Its come loose, so the screw cant get any traction.

Any advice other than owning it with superglue?

alu frame.

You mean the threads in the frame are stripped ?
You could drill the rivnuts out and fit new ones.

There is a tool which splays them out so them hold the frame properly. Your LBS might have one

We’ve got the tool for setting rivnuts at work.
I wouldn’t want to rely on resetting a rivnut that’s come loose, I’d rather replace it. It’s only a bottle cage though, so it might be worth a try.

What exactly is the problem ?
Thread stripped or rivnut turning in the frame ?

Thanks for the replies.

Its the rivnut (after googling) thats loose, so it moves when the bottle cage screw is tightened or loosened.
Thread is fine.

I have successfully reset a loose rivnut – ask a decent LBS

I did mine yesterday., what is the name of your parallel universe?

Just like you the bolt would not come out and the rivnut just span. I WD40’d it, poured boiling water on it, heated it with a blowtorch (bare frame) and finally I superglued the rivnut in place. After 5mins for the glue to set to my surprise I was then able to turn the bolt and the rivnut stayed in place. I am not sure if skipping to the superglue straight away would have worked on it’s own but that’s what I did. I just put a well greased bolt back in since I am not using the mount at present.

I understand that a rivnut setting tool can be used to tighten loosened rivnuts (it’s a bit like a pop riviter) or there is a longbolt, nut, washer bodge that I may try:
http://blogs.sun.com/chrisg/entry/tightening_a_rivnut

There is loads on the web just google rivnut or nutsert and bike frame.

Good luck.

That description of tightening a rivnut is what I did.

Top tip: only works once you have got your bolt out of the boss though…

Get an M5 bolt and wind an M5 nut half way down it. Screw the bolt into your bottle cage boss until you get to the nut. Then hold the bolt with an allen key and tighten the nut towards the frame with a spanner. This re-compresses the boss onto the frame and should stop it from moving.

There is also a proper tool for this which, as mentioned above, your LBS will probably have. Bolt and nut works well though!