Listening to music through headphones while cycling? Bonkers. How can you possibly concentrate on the most important thing, such as the stretto in an atonal Shostakovich fugue, with all that traffic noise putting you off?
But seriously... it does seem a pretty stupid thing to do. Navigating through central London requires an undistracted brain at full capacity. It's a cacophony of crazy people yelling at each other, blaring horns, and droning wind noise. And that's just the Wagner.
And, curiously, the cyclists you see nodding their heads along in a world of their own to an unseen drum'n'bass all wear helmets. Better not to come to grief in the first place. A south London inquest yesterday dealt with the dreadfully sad case of a student who was run down and killed by a tram from behind while listening to his iPod on his bike.
So I'm not convinced either by the announcement the other day by Taiwanese firm Agios Technology. The Podio is a handlebar-mounted, front-light-sized hi-fi for cyclists: a 2GB MP3 player with a built-in 1.5W speaker and up to 20 hours of battery life.
Oh no! I don't like the idea of every traffic-light stop on my way to work bombarding me with other people's music. They might like Celine Dion or Nine Inch Nails or Wagner, but I don't want it sledgehammered at me by the lights at The Cut while my breakfast is still going down.
But maybe there are more inventive uses for it. You could have Abba playing as you cross Waterloo Bridge. The Kinks on the way back over at sunset. Gerry Rafferty down Baker Street. Holst's Hammersmith in Hammersmith.
Or perhaps just recorded messages of abuse to save you shouting at bus drivers.