Originally Posted by
zeo_max
I have a MTB with a 3 x 8 drivetrain setup and when placed in the tallest gear combo (biggest cog up front, smallest cog back) the chain rubs against the front deraileur's wall, or side, whatever you call it. Is this normal ?
No, this is not normal at the gear combo you described. You need to do a front derailleur adjustment. Go to Park Tool's website or Bicycletutor.com to see how to adjust the front derailleur.