Gaetan7TB4

Hi all !

I create this post to share my first bamboo bike, hope you will like it. All comments are warmly welcome, since I am a beginner in this area I have a lot to learn !

For the technique :
- copy of an existing frame
- no jig used at all : cut one tube, replace it with bamboo
- inserting a few centimeters of each metal tube inside the bamboo
- wraping first with aramide roving : much more "user-friendly" than my carbon roving, which was really fluffy (pic in thumbnail)

- wraping then with 24K carbon roving









- wraping finally with 2x2 twill carbon weave


Fixie style : easier for a first frame ! No brake mounting, no gear mounting either...

I unfortunately did not take the time to take a lot of pics, so I will present you a few steps :

As you can see, the details are not that good : not sanded enough the lugs, they are not really smooth. I really did not have that many tools ! A saw, a vice, bamboo, aramide and carbon ^^

Finished bike :


I will try to post another frame I did since this first one. unfortunately, the second frame is really bad compared to the first : I tried to make a women city frame (the top tube being really low and reaching to the rear wheel) but the feeling is really wobbly.

Hope you like my first bike !

Many thanks to JohnnyHK who kindly helped me when I had a lot of questions !

JonnyHK 

Enjoy riding it.

Looking forward to seeing your next effort.

(and buy some more tools - a man can never have too many!)

unterhausen

thanks for posting, looks good

Gaetan7TB4

Thank you for your comments !

I actually bought a lot of tools since the first frame, it was really a pain to work with almost nothing !

I built a aluminium frame to make a second frame with my own measurements. I'll just change the name of the topic and post my second frame here !



For this pic, I tried to use peely ply to have a good sticking surface for the next layer of carbon tow. It works quite well but I had trouble taking of the peel ply !


Finished frame


Finished bike. Note the (way too) high BB




For this second frame, I tried a lady construction, with 100% home-made measurements, and that did not work well ! I made a mistake with the BB drop, so in the end the BB is higher than the rear axle.

I don't know if this is caused only by the high BB, but this frame is sooooo wobbly, really hard to drive with confidence. I am pretty disappointed with this frame, but hey, that is the hard way to learn ! I tried a different approach with my joints, they are much smoother, but I think I prefer the satin weave style from the 1st frame.

I added 3 coats of PU varnish, that works great on the bamboo, but on the joints, they tend to go milky grey instead of true black. Any clue on how could I do that ?

And again, all comments are welcome.

Merry christmas to you all !

Gaetan

Canaboo

The mixte style is always going to a be a bit more flexible so you really have to select your bamboo to have thicker walls or larger diameter.
The high bottom bracket isn't going to be the culprit for making it wobbly.

Not sure why the joints are going greyish but you could try washing all the sanding dust off the joints first. It may be mixing with the varnish to get that muddy look.
Coating with Epoxy first will always give better results.
Merry Christmas!

JonnyHK 

Cool.

Was thinking of doing a mixte for the wife...

Gaetan7TB4

Hi frame builders,

First of all : Happy new year to you all !

About the mixte style : I was pretty disappointed by this soft frame. I will try with Iron bamboo next time, I am waiting for an order of these bamboos. Otherwise I was thinkg of doing a slopig frame, so I have a "regular" geometry of frame, but with a lower top tube so my wife can ride it safely.

About the grey joints, I was probably a bit messy, I'll try to sand it and clean it more thoroughly next time. Thanks for the advice Canaboo !