I have a road bike with Shimano Claris shifters and deraileurs.
I bought the bike new and everything has been 100% for about 3 months of good riding. I have noticed that shifting into the big chainring on the front needed me to move the shifter more and more over time. Sometimes I pull it far enough to click but the chain doesn't move up to the big ring.
The shifter itself also feels a lot looser than the other side, like it has some slack. I have been forced to use my other hand to pull the shifter as much as possible and then it moves up.
What should I be adjusting: the tension on the wire (undo the tension bolt while it is in the small ring and tighten it up) or the barrel adjuster? Or something else?