I once came across a claim that a properly sharpened screwdriver was an indispensable tool.
Maybe you’ve done this: File a v-channel into the tip of a screwdriver, which keeps it from slipping off the spring of a single-pivot sidepull brake spring. Then tap the other end of the screwdriver and, voila, the brake moves to one side, which centers the brake shoes on either side of the rim.
If you haven’t done it, it works. It’s brutal, but it works.
Like that idea? Here’s one for derailleurs. And good news, it’s more brutal.
Shimano bar ends don’t normally have enough travel to fully motivate a SRAM derailleur across 10 cassette cogs–the parts feature different cable-pull lengths.
Solution? Remove the cove above the lever of a nine-speed bar-end shifter. Now the lever can point at the sky as well as the ground, and you have something that plays nice (in friction mode) with a SRAM 10-speed rear derailleur.
All it takes is a hacksaw, though if you have the time you might add a little judicious file work for the sake of aesthetics.
Or you can do what I eventually did and install a SRAM Apex brake-shift unit. It doesn’t offer a friction mode but it’s so good otherwise you’d think it was made for the job.