I just got a used 2011 Trek 7.5 FX and have a question about the indicator on the rear shifter, I believe the shifter is a Shimano Deore SL-M530. When the red indicator bar has traveled as far to the left as it can I can still change to a lower gear, similarly the indicator bar never reaches the far right side. Everything works great, it is just that the indicator is not calibrated correctly. I am sure that as I get used to the bike I won't even look at the indicators but regardless: is there a simple way for me to adjust the indicator bar position? Thanks in advance!