A quicky to the shops. The new chain and cassette have performed black magic.
I click the gears - there is zero noise - and I'm in another gear.
Previously the gears would resist any change, "Seriously?", says the drivetrain, "You changed gear a minute ago!".
So you stab the gear with more authority - to show it who is boss.
The drivetrain puts down its newspaper. Complains as it stubs out its cigarette. Pulls whatever levers, cranks and pulleys are necessary which begins a cacophony of clatter, grind and smashing sounds. Think Houdini, with a hangover, bound by three furlongs of chain and ten locks. Thrown into a large washing machine. That's then pushed down a metal staircase. Expensive, unhappy, mechanical sounds.
Several false changes tease you, before snaping back into the symphony of mechanical agony. And just before you stab the lever again - the gear heralds its arrival with a clank and shudder that shakes the rain drops from the frame.
I think I'll change the chain earlier next time...