--- In bentechriders@yahoogroups.com, "Edward" <edsyahoo@...> wrote:

> I'm thinking of cutting some circular caps out of the same steel plate
> I made the dropouts from, then brazing them to the inside of the
> tubes. However, I thought I'd ask: can anyone think of any reason why
> I *shouldn't* close up these tubes

The derailleur stem tube makes a good mounting point for fairings, and
many of them have booms that slip into the tube. You may want to design
some kind of mount for that spot in the future and your options will be
limited if you weld it shut.

My frame kit came with a plug for the tube. It's like a bar end plug -
a flat metal disc held in with friction tabs. If you're concerned about
rain, I'd go with this solution. If you decide to use the stem for a
fairing or anything else, you'll have options. I've never had any
problem with the plug on my SWB.

Oh, and if you do decide to weld it shut, you'll need to leave a snall
hole in the cap to release the hot gases in the tube during welding. If
you try to seal it all in one go, you may get a nasty spray of molten
metal directed toward you as you attempt to close the last escape point
of the heated gas. You can quickly close the small hole after the metal
has cooled way down. It shouldn't take much heat to plug it.

All things considered, a plastic or metal tube plug is the easier way
to go.

Jim