Two fold question. MTB has 7 speed cog and 3 chain-rings. Shimano Deore LX rear derailleur and Acera front derailleur with rapid fire shifters.
First, the right shifter will now only index four cogs. I've checked and adjusted the rear derailleur and even when cable is detached the shifter will only advance or descend four clicks. Is it repairable?
Second, can I replace the rapid fire shifters with grip shifters?