What made you decide to build a bamboo bike?
I wanted the challenge of building my own bicycle from scratch and learning a lot of new things along the way. I also wanted to be able to customize the geometry.
Did you enjoy building the bicycle from scratch and would you recommend the experience?
Yes. I had so much fun figuring out how to solve various problems and the experience was very rewarding.
What did you find most difficult about your bike build?
Making the flax/epoxy lugs was one of the most difficult parts. I tried to plan out wrapping the lugs and even practiced the wrapping pattern with some dry fabric ahead of time but it was difficult to get an even thickness in certain areas. Although the wrapping seemed pretty even while I was putting it on it would appear a bit lumpy after compression with electrical tape. I also felt pressured for time to get the flax wrapping and compression with electrical tape done the way I wanted even though the epoxy working time was about 30-40 minutes and I mixed up a separate batch for each lug. In the bottom bracket area I made things a bit more challenging by wrapping the cable tubing around that area which created concave areas that were difficult to compress with the electrical tape. I ended up going through several cycles of sanding and adding more flax and epoxy to cover the thin spots until I was happy enough with the shape and lug thickness. Another aspect which I puzzled over for a while was the sizing of the frame. I wasn’t sure if I should start with the medium or large kit and ended up getting the large kit. After cutting the tubes for the front triangle according to the original plans and holding them together with some tape I realized the reach would probably be too long. Based on comparison to my road bike I decided to shorten the front triangle by about 5cm which required recutting the top tube and down tube. I also lengthened the chain stay a little bit. As I wasn’t very confident in my modifications it made me a bit anxious to see how the bike would fit and ride in the end. Alignment and spacing of the rear triangle was one of the most difficult parts as the diameter for the chain stays is quite large and I was trying to avoid having to create cutouts for tire or crank arm clearance. It helped to create a scale drawing including the tire and crank to figure out where the chain stays should attach to the bottom bracket. Another thing that helped was to make some L-shaped pieces out of PVC pipe to check the wheel location and crank arm location while aligning the tubes in the jig. While checking the alignment I discovered that the jig holding the dropouts was not at a consistent height with the other three jigs and ended up shimming the other three jigs about 2mm higher to compensate.
What was the easiest part of the build?
The easiest part was putting all the components on the frame. Aligning the rear disc brake caliper using the IS-FM adapter was a little tricky but I was able to get that done with shim washers.
How would you describe the ride of your finished bike?
I was very happy to find the bike fit was comfortable and the handling quite stable and easy to control. While the frame feels very stiff and not floppy at all (probably helped by the large diameter tubes) it also seems quite good at damping vibrations from bumps in the road. There are also no unexpected noises. After a few short trips around my neighborhood and jumps off the curb I'm pretty confident that it will be safe to take on some longer rides. I tried to provide enough clearance in the rear to fit a 33mm wide tire but this left only about 2mm of clearance between the crank arm and the chain stay. I was concerned that flexing of the frame might lead to the crank hitting the chain stay but after pushing the pedals quite hard I don’t see that happening at all. I did feel I needed a little more heel clearance but solved that by adding pedal spacers.
What would you improve about the build experience or your finished bike?
While the instructions were overall a good guide there were some places in the instructions where I could have used more details or suggestions for alternative ways to do things or optional enhancements. I’m still not certain what caused the issue I had with the dropout jig appearing to be shorter than the other three and I was able to fix it by adding shims but it would have been better if I didn’t have to do that. I realized too late that I should have covered the dropouts with some tape to avoid getting epoxy on them but was able to clean them up later. As I was building from the home build kit I didn't get much choice about which bamboo poles to use and I think being able to choose from a larger selection might have improved my experience. I tried using a little bit of low density epoxy putty to help smooth the shape of the joints before wrapping which I think helped to give the lugs a nicer shape and next time I'll probably try using more of that.