberwolf said:

Keep in mind the bamboo insulates heat fairly well, so anything inside it wont' really be able to shed heat. If the controller is inside, it may well overheat and fail, much sooner than normal, if not right away. I'd recommend making a heat path for the controller to a heatsink outside the bamboo.

If you are only running very low power, it may not have a problem, but when you get to hundreds of watts or more, there's enough waste heat in the controller to require shedding it.

The cheaper the controller, the cheaper the components inside, usually, and the more sensitive they can be to heat (or other environmental factors), and the closer they may be running them to their limits already.


The battery should be fine in there as long as you use parts rated to supply the power you need in the middle or low end of their capability ranges, and are not running them at the top of their output specs--doing that will heat them up...and then inside the tube they won't be able to shed that heat.

Click to expand...

I've been working on a fan system to keep the inside ventilated, I'll do some tests with bamboo to see if it suffices and if it is waterproofable. I'll update on this later!

X2flier said:

IMANU said:

Hello all,

I've been riding/modifying/building electrical bicycles for the last 18 months now, and I'm ready for a new challenge.
As for tire size, I'm thinking 20"x4", but maybe I'll use a similarly sized but stronger moped wheel and tire size.
https://i.redd.it/k4k6yvxjpj611.png
I have good experience using 48V 500W engines, so I think I'll stick with that in this case also. Other electronic aspects like the battery details and controller specs I'll get back to later. Since the big bamboo pipe with the saddle on it would be hollow, it would be perfect to hide the controller and some other electronics in, maybe even the battery on the backside. But if this won't fit it should go fine on the outside as well. What are your thoughts on this early concept? Please feel free to give constructive criticism, tips, and other things I might be overlooking. Thanks!

Click to expand...

IMANU,

I would guess that the large center rail of the frame (between your knees) would make pedaling more difficult. I would suggest that you make a mock-up of that large pipe and install it on an existing pedal bike, to learn if a large pipe there will be okay in riding. I realize that with enough power, the pedals can become decorations, but you did ask for considerations on this design.

I believe you could get more strength (for less cost) there by using six or seven smaller pipes. A seven-tube array would be one tube surrounded by six. A six-tube array can be two tubes wide, and about two and a half tubes tall. I would favor the six-tube array, to keep the bike frame skinny.

Click to expand...

Thanks! I've ridden on bikes with similar rails before so I should be fine. Also the pipe looks a bit too big here. The maximum diameter is 15 cm, I think that's fine with a comfortable saddle on it for comfortable pedaling.

IMANU said:

It is actually held together by a specific hemp resin applied to the hemp fiber. So do you know one?

Click to expand...

Calfee uses an adhesive called Entropy Super Sap CLR, which the manufacturer claims is made from plant materials, but is an epoxy. It's not cheap, but you can find it from multiple suppliers.

I made my own cargo e-bike. I used steel, like most bicycles. For less than the cost of the special materials and supplies you're talking about, you can get a wire feed welder, some files, and steel tubing to make a bike that has the strengths and virtues we have come to expect. You can make a usable bike from bamboo or many other kinds of wood, but it won't have all the virtues that we take for granted with steel bikes. If bamboo or wood were an equally good material choice, wooden bikes would be common. The first bikes were made of wood over 200 years ago. We still have plenty of wood, but we don't still have plenty of wooden bikes.

I'm not saying don't do it. I'm saying that if you're using a material that has been eliminated after repeated use during a thorough 200-year development effort, know why you're choosing the rejected option.

Actually the bamboo option is way cheaper for me- for like 30€ I have 2 meters of guadua bamboo from a Dutch importer here in eastern Europe. In no way can the extra effort of working with either steel or aluminium, even without the costs of the equipment required match that. As for the resin, that's extremely helpful! Thanks!

Hi "Eastern Europe"... Canada here, eh?

You said "I've been riding/modifying/building electrical bicycles for the last 18 months now, and I'm ready for a new challenge."

Can suggest (Oh Oh...) you target "wealthy" buyers that want to buy at a profit for you? Like, this "old guy" lost any sense of balance - fell down a bunch of stairs... spent a week in a coma... so went tricycle... At first a "sit up"... and now a "recumbent".

Feel like making a `bent trike with assist?:

Welders can be rented or purchased used or home made.
Chalo already knows this but wooden bicycle are still made in 3rd world countries, I will indulge
Some are "scooter" style, like pre-teen style but this search reveals some with pedals.
https://duckduckgo.com/?q=Wooden+Bikes+Africa&t=ffnt&iar=images&iax=images&ia=images

http://nairobiwire.com/2014/08/wtf-introducing-african-wooden-bicycle.html

WTF! Introducing the African Wooden Bicycle

Who said Africans cannot be creative enough to invent stuff. This is a case of desperate measures in desperate times.

What happens when you’ve always wanted to own a bike but poverty is at an all time high you cannot afford one? Well…with all the time that comes with being unemployed you make one yourself..with wood. This man was spotted riding a well assembled wooden bicycle which proves that really, dreams are valid.

Click to expand...

OK what was my point
OK back on point

Actually the bamboo option is way cheaper for me- for like 30€ I have 2 meters of guadua bamboo from a Dutch importer here in eastern Europe. In no way can the extra effort of working with either steel or aluminium, even without the costs of the equipment required match that. As for the resin, that's extremely helpful! Thanks!

Click to expand...

Time savings you say

https://www.cleveland.com/tipoff/index.ssf/2018/05/his_work-of-art_handcrafted_wo.html

The former lawyer-turned-woodworker spent 150 hours crafting a wooden bicycle in his maker's space
..........................................
He had help from many others who come to his shop to learn his craft.

Click to expand...

Yup that is an artistic piece, lots of curves I can understand an argument of that vs a simple non artistic wooden bicycle.


https://www.instructables.com/id/How-I-built-a-walnut-triathlon-bicycle-frame/

Above is a picture from my first ride. I was so excited to finally get it on the road after 150+ hours of working in the shop on it.

Click to expand...

LockH said:

Hi "Eastern Europe"... Canada here, eh?

You said "I've been riding/modifying/building electrical bicycles for the last 18 months now, and I'm ready for a new challenge."

Can suggest (Oh Oh...) you target "wealthy" buyers that want to buy at a profit for you? Like, this "old guy" lost any sense of balance - fell down a bunch of stairs... spent a week in a coma... so went tricycle... At first a "sit up"... and now a "recumbent".

Feel like making a `bent trike with assist?:

Click to expand...

hey, sorry for not replying sooner. I had to abandon this plan temporarily because of studies and moving around and all that. Soon I'll be living on Malta. I like what you're suggesting here though, once I'm settled there we can talk business?