Framebuilders - Downtube shifters

My frame has only one shifter control mounted on a braze on.
I'd like to add a second one, on the other side of the downtube, but I cannot weld a braze on for it cause I'll have to repaint the frame...
I thought that I could add a pair of clamp-on shifters like this one (http://upload.wikimedia.org/wikipedia/commons/c/cf/Downtube_shifters.JPG) and remove the right shifter control from it in order to be placed over the existing braze on the frame. Has anyone tried something similar? Is it possible to Any advice could be very helpful.

what kind of bike is it? Seems that at least one company built a clamp on shifter with only the left side lever, and the right side had a hole to go around the braze on.

It is a vintage peugeot. Where could I find such a clamp?

I wonder if you could rivet one on, or would that not be strong enough?

I wouldn't like to hurt the frame...

It is a vintage peugeot. Where could I find such a clamp?
started out as a 5 speed?

As a 3-speed.

Yes that sounds like the old Peugeots. My local coop has some of the corresponding one-sided shifter clamps.

Besides finding the clamp, you can grind the boss that is there? That only will leave a small unpainted spot. Hacksaw what you can then *carefully* file the remainder flush to the tube. You'll probably need to secure the tube in a vise w/ a tube block.

Here is a clamp-on that goes over the existing boss on opposite side,
http://roadbikeshifters.com/29-99-simplex-downtube-shifters-clamp-one-sided-index-ready-sti-suntour-campagnolo/

THere were somewhat commonly used back in 50's/60's to upgrade older bikes that came with antiqated front deraillers that shifted via linkage rod on the seattube instead of via cable. During this era, plenty of nice bikes were made with just a right side shifter boss and when cable pull FD became cutting edge old bikes needed a similar shifter clamp to add just a L-side boss.

You could always fab up a lever-operated shifter for the front. :thumb:

It is a vintage peugeot. Where could I find such a clamp?

This is the part you need:

http://www.os2.dhs.org/~john/ref2954.jpg


They haven't been made in decades, but many French bike-boom era bikes came with them. Is there a co-op nearby with a parts bin you could search?

It sounds like brazing/welding is an available option, so if you can do that, making a clamp like that would be a fun afternoon project.

Use the frame for what it was meant to do. If it's not built for something you want to do, leave it alone and build another. Makes the most sense to me, after all, it's not hard to just build another.