Please feel free criticize this if you don’t think it will work. I’ve already built a mountain bike using bamboo. I mitered the bamboo tubes to joints with 4130 steel. Initially I used raw hemp fiber/epoxy to make the lugs around the joints. Instead of vacuum bagging, I only used electric tap and wrapped tightly around the hemp/epoxy. After 3 rides, the joints failed in 4 areas. I then reworked the joints using 1k carbon fiber tow and used since I still don’t own a vacuum bag system, I used electric tape again. I check the lugs for cracks after every ride. 7 months of montain biking and the carbon lugs are still holding up.
So here’s the problem. I learned that the reason Calfee stop using carbon for making lugs on his bamboo bikes because the differents rates of thermal expansion of bamboo and carbon fiber causing failures for his bicycles. I’m no engineer so I don’t if it simply meant that the carbon fiber lugs cracked. He now uses only hemp/epoxy. Even though it’s easy to work with, I don’t want to use hemp fiber again.
What do you guys think of using stainless steel fiber/epoxy lugs for the joints? Would it just ending weighing too much and still not be as strong as carbon fiber? Thoughts please.
