I've scored a Syntace Brake Lever for my bullhorns. They are designed to run the brake cable inside the handlebars, so I need an exit hole. In the past I've seen handlebars that have been drilled for internal routing - often done by the owner, not the manufacturer. I already know that Syntace makes bars for this lever, but I'd like to avoid spending more money.
Anyone out there drilled a hole in their handlebars for themselves? How bad an idea is this? Where would be the best spot on the bars to put a hole?
The smaller the hole the better - chamfer the edges of the hole with a small-diameter rat-tail file to avoid stress risers. If you get any burrs, polish them off with emery cloth. Put the hole where the factory puts theirs. Since the factory does this, hopefully there'll be enough margin of safety in the bars for you to do it too. Good luck!