Introduction: How to Build a Bamboo Bicycle

I saw a picture of a bamboo bike and decided I had to have one. I found out that professionally built bamboo frames cost a few thousand dollars so I decided to build one myself.

I had a lot of fun and I hope that you can make one too by following these instructions.

The bike I made is a track bike for commuting to work. The bicycle was inspired by Craig Calfee who makes much nicer bamboo bikes. I really wanted something with a minimum of fancy technology and carbon fiber (although I sprang for the carbon fork). I used epoxy and hemp fibers on all the joints (no pun intended). The track bike also makes it easy in that it is a very simple bike - no gears, cable routings, rear brake or derailers.

Disclaimer: Death or serious injury can result from a bicycle frame failure. Using new and untested techniques is risky. Be smart.

Some links to check out before you get started:
Brano's instructable on carbon and bamboo bike building
Craig Calfee's bamboo bike project
Calfee bamboo bikes
Bike Forest BikeCAD
The forum for info on bamboo and heat treating it

The basic steps:
1. Figure out what type of bicycle you want
2. Get all of the parts and bamboo
3. Heat treat the bamboo
4. Tack it all together
6. Epoxy it all together
7. Build up bike
8. Ride off into sunset

Step 1: Pick the Bicycle Frame You Want to Build

If you are a real bike nerd you will love this step. You are now a frame designer and get to think about things like bottom bracket drop, chain stay length and head tube angle.

I suggest using an existing frame as a template (if you have one you really like).

If you feel ready to test your skills of an artist go to www.bikeforest.com and use the BIKECAD program. It is a free, online frame designing program.

Another good source of information is the Paterek Manual, which is actually for steel frames. Paterek goes into detail on how to size a frame based on body measurements and what each change in geometry means as far as road handling goes.

Once you have your geometry picked out draw your frame on a large piece of paper.

Step 2: Get Your Parts and Bamboo

There are some parts that you simply can not use bamboo for (maybe you can, but I didn't)
These are:
1. Dropouts
2. Bottom bracket shell
3. Head tube (I tried bamboo and it did not work - too wobbly)
4. Fork

I chopped the dropouts off an kids bmx which are very similar to track dropouts. The bottom bracket shell was cut out of a wrecked road bike frame. The fork I ended up getting was a carbon road fork from Nashbar. The pink one was just for sizing purposes.

The bamboo:
I had no idea what to get so I went to my local bamboo nursery and bought some hefty green pieces of bamboo. The size I chose was about the same diameter on say an aluminum bike.


Step 3: Heat Treat Bamboo

Sometimes being impatient pays off!

The bamboo I bought was green and freshly cut. I realized that it would have to be dry before I could use it but I wanted to use it right now! A brief interweb search tought me that bamboo can be heat treated. So I busted out the trusty old blowtorch and got to work on some test pieces.

Holy cow, heat treating bamboo is amazing. Steam and water literally spews out the ends. Sorry I don't have a picture of this (I was using both hands and recently broke up with my girlfriend so nobody was there to take pictures).

Practice on a few pieces first. The trick is to heat the bamboo evenly and slowly. The two step process worked best for me. The first step is to turn the green sections to a light brown. The second step is turn the light brown sections to a dark brown.

I also had a few dry pieces (already light brown) and only treated them once to get them to a dark brown color.

Another thing, I only did one section at a time (from one node to the next).

Heat treating turns relatively soft bamboo into a super hard material. It is incredible. My wood saw had no trouble cutting the green bamboo but I had to use a hacksaw to cut the treated bamboo.

Step 4: Tack Frame Togther

Now that you have heat treated the bamboo you need, cut, miter and tack the frame together.

You may choose to use a jig to hold everything in place. I did not use a jig so I am not going to go into that here. I don't know much about jigs so don't even ask.

I used the full size drawing and built directly off of that using spacers and standoffs to get everything in the right position.

Use a good half-round wood rasp to miter the joints.

Make sure that you use trigonometry to figure out the length of the chain stays and seat stays. What is drawn on the paper is a projected view.

Rough up the bamboo where the epoxy will go.

Rough up the metal too and stick it all together using 5 minute epoxy or your favorite glue.

Once it is all stuck together very gently put the wheels and fork in place and check alignment. If it looks good you are ready to move to move to the next step. If not

Note: The bamboo headset shown was not a good idea. I had to ream it out and insert a steel head tube because the headset cups did not seat properly in the bamboo and gave a scary wobble when turning corners! Start with a metal head tube and save yourself the hassle. The picture does show how rough your bamboo joint areas should be.

Step 5: Epoxy It All Together

Time to get dirty!

I used epoxy from fiberglass Hawaii called Aluzine (it is a 2 to 1 epoxy specially formulated for surfboards and has some UV inhibitors in it). Why? Because I had a lot of it left over from a repair to my windsurfer.

I used two different kinds of hemp fibers. I used raw hemp fibers (or semi-processed) and hemp twine (drawn out - semi-twisted, comes on a spool). The raw hemp seems much stronger so I used that as the bulk of the joint and then used the twine to tighten up the lashings.

Mask the frame off carefully. Prepare all the joint areas (clean and dirt free, heavily sanded or rasped for an extra-rough surface).

The process is pretty messy and requires a lot of patience and finesse. Wear gloves and start small - small batches of epoxy and small amounts of lashing. I mixed up a small pot of epoxy and then dipped my fibers in it. I then wrapped it on the joint and followed that with a dry piece of twine. There was enough epoxy on the raw fibers to completely wet out the twine. Practice and you will get it.

I got my hemp from www.downbound.com

Of course you can use kevlar, carbon fiber or fiberglass.


Step 6: Build Up Bike

Now you get to put in a bottom bracket and a head set. Stick on the cranks and chain, add the wheels and bar and the seat post.

Oh yeah, the seat post...

I thought my idea of having the seat post made out of bamboo was really cool. I spoke to my local bike guru who explained that the seat post is integral to the strength of the frame and advised that I insert a steel seat post into the bamboo tube. Luckily seat posts come in a wide range of widths. I folded a small piece of sandpaper in half (rough surfaces out) and wrapped that around the seat post to allow the bamboo to grip it. I then cut two slots in the bamboo to allow the seat binder to clamp the bamboo down on the seat post.

It all worked but then, crack! I guess the sandpaper was too much for the diameter of the bamboo and caused a small crack down the length of the seat post, almost all the way to the binding. I drilled a small hole to stop the crack spreading and now I will have to wrap the post in some hemp and epoxy.

I still rode it like this and it seemed ok but I am in the process of fixing it right now.

I also had to file down one of my joints at the dropouts to allow some clearance for the chain.

Step 7: Ride Off Into the Sunset

So how does it ride? Like a stealth bomber! The ride is smooth and silky and very quiet. I never realized how much noise a steel bike makes as you go over bumps and potholes. The bamboo bike is quiet.

Riding around on a bike you built yourself is thrilling.

I am still a little nervous about it breaking but every week I am getting less freaked out about riding it. I think the bike needs a name so if you have any suggestions...

The bike is actually not that light. It weighs about what my steel fixie weighed when built up - around 18 or 19 lbs. I will weigh it again and let you know.

Step 8: Sweet Pictures to Further Inspire You...

I took these of a Calfee bike parked outside the library - so awesome!

Comments

author
paolobertoncin (author)2015-05-16

great job

author
bpurcell2 (author)2015-01-01

Name 'Not just for smoking' as in , Hemp is;

author
davidbarcomb (author)2014-11-26

This looks great! I have to try this one

author
faceboogerz (author)2014-10-21

Where did you get all the dropouts joints from?cut out from an old bike or did you make them or did you order them?

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ayasbek (author)faceboogerz2014-10-22

Those dropouts were cut out of an old BMX. Now I get all my dropouts from these two:

Paragon Machine Works (www.paragonmachineworks.com)
or
Nova Cycle Supply (http://www.cycle-frames.com)

Hope this helps.

author
faceboogerz (author)ayasbek2014-10-22

Thanks yes your thread have been very helpful. ..and thanks for the two websites.

author
swimmer321 (author)2009-04-09

so after you wrap the joints of the bike in the hemp, can you sand it down to make it look nicer? the calfee bamboo bike joints are really really nice and clean-looking. How can i get that look?

author
chriscook42 (author)swimmer3212009-04-11

Thats what Im wondering. It is almost as if the hemp and stuff was melted into a single material. But you are right- it is a much more appealing look.

author

It's my understanding that, besides being very careful to wrap the joints as tightly/neatly as possible, Calfee overbuilds the joints, grinds them down, and does a final epoxy on the cleaned up surface. The overbuild is important, because it allows you to improve the aesthetic without reducing the strength of the joint. Just don't grind all the way through the overbuilt parts and it should be fine.

author
chriscook42 (author)chriscook422009-04-11

After further analysis it seems calfee probably did hemp and then fiberglass on top of it. The fiber glass could be sanded and I think that couldve made that look.

author
kklaw (author)chriscook422009-07-22

I would be careful with sanding through any of the hemp fibres, that is where the tensile strength of the joint comes from. The epoxy provides a matrix that helps to evenly distribute the forces throughout the joint but the fibres need to remain intact to provide any tensile strength. Chris's idea of a layer of fibreglass on top for cosmetics and some protection is often how fibreglass is applied. This is why carbon fibre must not be scratched, its structural integrity is severely compromised if any fibres are broken. This is a great project, I'm excited to try it with carbon.

author
peligro (author)swimmer3212009-05-31

I think the author intentionally had the joints look fibrous. If you soak the hemp cord in epoxy, once you put it all on the frame it should fit a lot smoother than in these pictures. And you will definitely be able to sand it down, it just won't be easy. Once the epoxy has cured the hemp/epoxy matrix acts like any laminate in that it is a relatively homogeneous material. It should be solid throughout.

author
CobyUnger made it! (author)2014-02-13

Fun project. Thanks for the help.

Bamboo_Bike.jpg
author
cameronbrown (author)2013-09-12

Here is my finished bike, with a step by step writeup
http://www.cameronbrown.ca/blog/2013/09/bamboo-bike-build-part-3-final-touches/

author
Kelly02 (author)2013-06-26

It must be lighter than usual bikes. Nice work.

author
dlu (author)2013-05-13

Hi~
I've a little Q:
How's ur bike now~?

author
ayasbek (author)dlu2013-05-14

I have stopped riding this one. My other bamboo bike has been sitting outside under a tarp for over a year now and still rides and feels great.

author
rjpeterson (author)2012-12-28

In response to:
"ayasbek (author) says: Jan 6, 2009. 4:10 PMReply
Wow! Looks good except for that one thing! I am so glad you got this far. Here is an idea - try get a different fork. Do you have a local frame builder you can speak to who could make you something? There are many old steel forks that have a good amount of rake/drag or whatever the offset from the headset is called. Another idea is to get a 650 wheel (sometimes called triathlon wheel). It is smaller and may allow you to ride your bike. It would also give you a super track star look but will lower your bottom bracket a bit. Either way be careful. If you really want to remove the hemp epoxy I think I would try a hacksaw or grinder. Chemicals seem like a bad idea."

Getting another fork with more rake is not a good idea. It may solve the problem of your wheel hitting the downtube, however the bike will have terrible steering characteristics. Bikes have a property called "trail". Trail is the distance behind the steering axis that the front wheel contacts the ground. Modern bikes with comfortable steering generally have a trail around 2-3 inches. In your picture above, the bike has close to zero trail. If you put a fork with more rake on that bike, you would end up with a non-existant or a negative trail. This would result in a bike that does not want to ride straight. In fact the fork will try to flip 180 degrees before it will go straight. Using a smaller front wheel would result in the same problem

author
Dandie (author)2010-08-15

I think It is not a very good idea to build a bike frame of bamboo because It’s impossible to assure strong and safe joint sticks, especially in the headset, one of the most stressed pieces. I have seen more than once headset breakages and I can assure that the consequences for the drivers have been horribly serious, they hit the pavement with their faces,……. noses, jawbones, teeth smashed. I think this is not a matter to play with.

author
syphek (author)Dandie2012-10-20

properly treated bamboo has a tensile strength equal to or greater than mild steel.

author
snotty (author)2011-05-21


Yeah, bamboo bikes are awesome. Make sure to build your lugs strong and use Tonkin or Iron bamboo or you may have problems.

DSCN0733.JPG
author
chuck190 (author)snotty2012-06-21

I plan to substitute top tube top tube of my steel bike with some bamboo of about 1" diameter (I could make it 1.25" if necessary). If I use iron bamboo of about 1"diameter, does anyone know if drilling out the center with, say, a 3/8" drill would weaken it too much? That would leave walls of about 5/16" or 8 to 9mm. I have read that walls of hollow bamboo should be a minimum of 3mm.

author
snotty (author)chuck1902012-06-22

Of course the only sure way to know is to test it.

But I've used bamboo with ~4mm sidewalls and it's been fine. Be gentle when you drill, if you push too hard it might splay the bamboo apart and crack. I've had trouble with this before.

Also be careful to let the drill find its own way down the hollow or you might drift too far to one side.

author
chuck190 (author)snotty2012-06-22

snotty - Your last sentence - drilling down the hollow - makes me think that maybe you don't know that iron bamboo is not hollow - it's the only species that's solid. I have already drilled hollow bamboo without a problem. Actually, when it split, I simply wrapped it with carbon tape. I used a pair in place of the steel chain stays. It has taken quite a pounding on some very rough roads without a problem.

But I would like to experiment with iron bamboo because I can make them into any diameter I need with a wood lathe. I'm thinking it would be OK to drill them to take weight off, but I was just wondering if anyone has had experience with this.

author
snotty (author)chuck1902012-06-23

Ah yes. For some reason I thought iron bamboo had a little hollow area. I must be thinking of some other type.

author
snotty (author)snotty2011-05-21

Yes, that's a bamboo wind turbine in behind me there: https://www.instructables.com/id/Wind-Turbine-Blades-from-Bamboo/

author
rudi.carfell (author)2010-08-31

Where have you bougth your hemps? And whats important to look at when I buy them?

author
davmaldo (author)rudi.carfell2012-05-07

Ebay! After some research, i believe you want the "bast" as it is the strongest part of the plant, i.e. search "hemp bast fiber" and you should get a few hits. I have had trouble sourcing hemp in its non twine form.

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LiquidLightning (author)2012-04-10

Uh.. Where did you get the hemp? Untangling hemp ropes? Cough cough.

author
snotty (author)2011-11-26

Any frame builders' supply has all sorts of head tubes. I chop mine out of dead bikes sometimes though.

author
foxes76133 (author)2011-11-15

Hey Ayasbek, I have some questions I'd like to ask about this project about "Heat Treating Bamboo".
I was wondering what tools you used for the project, and how you used them. I would like to experiment, but due to my finances, my experiments would also have to be useful, because I don't have enough money to buy bamboo in bulk amounts, and use some of it only to ruin it because of experimentation.
I've been trying to work on a project of my own as well, but not making a bamboo bike, it's actually to make shafts for Arrows for my bow. So I'd like to know more. Otherwise, I have to do a search and destroy all over Goggle just to find a dealer in my local area just for Heat Tempered Bamboo.

author
sephiroth67 (author)2011-10-09

Hope it's not TOO late, but B2 sounds like a fine name...fits your description of a stealth bomber, and you can just say it stands for bamboo =D

author
mykall (author)2011-10-07

hey there,
amazing job you did there, you have my greatest respect.
We were thinking of trying to build one in our bicycle cooperative, but the fella we are getting hemp from needs to know what kind of hemp fibre we need, how thin, and how clean, and also of course how much.
I was wondering if you could possibly help me with some advice?
how much did you use on one bicycle and what sort of hemp were you using?
look forward to your help

author
fgunnar (author)2011-09-16

Out of curiosity, how much does it weigh?

author
geekonabike (author)2011-08-19

The Woody

author
EngineerJakit (author)2011-08-13

So if you were to build something out of either green or heated bamboo, which would be the easier to work with? mainly with flexibility and hardness.

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mad doctor (author)2011-07-31

How did you get your bottom bracket shell out of the bike? Most of the bikes I have looked at have their bottom bracket shells welded on.

author
frisbeechamp1983 (author)2011-07-15

can this be used to make a hardtail mountain bike?

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willrandship (author)2011-03-04

Calc for blog cred...:P

Cool idea, but I'd be very afraid to ride it, myself. Even if a professional built it :P

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snotty (author)willrandship2011-05-21

Fear is scary stuff eh. Seriously though; I made a bamboo bike really badly and it broke in lots of places but it never fell apart. It just got wiggly.

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NetReaper (author)2011-04-05

Could you use a second metal piece under the seat that you put at the bottom? It seems like it's the same angles and it would be sturdier.

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Dylan Roberts (author)2010-09-03

The Bambicycle or The Bambike. Yeah...

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a918bmxr (author)2010-08-16

i have seen a frame break and the rider got a huge gash across his stomach from where the top and bottom tubes attached to the head tube... it wasn't pretty D-8

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Oxzane68 (author)2010-08-15

No offesnse, but I built one, and it shattered.

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SirRidesalot (author)2009-08-13

http://www.ridepanda.comYou should also check out what some guys from Colorado are doing at http://www.ridepanda.com. Their company, Panda Bicycles, looks like it's making some sweet bamboo bikes with steel lugs.

author
thepelton (author)SirRidesalot2010-08-12

Neat! I live in Colorado Springs! I may be up for a field trip. I wonder if there is any way to do the spokes in smaller bamboo?

author
thepelton (author)thepelton2010-08-14

Never mind! If you look at the calfeedesign.com website, you see that very thing done in Africa. It makes for a stronger back wheel that can carry larger loads than the standard wire spokes. 8>)

author
jentran (author)2010-07-14

For the headset, perhaps you could cut one so that there are nodes at either end to increase stiffness. There are more nodes located at the bottom of a bamboo culm than at the top. I'm not sure how thick the walls of the headset you tried was, that could help too. Some other people sprayed expanding form successfully to increase stiffness to the seat tube.

author
mmann1123 (author)2010-04-18

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.

IMG_3264.jpgbike5.jpgbike6.jpgbike2.jpg
author
Nkevin90 (author)2009-01-04

Okay, hopefully the last question; I really messed up on my headtube angle (but I couldn't help but laugh at it), so how would one go about taking all that crap off? I read up about sodium hydroxide or soaking stuff in acetone, but I'm not sure how great that either'd be for the bamboo itself. Oh right, and I used a steel tube by the way.

IMG_0786.jpg

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