Building a Bamboo Bike

[bikebuilder]

Hey,

Some of the projects you guys have been working on are absolutely beautiful.

I might tackle one of these myself, but I need to solve a few things before trying it.

1. I can't figure out for the life of me how in the world the seat tube works. Is there a metal insert in there? Did you ream out the bamboo before putting the insert in there? Or did you just ream out the bamboo and use it without an insert? Also, how did you ream out the bamboo?

2. Does the resin stick to the metal bits? How did you guys do that? Just majorly rough it up?


Thanks,

bikebuilder

[Juneau Bamboo]

Hello all- here in Juneau Alaska we have put together a group to while away the shortening winter nights. We expect to pool together resources to build some bamboo bikes!
So far we have done all the research I'm sure you all have, found the instructables, etc. We have a bucket of epoxy resin and tools, etc.
Bamboo Hardwoods is supplying us with some Tam Vong bamboo- I highly recommend them as their service has been great and they practice sustainable harvesting.
I have a question for any and all who know about this- what is your opinion on using Tam Vong? It is a structural type used throughout SE Asia. It is almost solid (little to no voids) and we were thinking of drilling it out to size. Kind of like milling really.
I will keep you all informed as we make progress but so far we are excited!
Check us out!

[bikeninja]

Hey ya'll great posts thus far, very helpful. I am currently in the process of building my first bamboo frame, so far it's been alot of fun. I am using Black bamboo for the top tube, seat tube and Tonkin for the dropouts. Does anyone know how to achieve the asthetic quality of joint that Calfee is producing? His are smooth and do not really show the hemp fibers. Any ideas?

[bikeninja]

I am also curious of the diameters of the bamboo you guys are using for the top tube and seat tube?

[danimal]

It appears that the joints are way over-wrapped and then sanded to shape. I build surfboards and so have a fair bit of experience with composites and epoxy resin. I would pre-tack one end of a length of raw hemp fiber w/ two minute epoxy (that can be obtained at any home improvement store) at the joint. Then wet out the rest of the fiber making sure to get full saturation. I would use resin with a forty-five minute pot life. Once you start your wrap, that initial tack should enable you to pull a good tight wrap which is crucial right up next to the frame members to minimize voids. You are going to want as much fiber in there as possible. Then just build up that joint, give it at least twenty-four hours to cure and sand away, being careful not to remove too much material. One more thing about epoxy resin for anybody wanting to do this, is that it MUST be thoroughly mixed. The resin will not cure on its own without the hardener. You could end up with gooey pockets throughout the joint. A good rule of thumb is three minutes of continual, vigorous mixing with a wisk. I hope this was helpful. Good luck!

[bikelife]

Originally Posted by bikeninja

Hey ya'll great posts thus far, very helpful. I am currently in the process of building my first bamboo frame, so far it's been alot of fun. I am using Black bamboo for the top tube, seat tube and Tonkin for the dropouts. Does anyone know how to achieve the asthetic quality of joint that Calfee is producing? His are smooth and do not really show the hemp fibers. Any ideas?

Calfee are sanded and sanded till shape is formed.
you could to a outside mold to make some shape to it.
of just wrap in electrical tape and that would get it close.

[mmann1123]

Hey everyone I have found the large majority of 'how to' sites lacking in specificity. I am putting together a blog with a lot more detail and experiments together come check it out at http://bamboobike.wordpress.com/.

There are a lot of pictures and good details on how to choose materials, how to miter better, even how to make a hemp fiber head tube etc. Hope it is helpful.

[lampcycle]

I'm new to this forum, and in the process of building a bamboo bike, so I was very pleased to find this thread! Thanks to everyone that has shared their experiences.

I have done a few test pulls of epoxy/carbon fiber joints, using both the tape and vacuum bag method. The carbon fiber creates such an itchy mess however, that I am planning to switch to either hemp or bamboo fibers. Currently I am trying to figure out how to size and source the fibers. I did one test joint using hemp twine, but it seemed really dry when I sanded it, making me think it did not wet out well. I will post some images soon -

mmann1123 - I just skimmed your blog site and it looks awesome. If you are interested, I would be willing to contribute my images and experiences as I move further down this road.

Leo - Lampcycle

[ericstevens73]

http://www.instructables.com/id/Bamboo-Bike-2/

http://www.instructables.com/id/How-...cycle-or-bike/

My first 2 bikes...

[mmann1123]

Thanks that would be great. Just shoot me a response through my bamboobike.wordpress.com and we can put up your pictures and comments

Originally Posted by lampcycle

I'm new to this forum, and in the process of building a bamboo bike, so I was very pleased to find this thread! Thanks to everyone that has shared their experiences.

I have done a few test pulls of epoxy/carbon fiber joints, using both the tape and vacuum bag method. The carbon fiber creates such an itchy mess however, that I am planning to switch to either hemp or bamboo fibers. Currently I am trying to figure out how to size and source the fibers. I did one test joint using hemp twine, but it seemed really dry when I sanded it, making me think it did not wet out well. I will post some images soon -

mmann1123 - I just skimmed your blog site and it looks awesome. If you are interested, I would be willing to contribute my images and experiences as I move further down this road.

Leo - Lampcycle

[kennstokes]

One of the challenges in working with bamboo (and I work with it daily) is splitting and cracking. First you need to start with mature bamboo; too often bamboo is sold that is immature and just not ready to even harvest.

Next consider (after curing) burnishing your bamboo. This removes moisture and tempers the bamboo with a bonus of giving the finish a beautiful ebony finish. It takes a little more work and will involve the purchase of a small butane torch and butane, but the end results will save you money in not having to replace bamboo the splits and cracks as it cures.

If you have having trouble finding the bamboo you need let me know.

Kenn

[Tanzania Bikes]

@ bikebuilder

1. I can't figure out for the life of me how in the world the seat tube works. Is there a metal insert in there? Did you ream out the bamboo before putting the insert in there? Or did you just ream out the bamboo and use it without an insert? Also, how did you ream out the bamboo?

2. Does the resin stick to the metal bits? How did you guys do that? Just majorly rough it up?

Some people use a metal insert inside the seat tube but I figured that it is also possible without.
At my bicycle the bamboo just had the perfect inner diameter so that I just had to brake one wall inside then I VERY carefully used sandpaper.
At first the seatpost would still slip inside the wood. There was not enough friction so I added some beewax on the seatpost and inside of the bamboo. That gave enough friction that I could sit on it.

And the resin sticks well on the metalbits. Of course it helps to use sandpaper or even a grinder.


To all of us: Don't you think it would be helpful to make a bamboobike wiki?
Some overview where you can find every information you need to build a bike!?

[mmann1123]

Originally Posted by Tanzania Bikes

@ bikebuilder



Some people use a metal insert inside the seat tube but I figured that it is also possible without.
At my bicycle the bamboo just had the perfect inner diameter so that I just had to brake one wall inside then I VERY carefully used sandpaper.
At first the seatpost would still slip inside the wood. There was not enough friction so I added some beewax on the seatpost and inside of the bamboo. That gave enough friction that I could sit on it.

And the resin sticks well on the metalbits. Of course it helps to use sandpaper or even a grinder.


To all of us: Don't you think it would be helpful to make a bamboobike wiki?
Some overview where you can find every information you need to build a bike!?

Although some people go without a metal seat tube insert I WOULD NOT RECOMMEND IT. The seat tube takes the brunt of your weight and torque, it needs to be one of the strongest poles in the bike. I highly recommend reaming out the seat tube a bit to insert a small portion of a steel seat tube. This offers more rigidity and allows you to clamp down on the seat tube without cracking anything. One bad crack will ruin your bike.

I have some very clear directions on how to sink a seat tube here:
http://bamboobike.wordpress.com/sinking-the-seat/

I also give show you where to get the proper diameter/type tubes here:
http://bamboobike.wordpress.com/choosing-metal-bits/

[mmann1123]

Originally Posted by lampcycle

I'm new to this forum, and in the process of building a bamboo bike, so I was very pleased to find this thread! Thanks to everyone that has shared their experiences.

I have done a few test pulls of epoxy/carbon fiber joints, using both the tape and vacuum bag method. The carbon fiber creates such an itchy mess however, that I am planning to switch to either hemp or bamboo fibers. Currently I am trying to figure out how to size and source the fibers. I did one test joint using hemp twine, but it seemed really dry when I sanded it, making me think it did not wet out well. I will post some images soon -

mmann1123 - I just skimmed your blog site and it looks awesome. If you are interested, I would be willing to contribute my images and experiences as I move further down this road.

Leo - Lampcycle

Absolutely contribute to the site. Any experiments or techniques are welcome.