I like this one because of the wording.  I believe Crankshaft is neither straight nor crooked myself.  Maybe I should take more time to compare myself to this riddle.

I can brake down the second sentence and it gives Crankshaft meaning as well.  As for why I have to cross the bridge I don’t know.  Maybe because the bridge is made of wood and and straight lumber and the water underneath is crooked in the turning stream.  I’ll have to think about how that would give you the answer.

I will probably still have to post the answer.