Someone was describing to me today that you can take bamboo, denature it's bamboo-form somehow, then compress it into other shapes. There are two curves there, one obviously two pieces and the other one possibly two pieces, or simply one piece that was-re compressed into the oddly sharp curve you see. Since stuff was made with machinery, which is cooler on one level, but also less cool than some of the natural bamboo bikes I've seen on instructables
New to endless-sphere? Notice a lot of signatures recommending Ebike.ca? That's because it's the best place for a quality and manageable, (but still 'real'), first build. Justin is a solid supporter of electric bike development, and a good source of equipment.
My hat off a thousand times to the green people that effectively run this forum. The ES Mods are superb.