by Kiro Hadjiev –
Bamboo is an amazing bike frame material: stronger than steel, more durable than carbon fibre, and more flexible than aluminium. This is a natural material which grows by itself from the ground and unlike the other three does not require heavy machinery and excessive pollution to produce. It is also a carbon sink as it captures carbon from the atmosphere and keeps it locked in for as long as the material stays intact. If treated properly, bamboo will last for a long time, will not rust or suffer fatigue. These days some companies are selling bamboo frames with a lifetime warranty.
My first bamboo frame did not last a lifetime. After a year and a half of riding and even surviving a car crash, the headtube cracked. The frame is hanging on the wall at home and I am still wondering how to fix it. It was not the bamboo that failed, but the lug made of hemp and epoxy. The failure most likely due a poor design, or maybe just because it was my first attempt. My next frame is going to be a much better one!
The first build stage is pretty straight forward and it requires a lot of time and patience. It is all about measuring twice, then measuring twice again, and then cutting. A lot of carving with a sharp knife as all joints need to fit perfectly. After a day and a half of frame shaping the result is sitting comfortably in the jig looking nearly complete.
The second build stage is about wrapping the lugs with hemp and epoxy. This has to be done quickly and requires a lot of focus. The process is simple: mix the epoxy; soak in the hemp strips; make the lug by bandaging the joint with multiple layers of soaked hemp strips; repeat until all joints are covered.
Next is waiting until the epoxy sets. After a day of drying the frame is ready to ride. But there is more work to make the frame look nice. Two more days of sanding, filling in, polishing and lacquering and finally, the frame is ready. You can spend a lot of time and filler making the lugs look artificially smooth. This does add weight and, I think, distracts from the natural form. So not quite everyone’s cup of tea!
The finished frame weights 2.2kg. Add a few bike bits and, voila – a new bike is born! The wheels are handbuild with a 3-speed Sturmey Archer hub and a dynamo for the lights. The chainring is steel and there is a chain cover so that the single speed chain lasts longer. I also chose flat bars, as it’s build as a town bike. It looks awesome and it rides smooth.
So, was it worth it?
Yep! The whole process takes a lot of time and it is a bit nerve wracking, especially when making the lugs. But the result is extremely satisfying. Not just because of building something usable from scratch, but also because it is so fun to ride.
And I have already ordered the parts for my next bamboo frame…