I can tell from the look of irritation mixed with despair on the mechanics' face. They've been adjusted twice now but keep on giving me trouble, like obnoxious teenagers looking for the next prank to play. "What can we do next that will put M. in mortal danger, as she hurtles down a hill towards a busy roundabout? Ooooh, I know!"
This time the front brake has been misbehaving, refusing to spring back to its original position when released, creating a drag on the wheel that makes me feel particularly unfit as I struggle up gentle inclines. After poking fecklessly at the mechanism for a while, and even more aimlessly at the internets, I came across this refreshingly clear guide to adjusting my sidepull calliper brake (for such is apparently the name of the mechanism).
It seems like the back nut was just too tight, stopping the brake from springing open on one side. I've loosened it slightly, and it seems to be working fine now.
I feel like Sherpa Tenzing, having just conquered an impregnable summit, armed only with cranky frustration and a multi-spanner tool thingamajiggy.
What did you do Sunday night? I took photos of my spanner. Sigh.