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Discussion Forums => General Discussion => Topic started by: devnill on July 06, 2017, 09:19:58 pm
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are pretty cool, especially when they are made of bamboo. http://ghanabamboobikes.org/product/bike-frame/
(http://www.un.org/climatechange/wp-content/uploads/2014/08/bamboo-bikes.jpg)
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Looks like something one should try to make from PVC joints instead of dropping a whopping $250 on it. My initial thought would be to 3d print the joints, but I'm not sure if they'd be strong enough.
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I've been looking into bamboo a lot lately and 250 isn't actually that bad of a price. People seem to really like bamboo as an alternative to carbon fiber-- it's pretty light but extremely durable (although prone to splitting if not taken care of). A reasonable priced steel frame is about the same price and a carbon frame is easily a thousand dollars.
I don't think pvc is durable enough to work as a bike but i'd love a 3d printed bike. This bike is made from straight carbon tubing and 3d printed lugs:https://vimeo.com/78347167 (https://vimeo.com/78347167).
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I didn't know it was possible to 3d print titanium! that bike is 14500 euros. that is a lot.
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I'm just on the other side of the spectrum when it comes to bikes. I'm not into high quality bikes and traveling fast and all that fun stuff, despite living in a heavily bike-oriented community. I'm thinking for casual, low-income bikes.
I didn't know it was possible to 3d print titanium! that bike is 14500 euros. that is a lot.
A laser sintering printer is probably going to cost you quite a few nice bikes worth, let alone ordering the various powdered metals you're using with it.
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the "cool and easy" bamboo frame construction techniques i've seen involve using heavy duty shrink plastic that is heated with a blowtorch, it contracts and hardens. i don't know where you buy that stuff tho.
anyway 3d printers are PLA and ABS.. ABS can get pretty strong, I'm not sure how strong! but, you'd have to make a tapered joint for the bamboo to slide in. That's tricky. And you still have to secure it with a pin or a wedge or something. Or a clamping cutout?
PVC pipe is nowhere near strong enough.
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(http://www.motorcyclespecs.co.za/Gallery/Honda%20CG%20125%2095.jpg)
does this count
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the "cool and easy" bamboo frame construction techniques i've seen involve using heavy duty shrink plastic that is heated with a blowtorch, it contracts and hardens. i don't know where you buy that stuff tho.
anyway 3d printers are PLA and ABS.. ABS can get pretty strong, I'm not sure how strong! but, you'd have to make a tapered joint for the bamboo to slide in. That's tricky. And you still have to secure it with a pin or a wedge or something. Or a clamping cutout?
PVC pipe is nowhere near strong enough.
Most bamboo bikes I've seen use bamboo poles with carbon fiber or rope wrapped around the joints which is then covered in epoxy and sanded smooth. It seems like that would be easier than needing to make custom connectors that perfectly fit bamboo which often varies in size.
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the "cool and easy" bamboo frame construction techniques i've seen involve using heavy duty shrink plastic that is heated with a blowtorch, it contracts and hardens. i don't know where you buy that stuff tho.
anyway 3d printers are PLA and ABS.. ABS can get pretty strong, I'm not sure how strong! but, you'd have to make a tapered joint for the bamboo to slide in. That's tricky. And you still have to secure it with a pin or a wedge or something. Or a clamping cutout?
PVC pipe is nowhere near strong enough.
Most bamboo bikes I've seen use bamboo poles with carbon fiber or rope wrapped around the joints which is then covered in epoxy and sanded smooth. It seems like that would be easier than needing to make custom connectors that perfectly fit bamboo which often varies in size.
that's pretty cool. I didn't know you could weld wood like that.
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Looks like something one should try to make from PVC joints instead of dropping a whopping $250 on it. My initial thought would be to 3d print the joints, but I'm not sure if they'd be strong enough.
Honestly $250 is pretty cheap for a quality bike, most road bikes cost hundreds if not thousands of dollars. I like the idea of trying to make super affordable bikes, but have you looked at how much just the wheels / gears / breaks would cost individually?
As for building a bike out of PVC, I couldn't find many examples, but I did find these:
Side by side tandem bike made out of PVC:
(https://img.wonderhowto.com/img/88/20/63454366502173/0/pvc-2-person-bike.w654.jpg)
Super bulky PVC bike with a basket:
(http://media-cache-ec0.pinimg.com/736x/98/06/5d/98065de42918e217e254097995681f5b.jpg)
Have you ever used PVC for holding weight over a long period of time? It will inevitably bend unless you use super thick tubes.
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my bike cost $800 and it was done at cost for wholesale price (10% off catalog) it's also too small for me. unfortunately there's not a very big bike community here so no way to run into random people and swap. I do wonder if I could move all the parts to a homemade frame.
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regular PVC thickness is schedule forty (SCH40) and "really thick tubes" is schedule eighty (SCH80) just in case you want to buy some at a plumbing supply house. Low pressure pipe for sewer is huge and cheap but is also very thing (SCH10 or SCH20 i think) and breaks easily.
PVC gets pretty brittle when it's cold, even when it's not full of water. and floppy when it's warm.
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I can pick up a decent bike at my school's surplus store for less than $20.
Ya'll are bad at money.
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yardsale bikes are often really good deals, heavy fucking steel frame bikes from the 50s-80s that last forever and have bearings that can be repacked by hand. they weigh a ton, but last forever.
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yardsale bikes are often really good deals, heavy fucking steel frame bikes from the 50s-80s that last forever and have bearings that can be repacked by hand. they weigh a ton, but last forever.
Its really hit or miss. Road bikes started to get really big in the 70s and a lot of manufacturers started making cheap shit to fill a gap. The trick is to look for butted steel tubing: http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/ (http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/).
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yardsale bikes are often really good deals, heavy fucking steel frame bikes from the 50s-80s that last forever and have bearings that can be repacked by hand. they weigh a ton, but last forever.
Its really hit or miss. Road bikes started to get really big in the 70s and a lot of manufacturers started making cheap shit to fill a gap. The trick is to look for butted steel tubing: http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/ (http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/).
What's the difference between butted tubing and non-butted tubing? Why do you need to look for it?
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Instead of a tube which has a consistent thickness, butted tubes are cut in a way where the center is very thin and the edges are thicker. A good steel frame is actually a bit lighter and much more durable than aluminum.
yardsale bikes are often really good deals, heavy fucking steel frame bikes from the 50s-80s that last forever and have bearings that can be repacked by hand. they weigh a ton, but last forever.
Its really hit or miss. Road bikes started to get really big in the 70s and a lot of manufacturers started making cheap shit to fill a gap. The trick is to look for butted steel tubing: http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/ (http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/).
What's the difference between butted tubing and non-butted tubing? Why do you need to look for it?
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I always wondered how they made those weirdly shaped tubes of varying thickness. Now I know!
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Hey lads, building my own bike out of steel tubing has been a goal of mine for many years. If any of you have any experience or advice I am down to listen.
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Hey lads, building my own bike out of steel tubing has been a goal of mine for many years. If any of you have any experience or advice I am down to listen.
i am so curious why you want to do this! please answer these questions, should only take a moment
- why do you want to build your own frame?
- why out of steel?
- is it a conventional two wheel or something more?
- do you have any steel fab experience?
- do you have any bike assembling/building experience?
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Hey lads, building my own bike out of steel tubing has been a goal of mine for many years. If any of you have any experience or advice I am down to listen.
i am so curious why you want to do this! please answer these questions, should only take a moment
- why do you want to build your own frame?
- why out of steel?
- is it a conventional two wheel or something more?
- do you have any steel fab experience?
- do you have any bike assembling/building experience?
I am hoping to start building my own frames because I hope to start creating my own custom bicycles. I am hoping to eventually gain the skill to deviate from the typical bike frame design and build something more exotic, such as a velomobile. Rachel has also given me pictures of exotic pedal powered vehicles seen at Burning Man. There are also facebook pages like freakbikers Unite, which show people making highly exotic pedal powered creations. I have found these pages and resources to be extremely inspiring. I hope to create similar vehicles in the future, but I have been told I need experience building more conventional bikes first.
https://www.facebook.com/groups/freakbikersunite/
https://www.facebook.com/groups/115024628543289
As for steel fab experience, I do have some limited experience with TIG welding steel, but I am hoping to get more practice with the thin wall 4130 chromaly tubing, which is what I have been told most bikes are made out of. As for bike assembling experience, I recently built a bike from spare parts at a bike store. I also recently attended a bike frame building course held in Colorado by a lad by the name of Walt Wehner. I am very serious about making this happen because cycling incorporates a mix of mechanical aptitude and physical exercise. I am also hoping to do this to gain metaphorical "brownie points" with my friends who are also into cycling, some of which have expressed a desire to make custom tandem bicycles. I would post pictures but I am not sure how the post picture and post video options work on these forums. Anyway, I will also be the first to admit that I still have a long ways to go, but I hope through determination, grit and asking for help I will eventually be able to make custom bicycles.
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Also, steel chromaly tubing is also relatively easy to source. More exotic materials like aluminum, titanium, carbon fiber, etc are very expensive and typically not recommended by a beginner, though learning how to make custom bikes from such materials is possible.
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Does this answer your questions Mr.Truck?
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thank you for answering my questions!
you're not the only one who has difficulty with the images/video thing - there's an upload page somewhere where you can put pics and vids up to be hosted locally - I think its https://wiki.wetfish.net/uploader
out of all the people I've ever heard "I wanna build bikes" out of, you are easily the most prepared and most realistic. It's great you have steel fab experience and knowledge about sourcing! Esp TIG welding!
A long time ago I wanted to build my own recliner for a while but I realized i needed a LOT of skills and practice that I wasn't willing to invest for just one bike!
I don't think there's anything I can do to help you - I know just enough to know what I don't know, and my role in the past has been: buzzkill! IE informing people of the harsh realities and hours needed investing in skills to do what they imagine. This is not really creative or helpful of me.
One tip I can give; i used to volunteer at a bike co-op and we had piles of frames that just weren't worth investing in. I wanted to make art or machines out of em, but at the time I didn't have space or money. If you have a co-op near you, they probably have a similar pile. Can be great for bearings, cranks, etc
Do you have
- a weld fab table (to keep your fabs in square)
- a bender (for precise fab of a specific design)
- a method or jig to cope round tube
of course none of these are NECESSARY and can be improvised with a workbench, a vice, and some hand made tools and a LOT of elbow grease - but I find that people tend to burn out on the elbow grease and exhaust their time before they can get to the creativity
if you're planning on dedicating all your hobby time to it, or actually gonna make money off it - thats probably the only time its sensible to invest in that equipment.
I would LOVE to see your forays into this, I hope to see more of your posts in the future! I'm so excited for you!
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Thanks for the encouragement. I feel I have made some progress, but I still have a ways to go. I have managed to figure out how to miter tubes with a lathe and Milwaukee hole saw.
https://drive.google.com/file/d/1PUhCW4N02cE_jm5dYXO97crU7M-y82zw/view?usp=sharing
I have also managed to create a very simple jig using aluminum extrusion and welding magnets.
https://wiki.wetfish.net/upload/cbaebbed-f7d3-cdf3-4050-ab9c72319b4f.jpeg
I also do have access to both TIG and MIG welding machines through the local makerspace, as well as many people with prior welding experience. I will admit though that finding the correct mandrel for bending tubes will be difficult, but can be fabricated out of wood if necessary. Overall, I do have much of what I need to manufacture a bike, with the largest obstacles right now being development of my welding skills and finding time for this endeavor. Time is an issue being that I am doing this as a hobby/side hustle. I am hoping to do this half because I think bikes are cool and half because I am desperate to impress my bicycle oriented friends.
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Also, here is a picture of my latest TIG welding practice for coped joints. The impression I got from my friends is that this is an OK job, and more practice is required before I attempt to build a bike.
https://wiki.wetfish.net/upload/33c5f6b3-f99a-b4b8-fed7-9771efc6aef3.jpeg