Rack attack

I experienced a startling incident on my ride home today: my bicycle rack popped off. Two of the four screws had worked themselves out without my noticing; I'd occasionally heard something rubbing against the rear wheel, and assumed it was the straps on my pannier. But no; it was the rack flexing between its two points of attachment. Today, a third screw escaped, leaving the rack attached by one screw at the rear axle. It swung around that pivot and, weighted by my pannier, bit into my rear wheel, acting as a sort of guillotine brake.

Fortunately, I was on a bike path, not in traffic. After a burst of panicked what-the-hell-was-that-noise? adrenaline, I was able to stop without incident. I've been travelling with a little Allen key, so I was able to get everything back ship-shape — I found the missing screw lying in the bike path behind me (amazingly), and suborned two unused screws from the bottle-holder slots on the frame — but I'm glad I'd already made a maintenance appointment for Monday.