I love my Downtube NS-9 and
hammer it daily for a 10mile to and 10 from
commute. Its totally flat here but you can still feel everything flexing like Gumby
In a hilly situation I suppose this would be even worse. But to be fair, a search using the
word 'crack' in the Roadie forum would show plenty of hyper-$$$$$ expensive bikes of
all types of materials crack too.