I suspect the main deal is that it depends upon what kind of bamboo is used. Some is suitable for structures, some is not. Most folks think of the bamboo that's mostly hollow, but the structural bamboo can be almost completely solid. I suspect for a bike frame with such short lengths, you could get away with a compromise.
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Steve
'08 Boxster RS60 Spyder #0099/1960
- never named a car before, but this is Charlotte.
'88 targa

SOLD 2004 - gone but not forgotten