How I built a carbon bike frame at home (and a bamboo frame too)

Step 10 Building the bamboo/carbon frame 2

The most difficult part of building the frame was to find quality bamboo rods. It took me much more time than the building itself. I have visited several dealers in near surroundings and I have tried to find appropriate rods of the necessary diameters among huge amount of bamboo. Finally I have found few rods I wanted, but frankly speaking, next time I will build such a frame, I'll rather grow my own bamboo, or fly to Asia for it. The rods for the top tube, down tube and seat tube are some Chinese species of bamboo; I was not very satisfied with the quality of the surface, which was rather scratched and there were also a few woodworm holes in it. The rods I have selected for the seat and chain stay were some other species from Malaysia. Unfortunately the seller was not able to tell me what species it exactly was. During breaking tests of these bamboo rods I found out that when I filled the inside with the polyurethane foam (which added only few gram of weight), the rigidity increased mainly of the rods for the seat and chain stay, which are the most critical parts of this frame.

Comments

[rudi.carfell]

Hey, Big thumbs up for your bikes... I'm Miro from switzerland and I'd like to build one to: http://bambusrad.blogspot.com My question is which diameters have you used and how did you get to them? I see you haven't heat treated your wood, how it's advised on the instructables here on the website. What persuaded you to do it not? It works, don't it? And could you write me a link or something where you bought you polyurethane foam? I would be very thankfull(y(?))... I'm sorry for the bad language.. :) Greez Miro

[gastlyfellow]

 Love your bike, and I am thinking of building one after I get done with my cedar strip canoe. 

Questions:
I would like to see the shapes of the carbon fiber you cut, before you used the resin. Did it overlap itself, and how did you decide where to have it overlap? Do you have any recommendations for best ways of cutting the shapes?

How exactly did you go about filling the bamboo with foam?

[dominic.tarr]

ah, i had been thinking of foam filled bamboo for sail boat spars, how much did strength increase? can you describe the method you used in your breaking tests? cheers- Dominic