I wonder about that. I've ridden a carbon wrapped bike through hot and cold extremes for years.
I wonder if Calfee is curing his bamboo long enough and sealing it adequately. When natural material cures it tend to continuously shrink through each cycle of dampness and dryness.
That's why tool handles eventually loosen despite being dried adequately before intial installation.
Yoiu can get bamboo or wood "dry" quickly and it will still shrink gradually over time.
If Calfee only treats the bamboo with satin polyurethane then that's not nearly enough to slow the moisture cycling to negligeable amounts.
Things like this are why old time craftsmen working with natural material demanded that it be cured rather than just dried.