Originally Posted by
gravelED
Maybe I'm describing the problem wrong. The bolt cannot be removed. When you attempt to tighten or loosen the bolt, it just spins with the rivnut. The video makes the repair look easy, but in this case with the bolt fixed in place it looks like the repair requires drilling out the bolt.
Thanks very much for the clarification. That's a bit trickier. If the problem occurred after first removing the bolt and then tightening it to secure the cage in place, you might have overtightened the bolt, but no matter. (For future reference, always grease the threads of the bolts before installing the bottle cage.)
When I worked in bike stores many years ago, I fixed a few seized bolt/rivnut problems without resorting to drilling, but you probably should just let the shop and Giant come up with a fix that's satisfactory to you.
If you're curious, the fix consisted of (1) dripping oil into the bolt/rivnut junction to facilitate the bolt's breaking free; (2) grabbing the flange of the rivnut by carefully tightening a Vice-Grip on it, just firmly enough to keep it from spinning but not enough to extensively deform it; and (3) carefully backing the bolt out of the rivnut. I used strips of electrical tape to protect the bike's paint job from the Vice-Grip, of course. Once the bolt was out, it was easy to fix the rivnut as detailed in the video I posted earlier.