Bamboo bicycle build - sourcing materials!
So far our bamboo bicycle project has been an incredible experience. We've been meeting and sharing information with some wonderful people. First of all, Eric has joined us here in Portugal coming up from Morocco. On his way up here, he stopped by Bambuparque, picking up 30 meters of iron bamboo. Florent, an adventurous man from France, contacted us through thepoosh.org and came down here during his break from school to help out with the build. He stayed for about three weeks and recently went back to France where he's studying energy and environmental engineering. He was a great help and an even more wonderful person and hopefully we can stop by his place on the tour so he can see the finished bicycles. Cristina, a Spanish woman, got in contact with us through a Couchsurfing group and just arrived a few days ago. She is very interested in building bicycles out of bamboo and might be riding with us for part of the tour.
The main focus of the project so far has been gathering materials which we are trying to do as locally and as sustainable as possible. Iron bamboo is unique in that it is very dense and has very small voids, some pieces not even hollow at all. It is known to be one of the strongest strains of bamboo along with tonkin bamboo. There are two pieces on our bikes that this type of bamboo would not work for. We needed a bigger hollow piece for the bottom bracket casing to hold the crank for the bike and a hollow piece for the head tube which the front fork and steering column can fit into. After inquiring from many people where we can find bamboo, I walked one kilometer down the road where someone had a small patch of bamboo. When I told them I only needed two meters of the correct size, they responded, "for that mucch, you would not even need to ask." Wonderful!
A good amount of our time has been spent heat treating our bamboo. Fortunately, there's a cob oven where we're staying that has proven to be perfect for this task. It is important to maintain a very small fire inside, not getting the oven too hot or the bamboo will crack and lose it's strength. We've also been propping the bamboo on a block or on one side so the pieces are angled allowing the moisture to escape the bamboo. We haven't been closing the door on the oven because then the moisture wouldn't be able to exit, leaving a humid oven.
We were originally planning on using hemp fiber to wrap our joints. Trying to find hemp fiber locally was fruitless but in the end we learned of some alternatives. The first fiber we were told of and tried were the fibers from a tall, flatleafed cactus that grows in the area. It's often used for bundling harvests or anything you need to tie with instead of using string. Although very useful, it didn't seem to have the required strength or durability that would be required. Next we found someone with linen fibers which we got a small sample of and tried it on a joint. This seemed to be very strong and after some research we found that it is very similar to hemp fiber. So we went back and got three or four kilos of linen fiber, which should be plenty for our bikes.
Collectively we all spent about a week going out to the pine forest for a couple hours on pine resin collection missions. We would search around for a wound or broken branch and cut out a portion of the resin that collected there. The other two parts of our glue mixture were easier for us to come by. We planned on getting our wax from the bee boxes but we found some beeswax packed away in the storage shed. Charcoal was also easy to come by since we've been sitting around a campfire most nights. It took a few tries to get our mixture how we wanted it. The first batch didn't seem to work well and was crumbly since we used ash instead of crushed up charcoal. Then we tried a mix of about 3 parts resin, 1 part charcoal, and 1 part beeswax but it seemed to be brittle so we thought adding more beeswax would give it more flexibility. It turns out our intuition was correct and after adding a good amount of beeswax probably bringing it up between 2-3 parts beeswax, the glue seems to have the strength and flexibility we needed.
Finding bike parts has been the most difficult for us to obtain. There are some parts that we can't or wouldn't know how to make out of natural materials, such as derailers, brakes, wheels, chains, cranks, etc... We've been visiting bike co-ops, bike shops, and anyone else that works with bikes to try to sort parts. We've gotten a good portion of the parts but we still need more.
In other news, the Co-operativa next door asked us if we would like to build a yoga studio for them out of natural materials. We've been very excited about this opportunity and it will be the first stop for the tour, next door. We will be starting the build at the end of March and will share with you a bit more about that build in blogs to come. So now that our bicycles are close to the point that we can start assembling them, we will be splitting our time between building the bicycles and also getting prepared for building the yoga studio.
Loren Heacock from the POOSH Team!