bamboo bike...

warcricket

Like a Jerk
okay, so for the last month i've been slowly gathering supplies and stuff for my winter project, a bamboo bike (probably fixed maybe ss).

so here's the plan. I use an old ass bridgestone frame i have lying around and saw off the entire top, seat, and down tubes aswell as the center portions of the seat and chain stays. i will then attach the bottom bracket shell, drop outs, head tube, and seat tube collar with bamboo rods (cut at the same length as the beams that they are replacing and bound with either carbon or hemp fiber.)

so far i've managed to gather a significant amount of the straightest bamboo rods i could find. You'd be surprised by how much bamboo is growing in random public places...

heat treating the bamboo

the next step is to prep the wooden rods...

from what i've gathered, heat treating is a two step process in which a blow torch is used to dry out the wood. the first step being to change it's color to a yellowish tan, followed by a week or two for drying and retaining shape, and then another torching to turn it a light brown color.

so, the wood has been sitting around in my garage for the last week and i've came to the conclusion that my pops is never gonna remember to bring his blow torch home from work. restless as i am, i began to treat the bamboo over a gas stove.

i just finished the practice piece, and the treating was needless to say a bit uneven. oh, and the bamboo exploded... I'm guessing what happened was that since the nodes (ring shaped things) of the wood are solid throughout the plant and separate the hollow chambers of the rods, pressure from the heat built up in the space between the nodes and caused the bamboo to pop and split in my hands. For the next rods, i guess i will have to puncture the nodes to allow the wood to breath better...

pics to follow as this project progresses...
 
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THATmanMANNY

Well-Known Member
someone should have mentioned to you that moisture gets trapped in the nodes :D bamboo sucks up lots of water

I think I would go SS. I have no data to say what I'm saying it right but it seems there would be less "force-feedback" on the fragile frame when you try to stop by skidding unless if you're gonna run brakes or just coast to a stop which the later 2 are not your style haha

build me one while you're at it ;)
 

warcricket

Like a Jerk
kay, picture time!!!

Ancient Bridgestone frame and fork i got off a friend, cant put a finger on the date, but it's built for 27inch wheels so maybe pre 1980??? 56cm.
DSCF0905.jpg

ghetto blow torch
DSCF0909.jpg

practice piece that snapped due to built up pressure
DSCF0908.jpg

solution: drill a hole in the node
DSCF0906.jpg

before/after first heat treatment tt,st,dt
DSCF0919.jpg


manny, i was thinking the same thing about stress in the chainstay if it was fixed. so it's probably gonna be an ss. I also am considering just leaving the chainstay as it is.
 
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clarkenstein

JORBA Board Member/Chapter Leader
JORBA.ORG
this is awesome WC. i have toyed with the idea of shaping a surfboard out of bamboo (plyboo actually - plywood made from bamboo). bamboo is good stuff.

for example:
lobster_shaka.jpg
 

Wobbegong

Well-Known Member
Adam, I have a spare torch head you can use, I'll bring it Sunday. All you need in a small propane tank from home depot and your good. You'll be able to get an even result with the torch.

JP.
 

bonefishjake

Strong like bull, smart like tractor
Team MTBNJ Halter's
anrothar would be proud of you. i don't even think he got to the exploding of bamboo stage.
 

stb222

Love Drunk
Jerk Squad
pretty cool stuff....

I will give you credit, you are into some cool stuff for such a young'n
 

warcricket

Like a Jerk
http://www.instructables.com/id/How-to-Build-a-Bamboo-Bicycle/


I'd be super careful about riding it. I built up a carbon fiber bike in my basement and it was great. I got really confident riding it and then it snapped in half on the road when I hit a pothole so.....rider be warned ;) bicycles made at home are done so at your own risk! :rofl:

how many layers of carbon fiber did you apply? i'm thinking of around 10... also, did you follow the bme instructable for working with the carbon fiber?
 

warcricket

Like a Jerk
Adam, I have a spare torch head you can use, I'll bring it Sunday. All you need in a small propane tank from home depot and your good. You'll be able to get an even result with the torch.

JP.

thanks man, but my pops finally brought it today so i'm set!

i finished the seat stays today with the blow torch and boy did it go a lot smoother with the new tool.

i forgot to mention before how cool heat treating the bamboo actually is. the whole time you're doing it, steam flows out of the rods like a choo-choo train and the wood oozes like crazy with super sticky juices. I wish i could have taken a picture to do it justice.
 

ellbiddy

Active Member
how many layers of carbon fiber did you apply? i'm thinking of around 10... also, did you follow the bme instructable for working with the carbon fiber?

No, I used the original rinard guide. I used many more than two in high stress areas (BB/joint points) I used anywhere from around 10 to upwards of around 18. I had two real goes at it, the first one was a mess and I scrapped it. I'm the middle of designing my next commuter bike again, this time with some experience under my belt should go a lot better. Also having a normal frame jig helps. I have LOTS of extra fiberglass laying around if you need any, I use the really thin stuff to insulate the metal parts from the CF and the thicker stuff to insulate a foam model, the only source of urethane foam supplied 2 lb "density" foam and it was way way way too soft. Shaping and securing the dropouts was a major headache as well. the new strategy is to embed the seat and head tubes directly instead of as an after thought. Also sanding was a major issue when glue urethane glue jobs got messy. The urethane glue cures MUCH harder than the foam so it was very very difficult to sand without screwing things up in the process. What I was thinking about doing now was making a lugged version where I would lay out the tubes as I want them then cast the ends in fiber glass, and lay up the CF on that using bits and pieces of foam to shape the general shape of the headtube and what not. The problem being that I can't really get those nice curvy shapes that way.

The other-other option is to make a mold and go that route but I don't want to invest in vacuum pumps and what not.

My current plan is to piece together each tube in the shape (curvy) I want ensuring symmetry in heavier foam leaving the ends "extendable" so I can cut/fit them in the jig to fit the geometry I want.

Edit: If you're interested in various frame parts I have a collection of really good websites for parts. I would also search the cycling framebuilders email list, they have talks about composite bikes a lot, really helpful guys.

Double Edit: Don't get into this unless you're willing to take a pretty hard fall when your frame fails. Also don't get into this unless you really thing about safety. Sanding/cutting CF isn't conducive to your health so everything has to be done with care.
 
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THATmanMANNY

Well-Known Member
THE bamboo bike

Damn dude. Whatever you build and work i will give you a big pat on the back and maybe even buy you a cake but you can't F with this bike..

I was up in Greenwich, CT pass couple of days and stopped in Greenwich Bicycles. The owner rides this! Calfee Bamboo Bike (coincidence?) with record 11 speed! I talked to him a little. Frame costs $2.5k+ & loooong wait list, bonds are hemp and resin (you should think about it), & alum inserts here and there. And his whole set up weighs 18 pounds! Even the cages are wood! :eek:

-The shop is pretty sweet too. Carries some exclusive makes like colnaga and guru and other just WOW bikes.
-I also drove up to the NW area of CT... OMG that looks like some epic road riding.

BTW... all they drive in Greenwich are BMWs, Benzs, Bentleys and Astons. DB9 below (god I want :drooling:). It is totally ridiculous!
 

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MattyJay88

Guest
that calfee is sick! so is the Aston. Good luck with the home build!
 

warcricket

Like a Jerk
i can guarantee you that the end result will look nothing like the calfee.:drooling:

over the last couple days i've been treating the bamboo every now and then.

today went a tad like this:
DSCF0927.jpg

filled the top tube with polyurethane foam for added stiffness
DSCF0920.jpg

then i took the frame
DSCF0921.jpg

and sawed off the top tube (notice my friends super modeling stance)
DSCF0922.jpg

and replaced it with a rod of bamboo

i only did the top tube today and didn't glue it on either. tomorrow i'll finish the front triangle and secure the pieces into place. i should also be ordering the hemp fiber tonight.
 
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