Originally Posted by
Thirstyman
My 1981 steel framed bike has no threaded mounts for water bottles. So I'm considering drilling and tapping the seat and head tube on a steel frame (tube walls look about 1/8" thick). Is that as bad of an idea as I'm thinking or is the frame so overbuilt that it's not a problem? Have others done this? I have attached the cages with cheap bolt-on rings but it looks like complete crap ends up working loose as they fit poorly to begin with. I have completely rebuilt this bike from the frame up with new Ultegra/SL parts so just considering upgrading this too.
If the frame is built with straight-gauge tubing, it should be fine. I did this on my home-built tandems, no problems.
I knew a guy once who even used self-tapping sheet metal screws for this on some old beater.
I wouldn't do this on a butted frame though.
Sheldon "Taps" Brown