Originally Posted by jimmuller

From the standpoint of how it affects gearing, switching to a 175 crank from a 170 is like increasing your largest sprocket from 24T to 24.7T. However it will decrease your pedal to ground clearance by 5mm. If you adjust your saddle height for the bottom of the pedal stroke it will lower your body position by 5mm, which may help with stability. Finally, assuming you re-position your saddle height it will increase the bend in your knees at the top of the pedal stroke. For this reason some of us (not necessarily me) don't recommend it. Your knees may vary.