My bike has Shimano Deore DX shifters and derailleurs. The front shifter had issues and I tried to open it up and fix it, but destroyed it in the process, so I'm looking to replace it. I've never done this before, so I'm not sure what I need to purchase. I assume I can just buy a new pair of shifters (the current ones mount to the bottom of the break lever assembly), but I don't know what I should look for. What are the specs I should be looking for (the gears are 3 in the front, 7 in the back)? Do I have to get Shimano, or will another brand do? I'm not using this for competition, just commuting.
Please let me know if I need to provide more information.