• THE letter (Bike abuse, December 14) brought to mind the following, found years ago in a Christmas cracker: “Knock, knock. Who’s there? Isabel. Isabel who? Isabel necessary on a bicycle?”

Answer: It most certainly is, plus functioning brakes, front and rear lights, a properly fitting helmet and a modicum of good manners, including not cycling on the pavement, designed specifically as a safe space for pedestrians.

MARIAN KAMLISH, NW1