We were extremely happy with how our first prototype wood bike turned out at the end of last year. It looked great and the ride was amazing. I did about 50 miles of hard city riding on it before the weather in Buffalo became too cold, at which point we began bench testing for strength. We were thrilled to pass the strength test with this first design, but we wanted to make the next prototype even stronger. Being a primarily wooden frame, we want to eliminate any misconceptions about the strength of wood by making a bike that far exceeds the standards.
This second prototype wood bike is a huge leap forward in strength. We use a pneumatic cylinder to apply force at levels that a rider would likely never see in order to protect against extreme conditions. This time around we nearly doubled the amount of force that we loaded the first prototype, and the frame held up perfectly. It doesn’t flex much overall, but check out the bending of the hard maple tubes in our video below. We had to stop only because we had maxed out the limit of our pneumatic cylinder!
There are a bunch of updates to this latest design which contribute to the increased strength, but the major two points are adding Kevlar and carbon fiber reinforcements inside, and machining the joints from thin layers of laminated birch (actually just Baltic birch plywood). Conceptually both updates work great, but unfortunately we feel as though the Baltic birch plywood ruins the aesthetic of the frame. Even though it’s high grade plywood with consistent layers throughout, it still looks like plywood once it’s done. This just doesn’t work for the handmade, highly engineered frame that we’re developing.
Instead, we’ll take the concept of laminating layers of wood with alternating grain direction and hand-craft our own “plywood”. This allows the use of any species of wood while keeping the strength benefits we found in our latest prototype. Here’s a preview of what this will look like, half finished (literally) and taped against the last prototype for comparison:
With this milestone complete we’re one step closer to production testing so please check back soon for more updates!