Might work, but the stem where shifters usually clamp is 7/8" (22.2mm) diameter. You're back to where you started with an undersize clamp. A steel clamp might "stretch" with an extra-long screw.
Hopefully I won't have to go there, but that was exactly my thought. Right now I have a 22.2 chromed steel drop bar, so it wouldn't be an issue. It's only 38cm wide, hopefully enough for my wife! She can ride a 39cm so fingers crossed!!
