Francois_Viviers wrote:A hole in an I beam? we are comparing a metal Ibeam to a function specific carbon crank. An I beam was engineered to have strenght in its design therefore cutting a hole in it would bugger it. These carbon cranks have been engineered to have a hole in it, and with the structural design freedom that you have with sheets of unbonded carbon I am sure you could make this work. Only a test would tell
Of course
: that's what I said: I-beam; box beam; truss; glulam; rope bridge; laced frame; carbon crank: whatever: it's all structure, and all are function-specific: if an opening is required, obviously that can be accounted for in the design/engineering, and I'm pretty sure Stronglight engineered and tested this
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What were the strength/stiffness parameters they tested to, what is the internal structure? I don't know, it would be nice to find out: could be brilliant, could be a noodle.
In the last few years cranks have gone from +/- 700 g to +/- 500 g, claiming high stiffness, some succeeding. So I wouldn't discount this design per se, but with all these superlight cranks it would be great to have independent and strength/weight/stiffness comparative tests, I agree.