I've had the creaky crank problem on every bike I've owned which has
had cotterless cranks.  Until now, I've never known a good solution to
the problem.  

One suggestion I had was to replace the crank, but that wasn't
something I was prepared to do on 1 month old bike under warranty. 
The shop mechanic spent half an hour with me and my bike sorting it
out.  Tightening the crank bolts and pedal spindle (i.e. onto the
crank) didn't help (as Jobst will tell you).  

Removing each crank, smearing the spindle with grease and replacing
the crank eliminated most of the noise.  Removing each pedal, smearing
grease on the thread and replacing it got rid of the rest of the
noise.

Greasing the pedal threads is a new one on me, but it makes a lot of
sense, since they are steel and the crank aluminum.  I thought it was
worth relating this story, as creaky cranks seems to be quite a common
problem.

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