Water Bottle Holder holes

[Bill]

Here are one of times that asked. Anyone know how to drill and tap the holes for a water bottle holder? What metal is good for this? Which type of alloy is not a good idea to do this procedure? I have done many things, but this is one I have been considering. Any and all advice is welcome.

[cyclerUK]

A lot of frames, especially aluminium, have what we call a "Rivnut" installation for the bottle screws.
See:- http://www.enfasco.com/frame4.htm
It's sort of a pop rivet design.
The only problem with these is that they can start to spin in their hole, if not fixed securely, so making it difficult to undo!
Steel frames usually have a small raised boss welded or soldered in place then tapped.
I presume most holes are 5mm tapped?

[xerxes]

I wouldn't drill holes anywhere in any frame for fear of creating a weak spot which may lead to stress fractures.

I don't have much experience with aluminium frames, but on steel frames the bottle cage bosses are braized onto the frame. Steel frames are incredibly thin, especially lightweight cromolly or reynolds tubed frames, where the tube walls are as thin as 0.3mm, so the braize on serves to reinforce the hole as well as provide enough depth for the thread.

For frames with no bosses, try something like this: http://www.sjscycles.co.uk/product-Elite-Elite-VIP-Bottle-Cage-Clamps-22--50-mm-Diameter-13892.htm

[cyclerUK]

Take your pick?
http://www.nordicgroup.us/cageboss/

[Bill]

Great Ideas!! I think I will veer away from my original idea. Plenty of panniers or other addon accessories without ruining a perfectly good frame .