Taking SCARY out of used bikes, one bike at a time.
When buying a used bike or your bottle cage mounts get loose or striped, the mounts can be replaced. What happens is some accessories get too heavy for these mounts (like e-bike batteries), or your cage gets hit from the side. The braze-on support gets damaged.
First, you need to cut them out. This is tricky, and being surgical is the key. Tape the frame to protect the paint, cut the top off with a small grinder or saw. Pieces will fall in the frame which you will need to pull the Bottom Bracket to get those out. You will need to remove them unless you like rattling sounds.
Then once cleaned out. You will need an installer it put in the new mounts. They cost around $60-$100 for the tools and parts. Make sure it’s metric size. Check with your local shop to have them installed, the cost may be less, but it does take about 2-3 hours to do it right.