I've finally found the time to get this one started.

It will be a drop bar disk road/cross bike. Well, more a road bike but with a commuter/cross fork with lots of clearance. Using my 10spd Ultegra carried over from the previous bike, so it will have mechanical disk brakes.

New build table is mounted on an architectural drawing board stand which will allow me to raise and lower the surface as well as tilt it to vertical.

I'm also trying a mitred tube lug method instead of the previous balsa wood lugs with butted tubes.

Chainstays might take a while. I've dreamed up a plan to make a curved shape by cutting a large tube diagonally to give a tapered half oval segment, then bond two of these together in a curved jig. I'd put braided carbon fibre tube reinforcement in the hollow and compress it using the long thin balloons that folks bend for kids parties.

Here are some photos of my first efforts with the mitre cutting tool. It's not exactly precision engineering, but that's the beauty of working with bamboo - I can file or sand things a bit later.







Down tube meets the head tube. I'll move this down a little more.



Bottom bracket

Good to see some bamboo stuff happening on here again. Your chainstay idea sounds overly complicated. You can just find bamboo that has grown in a flat oval shape and bend it with a heat gun.

It is overly complicated, but probably easier and more reliable than searching out some strange shaped stuff!

I'll let you know how it works.