Framebuilders - Bambooo!

Alright after going through the previous threads I decided to make my own and maybe try to consolidate a the information into one place.

Just to preface, I'm not an experienced cyclist let alone frame builder. So anything that I may suggest is just my opinion. This thread is also to document my build process so others can use it for reference.

My goal is to build a bamboo frame and I think I've got a pretty good understanding but there are some parts that I could use some clarification. Firstly the seat post, is it just slid straight into the bamboo with the locking collar at the top?

Also for the bottom bracket is it best to get a lugless and weld or attach some mounts for the bamboo to slide onto just for increased rigidity. If this is the case what would the best method for this be? Or would it be easier to just chop an old frame up?

Also for the rear triangle are there any good methods for alignment? I plan to build a cheap jig (maybe something like this http://www.instructables.com/id/Almost-jigless-bicycle-frame-building/ ).

Resources: (will be updated as the thread progresses)
http://www.instructables.com/id/Bamboo-Bike-Frame/
http://www.instructables.com/id/How-to-Build-a-Bamboo-Bicycle/
http://www.instructables.com/id/How-to-build-a-Bamboo-Bicycle-or-bike/
http://www.instructables.com/id/How-I-built-a-carbon-bike-frame-at-home-and-a-bam/
http://www.bikeforums.net/showthread.php?t=376129&highlight=bamboo

Alright I'm going to reserve this first post and update it with progress, tests, and results.


From Plant to product:
http://img.photobucket.com/albums/v317/the-jackal/1019091222a.jpg
http://img.photobucket.com/albums/v317/the-jackal/1019091222b.jpg
http://img.photobucket.com/albums/v317/the-jackal/1021091109.jpg
http://img.photobucket.com/albums/v317/the-jackal/1021091108.jpg
http://img.photobucket.com/albums/v317/the-jackal/downsized_1021091443.jpg

These pieces were just practice so I could get used to the heat treating process.
At my school I have access to a large machine (the name slips my mind at the moment) that can apply a lot of force but measure it very accurately. I plan on using several methods of heat treating and messing with the bamboo to find the ideal methods. I'll try adding some foam as BME suggests and test whether it makes a difference and if so by how much. I'll try heating, sanding, reheating. Just heating, then letting it dry out in an oven and then hitting it with the flame.

Also to heat treat it all I did was take a plumbers torch with mapp gas and go back and forth over the bamboo until it started to darken. After the testing I'll figure out which method works best and try and repeat the results.

There is some question over whether heat treating is actually anything more than a method to remove excess moisture. Invariably the material will return to the ambient level, but heat treating either removes excess moisture above ambient, from growth or storage, or it lowers the moisture below ambient to a more favourable range, depending on the ambient range. Flaming by itself is just rough and ready heating. People like it the look also.

I make bamboo rods but haven't made a bike. If it was me, I would get an aluminum BB and use carbon fiber to make the connections, or glass. Not sure this is an app where the benefits of carbon are required, at least for initial experiments. Carbon is always lighter, but since it isn't the stuff the bike is to be built of, it may not be necesarry. Some of that Rutan tow that Aircraft spruce sells might come in handy.

Contour I applaud your craziness. I love this thing you are trying. I've made a few longbows out of Tonkin Cane which is a type of bamboo. In my work, however, it was cut into strips and then I made a press and used epoxy to bind everything together. Using the whole plant as a "tube" may require you bind the ends of the bamboo (like end of seat post) with some kind of thread to keep the bamboo from splitting. It can be done in a decorative way. I'll keep an eye on this thread. Can't wait to see what happens. Good luck.

There is some question over whether heat treating is actually anything more than a method to remove excess moisture. Invariably the material will return to the ambient level, but heat treating either removes excess moisture above ambient, from growth or storage, or it lowers the moisture below ambient to a more favourable range, depending on the ambient range. Flaming by itself is just rough and ready heating. People like it the look also.

I make bamboo rods but haven't made a bike. If it was me, I would get an aluminum BB and use carbon fiber to make the connections, or glass. Not sure this is an app where the benefits of carbon are required, at least for initial experiments. Carbon is always lighter, but since it isn't the stuff the bike is to be built of, it may not be necesarry. Some of that Rutan tow that Aircraft spruce sells might come in handy.

The TOW is much easier to deal with than cloth in my experience.
The heat treating is to remove excess moisture and to help prevent splitting as I understand.
I smoked my bamboo, supposedly it helps keep fungus, mold, and bugs down.

With the bottom bracket you can get away with just scoring the surface so the glue/resin has something to grab ahold of.

Wrapping the chain stays in carbon helps to stiffen the frame.

Thanks for the suggestions an comments everybody!

Allen, how has the smoking worked out for you? Did you notice an improvement in protection from the treated and untreated pieces? I've been looking around for treatments for bamboo to ensure it's longevity but I have yet to see anything consistent. Some sources say let it soak in water for three months, others say soaking in boron solution, along with other methods. I'm curious as to how the compare with each other and will try to test different methods. However these are long term effects so it's hard to test for them.

Also have you had any issues with crank arm clearance with the bamboo chain stays?

Also, if anyone has any resources on curing carbon fiber (clothe or tow). Also what kind of epoxies are used with the hemp and sisal (having trouble finding a source for this, if anyone has one let me know) fibers. Does the curing matter based on the material, epoxy, or is it a combination?

Contour you refer to curing carbon fiber. In all my years of building race kayaks (that's what I did for work) with carbon fiber cloth, I never heard of a person paying attention to moisture content. The stuff comes in a roll from the factory. It takes on whatever the relative humidity of the work shop is (in time). I would not worry about curing. Unless you are talking about the curing of the epoxy used to bind the fibers. Then you should just read the manufacturers literature. For any natural fiber like wood, sisal, hemp, you can not go far wrong with WEST SYSTEMS epoxy. It's formulated for wood boats. There are other equally good products available however. In time you will find there is very little magic in working with composites, natural or man made.

Doesn't the carbon need certain tempatures to cure, that was one thing I was concerned about, or is it just all resin's/epoxies in general? And is there any specific West Systems epoxy that you would recommend?

No on the carbon fiber. It is inert. Use it like it were wood or fiberglass. The only thing that is important is the kind of binder (resin) you use. It must me compatible with the carbon format (linear or fabric) and it should be allowed to set (cure) at the manufacturer's recommended temperature. Some do need an oven and higher temperatures. But most modern epoxies set at room temperature just fine. The list of agents is too long for me to type here. West Systems will work with all carbon products even though it's most often used in wood work and wooden boats.

It's been a few years since I used WEST SYSTEMS, but when I did, they only had one base epoxy with several different catalysts for different ambient temperature ranges. One was for temps around 75 F, another was called "Tropical" and it was a slower hardening catalyst for use in the tropics, or for a longer pot time. I think there was one other but I can't remember its purpose. A guy could do all that was needed to be done with the standard hardner and the slower "Tropical".

It's always a good idea when playing with resins for the first time to make up a test batch and get a feel for how it "sets up". Spread some on a little bit of carbon fiber or glass cloth. Glue some pieces of wood together with it. Thicken some with glass beads or micro-fibers. Get a feel for it. Making things out of wood and fiberglass is addictive.

P.S. Standard WEST SYSTEMS hardener has about a ten minute pot life. Less if it is above 80 F. Tropical extends the pot life to about 2 hours at 80 F. Both hardners set up faster as the temp goes up. At 95 F and above I used to leave the shop and go drink beer instead. Everything happens too fast.

May be a silly question but what is the difference in pot life and working time? Also just another general question, do you let the previous layer completely cure then add the next layer? Or is the second layer applied almost immediately after. For the linear how exactly would it work, just don't overlap on the same layer (if it needs to cure before applying the next layer)? Also for vacuum bagging is the primary purpose to get out the excess resin for weight purposes or strength?

Pot time, working time, pretty much the same thing. Remember mixed epoxy in a container will get hot fast. That same epoxy spread out cannot develop heat as fast. So to extend pot or working time, spread the stuff on a surface and take it from there like a painter uses a palette. Make a practice batch and pour some in a dixie cup. Spread the rest on a paper pie plate. See how they cure at different rates. The cup will even start to smoke. (It's not real smoke) When I said 10 minute pot life, I meant the lump of epoxy in the dixie cup. That's the "worse case" scenerio. Same is true for tropical hardener. Maybe 2 hours in the dixie cup and could be 4-8 hours spread out.

You can add layers of glass or CF as soon as the first layer is set up. No need to sand between layers. This will only result in very clogged sandpaper as the epoxy is firm but not really stone-like. No problem with adhesion between layers. But do not go more than 48 hours between layers with WEST SYSTEMS or you will have to first wash the surface and then sand. The reason being the curing epoxy releases a chemical called "amines". I could have the spelling wrong and really don't know what the hell amines are. All I know is that they form a water-soluable top layer that is greasy to the touch. Almost like someone rubbed baby oil on the surface. And it has a strong chemical smell. This greasy layer will mess up further layers if you do not remove it with soapy water and then roughen the surface with course sandpaper. This should never be a problem if you simply do all your layup work in rapid succession.

Linear stands can be arrainged at your whim. It's the epoxy and how long you take between applications as mentioned above that is important. You always want previous work to stick to later work. If you have to wait long periods between epoxy application just wash the old work and sand. It's those damn amines that slowly work out of the epoxy you have to be aware of. If the thing you are making is done all in one shot, as in vaccum bagging, amines are a moot point. (unless you plan to paint the surface - then treat painting like another layer of epoxy: wait 3 days, wash, sand, paint)

You are exactly correct about vaccum bagging. It's the best way to control the exact amount of resin going into a known area of composite material like glass or CF. A good layup man working by hand can equal the quality of a vaccum bagged product. But there are damn few good layup men around. (Now for some shameless self-promotion) I was the first person to use vaccum bagging in commercial kayak construction in the US and probably the world. That was in 1978 about 5 years ahead of most other makers. I went to VBagging because I could not find workers who could do hand layup work of suitable quality. At first I held my nose at the notion, but in time came to realize what a good thing it is. The technique was taught to me by an engineer I hired from the aircraft industry. I did not invent VBagging by any means.

Hope this in some way helps.

That is very helpful. Would it be worth it, at least in your experience to build a small vacuum bagger that could be fit around the joints?

Also for linear strands is it best to alternate the directions layer by layer, or at least to have the fibers going both ways?

For what you are doing bagging would serve no real purpose. The little joints are easy to fuss with and not over-epoxy. Bagging works best with larger products where total finished weight is important. If you use too much epoxy on one joint it means (maybe) a quarter ounce. No big deal.

It's hard for me to advise how you should set stands of CF without seeing the application. I suggest you make a couple of test joints out of scrap bamboo and test them yourself. That is half the fun of making anything anyway. Do remember that carbon strands (unlike cloth) do not bend, they break all at once. This can be very exciting should it happen on the prototype at 30 mph. Make test pieces first.

Truth be told, 98% of my CF work involved fabric in boat hulls. The only strand work I did was in wing paddles. It was simple work and I can't really say I learned much. I'm sure there are guys on the forum who have done more with carbon in linear form than me. There might even be good information at the library or on the internet.

Do not listen to people who say what you are doing will not work. The world needs nuts like you. Push on, and if it doesn't work out, no big deal. As a kid I started to make a submarine out of oil drums. The cops stopped me at the launch site. I still regret not having completed the project. Carry on, and down periscope!

I use West Systems. One squirt from jar A one from jar B. Can't beat it.

I got my carbon through Aircraft Spruce and I don't remember where I bought my hemp fiber--I just searched for "hemp fiber" and picked one.

The bamboo I bought was already dried, I'm sorry but I don't know if the smoking process did anything but change the color a bit and made the wood smell good.
When I bought my wood I bought two different verities of bamboo, Black and Moso.
Some of the black bamboo split during the smoking process. The rest has been stable for several years now.
I did not smoke the Moso and it split (with sudden and loud pops) over the next two years just sitting in my shop.
Of the 80 feet of Moso I originally purchased, I have maybe 12 feet of usable wood. I won't buy moso again.

Too bad you're on the opposite coast from the Bamboo Bike Studio. They have a 2-day course that teaches you the basics of building bamboo bikes. (They are doing good things in conjunction with Columbia University's Bamboo Bike Project--attempting to help establish factories to build bamboo bikes in a number of third world countries.) Since you're a student, maybe if you contact them, the Bamboo Bike Studio can give you some pointers via e-mail. Here's a link to their web page, which has contact info. http://bamboobikestudio.com/go/home Good luck, your project sounds interesting. This is a thread I'll keep track of.

Too bad you're on the opposite coast from the Bamboo Bike Studio. They have a 2-day course that teaches you the basics of building bamboo bikes. (They are doing good things in conjunction with Columbia University's Bamboo Bike Project--attempting to help establish factories to build bamboo bikes in a number of third world countries.) Since you're a student, maybe if you contact them, the Bamboo Bike Studio can give you some pointers via e-mail. Here's a link to their web page, which has contact info. http://bamboobikestudio.com/go/home Good luck, your project sounds interesting. This is a thread I'll keep track of.

I had no idea that this had been done. I'll have to Google Bamboo Bike Studio. People who think along such odd lines are the best.

i built three frames out of bamboo back in 2007
one broke due to undetected worm infestation
the other two are doing fine!
i had a couple threads about them and other's 'boo bikes here

ChiapasFixed: Coolest bike photos I've ever seen. Do the bikes ride soft? There must be some flex.

surprisingly little flex, similar to a steel frame but with the vibration dampening of a carbon one.
i understand the rear triangle can be stiffened further by wrapping the chainstays in carbon cloth.
I have not found this necessary, but I dont seriously race. the fixie is plenty fast, though. it is modeled after an Eddy Merckx corsa extra.

Also check out Sol Cycles in Princeton, NJ...

http://www.solcycles.com

Also check out Sol Cycles in Princeton, NJ...

http://www.solcycles.com

Thanks for the link. If someone had told me you could make a working bike out of bamboo and it would hold together over the first lumpy road, I would not have believed it. Untill I joined this forum and found this link, I had never heard of bikes made out of any kind of wood let alone a grass. (bamboo)

Here's another one...Calfee Design, a longtime top maker of carbon bikes (I believe they made Greg Lemond's Team Z bikes), offers a bamboo bike. They also have some kind of work they are supporting in Africa to make cheaper bamboo bikes:

http://www.calfeedesign.com/

As far as other wood-frame bikes, here's one I found:

http://www.renovobikes.com/

Frames look absolutely beautiful, although they are not as "green" as bamboo. I don't think they are as strong/light as bamboo either...

Calfee got the bamboo thing going again (it's been around as a frame material since the beginning of cycling).

Calfee inspired Brano Meres, and he built a bamboo mountain bike. Brano's website has inspired a lot of hobbyist builders.

http://www.bmeres.com/bambooframe.htm

Funny how so many folks discover bamboo to use for bike frame building. I had the idea a while back while bike riding in Asia, only to find out they've been around over a hundred years.

Why haven't they caught on in the industry?

I'm hoping now is the time. We've been working toward building a business to bring respectable jobs and skills to folks in the developing areas of south east Asia.

bamboobikemaker...that is a seriously beautiful bike!

Funny how so many folks discover bamboo to use for bike frame building. I had the idea a while back while bike riding in Asia, only to find out they've been around over a hundred years.

Why haven't they caught on in the industry?


Is it feasible to mass produce bamboo bikes? If you have a bamboo farm, you can choose the stalks you want, but how well can you control the width and thickness? Using metal that you can melt, you can shape your materials to your needs with very little waste. So maybe that's why there isn't a big bamboo bike industry.

What kind of durability can you expect from a bamboo frame? I picture the joints working and grinding themselves to sawdust. Or are they captured in such a way they cannot work (move).

I have spent a good bit of time in the South Pacific and do not remember ever seeing or hearing about a bamboo bike. Of course I was not looking for one as I did not know they existed. Venture to guess what kind of useage is prevalent in certain Asian nations?

The pictures presented on this forum do not betray anything really different to the casual eye. I can see how I could have missed such bikes if I did not have my hands on one.

My understanding is that most of these bamboo frames use some kind of carbon fiber wrap to secure the joints.

My understanding is that most of these bamboo frames use some kind of carbon fiber wrap to secure the joints.

The lugs are built up on the frame out of carbon or hemp fiber usually.

Durability is superb for a well engineered frame (including the species, age, and treatment)! Each frame is hand built, so the automated mass production is what I believe keeps the big boys from venturing here. A good set of calipers can tell you where to cut for the diameter your looking for. However, the culms are not always round, you just have to adapt and use this to your advantage.

you can see a youtube of my project by searching for "bamboo bike by phil webb".

Hey guys, I haven't given up on this project and plan to finish during my break between semesters.

The things I am currently thinking and wondering about are, which hemp fiber, raw, sliver, or a twine? Or should I just go carbon, and if so I have seen conflicting information. Some say to use tow and to just wrap, others say that a weave would be much stronger. I have also been thinking about taking a bike and just chopping it and slipping the bamboo over so I don't have to worry about alignment issues the first time around.

The raw hemp fiber will work the same as the finer fiber. I am now under the opinion that twine may leave air pockets or pockets of resin void of fibers. I think you can make a stronger product with fiber (make test pieces and destroy them to draw your own conclusions).

I personally find TOW line is easier to work with than cloth. I am unsure the differences in strength.

Sand the enamel skin off of the bamboo wherever you want the resin to adhere.
Cutting through the skin before you cut the tube will lessen the chance of the skin splitting.
Wrapping the cut in blue painter's tape before cutting will also help.

Bamboo is not perfectly straight. I think you will still have alignment issues if you cut up an old frame and try to make an internally lugged frame.

Use off the shelf (Nova, Henry James, Paragon Machine Works, etc.) metal parts (head tube, bottom bracket, dropouts) and mount them to your jig so they are properly aligned. Fit the bamboo between them.

Miter the bamboo the same as you would using metal tubes, then tweak the fit by sanding the miters so the bamboo lines up as you want.

Well I'm trying to get away with out a jig but do you think the scratch build is better (a more precise final product)?

I would have thought that the longitudinal fibre alignment of the bamboo tubes would compromise their torsional rigidity .

This is supported by data showing that bamboo has a typical ratio of EI / GJ greater than 8 where isotropic materials with moderate Poisson's ratios (eg metals) give values around 1.3. Since EI / GJ describes the ratio of bending stiffness to twisting stiffness, this says that the bamboo has about 16% of the torsional rigidity of an equally laterally stiff metal tube. Since the bamboo tube will have lateral stiffness less than or equal to that of a metal tube of the same diameter and weight, this gives it at best 1/6th of the torsional rigidity.

It is well known that torsional rigidity of frame tubes is extremely important for handling - you don't want the down tube and top tube twisting enough to pull the head tube out of alignment with the rest of the frame.

Am I missing something or is this another case of something which looks like a good idea but really isn't?

Mark Kelly, you obviously know a heck of a lot about materials than most of us do. I relish your question and hope for an answer from somewhere.

Well I'm trying to get away with out a jig but do you think the scratch build is better (a more precise final product)?

I'm building off of a level table, not unlike ****'s setup here: http://ottobelden.blogspot.com/2009/11/bamboo-bicycle-construction.html

Contour, read through this thread too: http://www.bikeforums.net/showthread.php?606960-carbon-fiber-build

Contour, if you're creative, you can get everything lined up appropriately with out an expensive jig system. It's not very practical, so it would not be efficient for mass production, but for one offs I'm sure you'll think of something.

Thank you,
phil

I made a bamboo bike recently and the process is remarkably simple. You can align by eye if you're used to doing any work that requires some experience with this. My bike tracks perfectly.
I used bamboo from a flower shop and a garden center and chopped up a few steel frames for the necessary parts.
I didn't bother with heat treating. Tests show that as soon as you heat bamboo to a darker color you significantly weaken it (although it does become stiffer).
You will notice that bamboo poles in a typical selection may be splintered and cracked or perfectly sound. Since the sound bamboo has probably been sitting for several years through a huge range of moisture and heat cycles without cracking you can be more sure it will continue to do so in the future.
Imported bamboo has already been fumigated twice for bugs so it is hardly necessary to do that.
A good finish renders it impervious to moisture and appeal to insects anyway.

For gluing I would recommend going by a proven Epoxy system. I like System 3. Resins. They have an appropriate Epoxy for every application in the process and though it may not matter they are all likely more compatible with each other than using types from several companies.
I wrapped the lugs with a combination of Fiberglass, Carbon cloth and Manila hemp(for the natural look).
You need to cover the metal parts with glass cloth before you wrap with carbon. As far as tow versus cloth, by the time you finish wrapping a lug with tow it IS practically woven.

As far as worrying about torsional stiffness, I wouldn't. If you try to bend or twist a short length of bamboo tubing it is unyielding. If you wrap your lugs well they will increase the stiffness. With the ends of the tubes locked in place and all braced against each other the accumulated strength of all the parts is incredible.
Once you build one you will start replacing all your other bikes with a homemade version. I'm working on my TT bike now.
Interestingly I'm probably riding the only bamboo bike in Toronto right now and people don't even notice it.

Canaboo, can we get some photos to drool over?

http://i399.photobucket.com/albums/pp78/pat_05/CIMG4903.jpg
http://i399.photobucket.com/albums/pp78/pat_05/CIMG4904.jpg
http://i399.photobucket.com/albums/pp78/pat_05/CIMG4906.jpg
http://i399.photobucket.com/albums/pp78/pat_05/CIMG4907.jpg
http://i399.photobucket.com/albums/pp78/pat_05/CIMG4908.jpg
http://i399.photobucket.com/albums/pp78/pat_05/CIMG4909.jpg


Here's a few. Sorry it's a bit dirty from riding on dirty roads. Not really drool-worthy but a good basher for rough roads. The parts are very low end in case somebody gets the bright idea of hacksawing it to get the parts.

Very nice!
What resin are you using?
What's your build process, tape, vacuum bagging?
How much clean up did you do on your lugs? They look swank.

More, I must have more.

Seriously, that's a sweet bike.

Thanks. I just tacked this bike together with the same resin I wrapped it with(MAS Epoxy). I had some carbon and glass tape which I used as an initial overlay of all the lugs and then wrapped them twice with the Manila. After the first layer cured I sanded them and then applied one more thin layer of Manila as neatly as I could, sanded them again and smoothed on one more layer of resin.
I used inner tube strips in place of vacuum bagging. That compresses the matrix and squeezes out the excess resin. After it cures the tubing peels off and the surface is very smooth and only needs any ridges of resin flattened.
I did sand the ridges of the nodes down since the bamboo wasn't the greatest in quality. That doesn't weaken it if you just knock off the lip of the node and don't try to completely flatten it. The bike is very stout. I can place my hands on the top tube and bounce my weight onto it with no signs of creaking or bending.

Hey canaboo. You have inspired me to build a bamboo bike like yours. I located a old centurian road frame that I will be using as a doner fot the BB, HT and dropouts. I'm having some trouble finding a source for the bamboo. I live in MA and can't seem to find any growing beside the road. The online places seem to require a fairly large minimum order.Can anyone point me to a good source of bamboo?

www.bamboofencer.com has bamboo poles. Tonkin is a good choice for smooth nodes and all around strength and resiliency. It's the type used for making fishing rods.
I managed to get some up here and it is incredible stuff.

Thanks for the info. I ordered the bamboo today.I also ordered all the neccessary metal bits from Nova.I am working on drafting a full size blueprint and building a jig so that I can start assembly when the material shows up. When it comes time to wrap the joints I will asking more questions on this forum because I have not worked with composites before.

AllenG, I liked the dropouts that **** designed for his friend, they look very similar to what Calfee uses, at least in terms of the bolt adjustable angle. Been following this thread, kind of lurking, and the question that I have is what kind of drop outs are you guys using on your bamboo frames and how are you attaching them to the stays? It seems that most dropouts that I can readily find on the www are pre-made at a certain angle for the stays and not easily adjustable. I wold love to get my hands on some similar to what Calfee uses, or that **** guy.